Universal Divine Living in Diversity- The Universe, Body, Mind and Spirit Connection

Universal Divine Living The Trinity in Universal Divinity and Diversity Father, Mother and Child (Boy and Daughter) God, Mary and Jesus Spirit, Body and Mind Primate, Human and Divine Faith, Food and Fitness Universal Divinity with self, family and friends The life and legacy of Divinity in all of us Universal Divine Living: Living 4 Others (Diversity) The Universal Divine Diet Movement: 3F: Faith, food and Fitness Integrating our Body, Mind and Spirit and our Primate, Human and Divine Living The trinity of divine living 1 Divinity and Diversity begins within our ecosystem that is our home and community- with self, family and friends. 2 Divine Love yourself first before you love and serve others. 3 Divine love means respect, dignity and connection to the Universal Divine God, who is just, omniscient, omnipresent and loves all his creation and humans equally. Defining Divine living: • Developing the habit, the option, and will power and the mindset to Be Divine at all times- (Living 4 Others). The trinity of Divine habit Our Divine body needs balanced nutrition, productivity and restful sleep Our Divine resources are our integrated Divine self (body, mind, and spirit) We need to integrate our lives in time, place and person, the three dimensions of life on earth and the universe. The trinity of Divine time Serving others with time and energy of life The 8:8:8 rule (8 hours sleep, 8 hours productivity and 8 hours leisure) The Science of Divine life Balanced food, balanced (isometric and isotonic exercise) and restful sleep, generates the good hormones, boosts our immunity and allows more blood flow to the brain that allows us to make better choice and better decision. Divine Diversity in faith, food, and fitness leads to Diversity in life that is Divine and gives us the Divine resources to serve others Biodiversity in food: Organic and balanced diet that has multiple colors, taste and biodiversity in food value. Divine Nutrition The Rainbow/Vibgryo Diet: Violent Indigo, Brown, Green, Yellow and Orange. The normal light and color spectrum Eating food of diverse colors and value, at least three colors per serving Our Divine Body The body is the holy temple of the Divine. Our BMI (Body Mass Index) is a critical measure of our health (BMI=Weight/height x height). 1 One in three (1:3) Americans are obese: BMI>30, sickness 2 The Dinosaur mind: brain shrinks as body size increases 3 Good habit: It takes 6 weeks to develop a habit (40 days); 40 days to a healthier you The Divine Life is a second to second, minute-to-minute, hour-to-hour, day by day positive experience. Faith, Food and Fitness for Diving Living The Trinity in Divinity and Diversity Father, Mother and Child God, Mary and Jesus Spirit, Body and Mind Primate, Human and Divine Faith, Food and Fitness Divinity with self, family and friends The life and legacy of Divinity in all of us Divine Living: Living 4 Others! The Divine Diet Movement: 3F: Faith, food and Fitness Integrating our Body, Mind and Spirit and our Primate, Human and Divine Living The trinity of divine living 4 Divinity and Diversity begins within our ecosystem that is our home and community- with self, family , friends and community at large. 5 Divine Love yourself first before you love and serve others. 6 Divine love means respect, dignity and connection to the Universal Divine God, who is just, omniscient, omnipresent and loves all his creation and humans equally. Defining Divine living: • Developing the habit, the option, and will power and the mindset to Be Divine at all times- (Living 4 Others). The trinity of Divine habit Our Divine body needs balanced nutrition, productivity and restful sleep Our Divine resources are our integrated Divine self (body, mind, and spirit) We need to integrate our lives in time, place and person, the three dimensions of life on earth and the universe. The trinity of Divine time, energy and matter (Body, Mind and Spirit) Serving others with time and energy of life The 8:8:8 rule (8 hours sleep, 8 hours productivity and 8 hours leisure) The Science of Divine living Divine living is an integrated Balanced food, balanced (isometric and isotonic exercise) and restful sleep, generates the good hormones, boosts our immunity and allows more blood flow to the brain that allows us to make better choice and better decision. Divine Diversity in faith, food, and fitness leads to Diversity in life that is Divine and gives us the Divine resources to serve others Biodiversity in food: Organic and balanced diet that has multiple colors, taste and biodiversity in food value. Divine Nutrition The Rainbow/Vibgryo Diet: Violent Indigo, Brown, Green, Yellow and Orange. The normal light and color spectrum Eating food of diverse colors and value, at least three colors per serving Our Divine Body The body is the holy temple of the Divine. Our BMI (Body Mass Index) is a critical measure of our health (BMI=Weight/height x height). 4 One in three (1:3) Americans are obese: BMI>30, sickness 5 The Dinosaur mind: brain shrinks as body size increases 6 Good habit: It takes 6 weeks to develop a habit (40 days); 40 days to a healthier you The Divine Life is a second to second, minute-to-minute, hour-to-hour, day by day positive experience. Faith, Food and Fitness for Diving Living The Trinity in Divinity and Diversity Father, Mother and Child God, Mary and Jesus Spirit, Body and Mind Primate, Human and Divine Faith, Food and Fitness Divinity with self, family and friends The life and legacy of Divinity in all of us Divine Living: Living 4 Others! The Divine Diet Movement: 3F: Faith, food and Fitness Integrating our Body, Mind and Spirit and our Primate, Human and Divine Living The trinity of divine living 1. Divinity and Diversity begins within our ecosystem that is our home and community- with self, family and friends. 2. Divine Love yourself first before you love and serve others. 3. Divine love means respect, dignity and connection to the Universal Divine God, who is just, omniscient, omnipresent and loves all his creation and humans equally. Defining Divine living: • Developing the habit, the option, and will power and the mindset to Be Divine at all times- (Living 4 Others). The trinity of Divine habit Our Divine body needs balanced nutrition, productivity and restful sleep Our Divine resources are our integrated Divine self (body, mind, and spirit) We need to integrate our lives in time, place and person, the three dimensions of life on earth and the universe. The trinity of Divine time Serving others with time and energy of life The 8:8:8 rule (8 hours sleep, 8 hours productivity and 8 hours leisure) The Science of Divine life Balanced food, balanced (isometric and isotonic exercise) and restful sleep, generates the good hormones, boosts our immunity and allows more blood flow to the brain that allows us to make better choice and better decision. Divine Diversity in faith, food, and fitness leads to Diversity in life that is Divine and gives us the Divine resources to serve others Biodiversity in food: Organic and balanced diet that has multiple colors, taste and biodiversity in food value. Divine Nutrition The Rainbow/Vibgryo Diet: Violent Indigo, Brown, Green, Yellow and Orange. The normal light and color spectrum Eating food of diverse colors and value, at least three colors per serving Our Divine Body The body is the holy temple of the Divine. Our BMI (Body Mass Index) is a critical measure of our health (BMI=Weight/height x height). 7 One in three (1:3) Americans are obese: BMI>30, sickness 8 The Dinosaur mind: brain shrinks as body size increases 9 Good habit: It takes 6 weeks to develop a habit (40 days); 40 days to a healthier you The Divine Life is a second to second, minute-to-minute, hour-to-hour, day-by-day positive experience. Faith, Food and Fitness for Diving Living The Trinity in Divinity and Diversity Father, Mother and Child God, Mary and Jesus Spirit, Body and Mind Primate, Human and Divine Faith, Food and Fitness Divinity with self, family and friends The life and legacy of Divinity in all of us Divine Living: Living 4 Others! The Divine Diet Movement: 3F: Faith, food and Fitness Integrating our Body, Mind and Spirit and our Primate, Human and Divine Living The trinity of divine living 1. Divinity and Diversity begins within our ecosystem that is our home and community- with self, family and friends. 2. Divine Love yourself first before you love and serve others. 3. Divine love means respect, dignity and connection to the Universal Divine God, who is just, omniscient, omnipresent and loves all his creation and humans equally. Defining Divine living: • Developing the habit, the option, and will power and the mindset to Be Divine at all times- (Living 4 Others). The trinity of Divine habit Our Divine body needs balanced nutrition, productivity and restful sleep Our Divine resources are our integrated Divine self (body, mind, and spirit) We need to integrate our lives in time, place and person, the three dimensions of life on earth and the universe. The trinity of Divine time Serving others with time and energy of life The 8:8:8 rule (8 hours sleep, 8 hours productivity and 8 hours leisure) The Science of Divine life Balanced food, balanced (isometric and isotonic exercise) and restful sleep, generates the good hormones, boosts our immunity and allows more blood flow to the brain that allows us to make better choice and better decision. Divine Diversity in faith, food, and fitness leads to Diversity in life that is Divine and gives us the Divine resources to serve others Biodiversity in food: Organic and balanced diet that has multiple colors, taste and biodiversity in food value. Divine Nutrition The Rainbow/Vibgryo Diet: Violent Indigo, Brown, Green, Yellow and Orange. The normal light and color spectrum Eating food of diverse colors and value, at least three colors per serving Our Divine Body The body is the holy temple of the Divine. Our BMI (Body Mass Index) is a critical measure of our health (BMI=Weight/height x height). 1. One in three (1:3) Americans are obese: BMI>30, sickness 2. The Dinosaur mind: brain shrinks as body size increases 3. Good habit: It takes 6 weeks to develop a habit (40 days); 40 days to a healthier you The Divine Life is a second to second, minute-to-minute, hour-to-hour, day by day positive experience. Faith, Food and Fitness for Diving Living Universal Divine Living: The Universe, the Divine, The Human Body, The Human Mind, the Human Spirit We are at the beginning of the eighth millennia (7500-8,500). Many consider this to be the beginning of the last days or the end of time. Many consider this is a special time of the expansion of knowledge about the universe and the cosmos. It is the end of ignorance and the beginning of knowledge, wisdom and instant information. The computer and Internet revolution and information super highway is the beginning of this new world of instant information, and the expansion of knowledge. The presence of ICT (Information, Communication Technology, and SMN (Social Media Network) is making these new beginnings really interesting. This is December in 7506 according to the Ethiopian Calendar, the oldest and perhaps the most accurate calendar since humans began to document time as we know it. We will review the Universal Diving Living series by looking at the new information we have on the Universe, the Divine, the Human Body, the Human Mind and the Human Spirit so as to understand this new Universal Divine Living, the beginning of the new Universal Order and the new Universal Divine Living. We will examine the latest information on the Universe, the Divine, the Human Body, the Human Mind and the Human Spirit. We will look at the scientific and material evidence of the universe in all its totality to discover what Universal Divine Life offers. The Universe- the Cosmos, the Expanding universe , age of the Universe , the Big Bang, Chronology of the Universe Universe From Wikipedia, the free encyclopedia For other uses, see Universe (disambiguation). Part of a series on Physical cosmology • Universe • Big Bang • Age of the universe • Chronology of the universe Early universe[show] Expanding universe[show] Structure formation[show] Future of universe[show] Components[show] History[show] Experiments[show] Scientists[show] Social impact[show] • Astronomy portal • Category: Physical cosmology • V • T • E The Universe is commonly defined as the totality of existence,[1][2][3][4] including planets, stars, galaxies, the contents of intergalactic space, and all matter andenergy.[5][6] Similar terms include the cosmos, the world and nature. The observable universe is about 46 billion light years in radius.[7] Scientific observation of the Universe has led to inferences of its earlier stages. These observations suggest that the Universe has been governed by the same physical laws and constants throughout most of its extent and history. The Big Bang theory is the prevailing cosmological model that describes the early development of the Universe, which is calculated to have begun 13.798 ± 0.037 billion years ago.[8][9]Observations of a supernovae have shown that the Universe is expanding at an accelerating rate.[10] There are many competing theories about the ultimate fate of the universe. Physicists remain unsure about what, if anything, preceded the Big Bang. Many refuse to speculate, doubting that any information from any such prior state could ever be accessible. There are various multiverse hypotheses, in which some physicists have suggested that the Universe might be one among many universes that likewise exist.[11][12] Contents • 1 History o 1.1 Observational history o 1.2 History of the Universe • 2 Etymology, synonyms and definitions o 2.1 Broadest definition: reality and probability o 2.2 Definition as reality o 2.3 Definition as connected space-time o 2.4 Definition as observable reality • 3 Size, age, contents, structure, and laws o 3.1 Fine tuning • 4 Historical models o 4.1 Creation o 4.2 Philosophical models o 4.3 Astronomical models • 5 Theoretical models o 5.1 General theory of relativity o 5.2 Special relativity and space-time o 5.3 Solving Einstein’s field equations o 5.4 Big Bang model o 5.5 Multiverse theory • 6 Shape of the Universe • 7 See also • 8 Notes and references • 9 Bibliography • 10 Further reading • 11 External links o 11.1 Videos History Observational history Hubble eXtreme Deep Field (XDF) XDF size compared to the size of theMoon – several thousand galaxies, each consisting of billions of stars, are in this small view. XDF (2012) view – each light speck is agalaxy – some of these are as old as 13.2 billion years[13] – the visible Universe is estimated to contain 200 billion galaxies. XDF image shows fully mature galaxiesin the foreground plane – nearly mature galaxies from 5 to 9 billion years ago –protogalaxies, blazing with young stars, beyond 9 billion years. Throughout recorded history, several cosmologies and cosmogonies have been proposed to account for observations of the Universe. The earliest quantitative geocentricmodels were developed by the ancient Greek philosophers. Over the centuries, more precise observations and improved theories of gravity led to Copernicus’sheliocentric model and the Newtonian model of the Solar System, respectively. Further improvements in astronomy led to the realization that the Solar System is embedded in a galaxy composed of billions of stars, the Milky Way, and that other galaxies exist outside it, as far as astronomical instruments can reach. Careful studies of the distribution of these galaxies and their spectral lines have led to much of modern cosmology. Discovery of the red shift and cosmic microwave background radiation suggested that the Universe is expanding and had a beginning.[14] History of the Universe Main article: Chronology of the universe According to the prevailing scientific model of the Universe, known as the Big Bang, the Universe expanded from an extremely hot, dense phase called the Planck epoch, in which all the matter and energy of the observable universe was concentrated. Since the Planck epoch, the Universe has been expanding to its present form, possibly with a brief period (less than 10−32 seconds) of cosmic inflation. Several independent experimental measurements support this theoretical expansion and, more generally, the Big Bang theory. The universe is composed of ordinary matter (5%) including atoms, stars, and galaxies, dark matter (25%) which is a hypothetical particle that has not yet been detected, and dark energy (70%), which is a kind of energy density that seemingly exists even in completely empty space.[15] Recent observations indicate that this expansion is accelerating because of dark energy, and that most of the matter in the Universe may be in a form which cannot be detected by present instruments, called dark matter.[16] The common use of the “dark matter” and “dark energy” placeholder names for the unknown entities purported to account for about 95% of the mass-energy density of the Universe demonstrates the present observational and conceptual shortcomings and uncertainties concerning the nature andultimate fate of the Universe.[17] On 21 March 2013, the European research team behind the Planck cosmology probe released the mission’s all-sky map of the cosmic microwave background.[18][19][20][21][22] The map suggests the universe is slightly older than thought. According to the map, subtle fluctuations in temperature were imprinted on the deep sky when the cosmos was about 370,000 years old. The imprint reflects ripples that arose as early, in the existence of the universe, as the first nonillionth (10−30) of a second. Apparently, these ripples gave rise to the present vast cosmic web of galaxy clusters and dark matter. According to the team, the universe is 13.798 ± 0.037 billion years old,[9][23] and contains 4.9% ordinary matter, 26.8% dark matter and 68.3% dark energy. Also, the Hubble constant was measured to be 67.80 ± 0.77 (km/s)/Mpc.[18][19][20][22][23] An earlier interpretation of astronomical observations indicated that the age of the Universe was 13.772 ± 0.059 billion years,[24] and that the diameter of the observable universe is at least 93 billion light years or 8.80×1026 meters.[25] According to general relativity, space can expand faster than the speed of light, although we can view only a small portion of the Universe due to the limitation imposed by light speed. Since we cannot observe space beyond the limitations of light (or any electromagnetic radiation), it is uncertain whether the size of the Universe is finite or infinite. Etymology, synonyms and definitions See also: Cosmos, Nature, World (philosophy), and Celestial spheres The word Universe derives from the Old French word Univers, which in turn derives from the Latin word universum.[26] The Latin word was used by Cicero and later Latin authors in many of the same senses as the modern English word is used.[27] The Latin word derives from the poetic contraction Unvorsum — first used by Lucretius in Book IV (line 262) of his De rerum natura (On the Nature of Things) — which connects un, uni (the combining form of unus, or “one”) with vorsum, versum (a noun made from the perfect passive participle of vertere, meaning “something rotated, rolled, changed”).[27] An alternative interpretation of unvorsum is “everything rotated as one” or “everything rotated by one”. In this sense, it may be considered a translation of an earlier Greek word for the Universe, περιφορά, (periforá, “circumambulation”), originally used to describe a course of a meal, the food being carried around the circle of dinner guests.[28] This Greek word refers to celestial spheres, an early Greek model of the Universe. Regarding Plato’s Metaphor of the sun, Aristotle suggests that the rotation of the sphere of fixed stars inspired by the prime mover, motivates, in turn, terrestrial change via the Sun. Careful astronomical and physical measurements (such as theFoucault pendulum) are required to prove the Earth rotates on its axis. A term for “Universe” in ancient Greece was τὸ πᾶν (tò pán, The All, Pan (mythology)). Related terms were matter, (τὸ ὅλον, tò ólon, see also Hyle, lit. wood) and place (τὸ κενόν, tò kenón).[29][30] Other synonyms for the Universe among the ancient Greek philosophers included κόσμος (cosmos) and φύσις (meaning Nature, from which we derive the word physics).[31] The same synonyms are found in Latin authors (totum, mundus, natura)[32] and survive in modern languages, e.g., the German words Das All, Weltall, and Natur for Universe. The same synonyms are found in English, such as everything (as in the theory of everything), the cosmos (as in cosmology), the world (as in the many-worlds interpretation), and Nature (as in natural laws or natural philosophy).[33] Broadest definition: reality and probability See also: Essence–Energies distinction#Distinction between created and uncreated The broadest definition of the Universe is found in De divisione naturae by the medieval philosopher and theologian Johannes Scotus Eriugena, who defined it as simply everything: everything that is created and everything that is not created. Definition as reality See also: Reality and Physics More customarily, the Universe is defined as everything that exists, (has existed, and will exist)[citation needed]. According to our current understanding, the Universe consists of three principles: spacetime, forms of energy, including momentum and matter, and the physical laws that relate them. Definition as connected space-time See also: Eternal inflation It is possible to conceive of disconnected space-times, each existing but unable to interact with one another. An easily visualized metaphor is a group of separate soap bubbles, in which observers living on one soap bubble cannot interact with those on other soap bubbles, even in principle. According to one common terminology, each “soap bubble” of space-time is denoted as a universe, whereas our particular space-time is denoted as the Universe, just as we call our moon the Moon. The entire collection of these separate space-times is denoted as the multiverse.[34] In principle, the other unconnected universes may have different dimensionalities and topologies of space-time, different forms of matter and energy, and different physical laws and physical constants, although such possibilities are purely speculative. Definition as observable reality See also: Observable universe and Observational cosmology According to a still-more-restrictive definition, the Universe is everything within our connected space-time that could have a chance to interact with us and vice versa.[citation needed] According to the general theory of relativity, some regions of space may never interact with ours even in the lifetime of the Universe due to the finite speed of light and the ongoing expansion of space. For example, radio messages sent from Earth may never reach some regions of space, even if the Universe would live forever: space may expand faster than light can traverse it. Distant regions of space are taken to exist and be part of reality as much as we are, yet we can never interact with them. The spatial region within which we can affect and be affected is the observable universe. Strictly speaking, the observable Universe depends on the location of the observer. By traveling, an observer can come into contact with a greater region of space-time than an observer who remains still. Nevertheless, even the most rapid traveler will not be able to interact with all of space. Typically, the observable Universe is taken to mean the Universe observable from our vantage point in the Milky Way Galaxy. Size, age, contents, structure, and laws Main articles: Observable universe, Age of the universe, and Abundance of the chemical elements The size of the Universe is unknown; it may be infinite. The region visible from Earth (the observable universe) is a sphere with a radius of about 46 billion light years,[35] based on where the expansion of spacehas taken the most distant objects observed. For comparison, the diameter of a typical galaxy is 30,000 light-years, and the typical distance between two neighboring galaxies is 3 million light-years.[36] As an example, the Milky Way Galaxy is roughly 100,000 light years in diameter,[37] and the nearest sister galaxy to the Milky Way, the Andromeda Galaxy, is located roughly 2.5 million light years away.[38] There are probably more than 100 billion (1011) galaxies in the observable Universe.[39] Typical galaxies range from dwarfs with as few as ten million[40] (107) stars up to giants with one trillion[41] (1012) stars, all orbiting the galaxy’s center of mass. A 2010 study by astronomers estimated that the observable Universe contains 300 sextillion (3×1023) stars.[42] The Universe is believed to be mostly composed of dark energy and dark matter, both of which are poorly understood at present. Less than 5% of the Universe is ordinary matter, a relatively small contribution. The observable matter is spread homogeneously (uniformly) throughout the Universe, when averaged over distances longer than 300 million light-years.[43] However, on smaller length-scales, matter is observed to form “clumps”, i.e., to cluster hierarchically; many atoms are condensed into stars, most stars into galaxies, most galaxies into clusters, superclusters and, finally, the largest-scale structures such as the Great Wall of galaxies. The observable matter of the Universe is also spreadisotropically, meaning that no direction of observation seems different from any other; each region of the sky has roughly the same content.[44] The Universe is also bathed in a highly isotropic microwave radiation that corresponds to a thermal equilibrium blackbody spectrum of roughly 2.725 kelvin.[45] The hypothesis that the large-scale Universe is homogeneous and isotropic is known as the cosmological principle,[46] which is supported by astronomical observations. The present overall density of the Universe is very low, roughly 9.9 × 10−30 grams per cubic centimetre. This mass-energy appears to consist of 73% dark energy, 23% cold dark matter and 4% ordinary matter. Thus the density of atoms is on the order of a single hydrogen atom for every four cubic meters of volume.[47] The properties of dark energy and dark matter are largely unknown. Dark matter gravitates as ordinary matter, and thus works to slow the expansion of the Universe; by contrast, dark energy accelerates its expansion. The current estimate of the Universe’s age is 13.798 ± 0.037 billion years old.[9] The Universe has not been the same at all times in its history; for example, the relative populations of quasars and galaxies have changed and space itself appears to have expanded. This expansion accounts for how Earth-bound scientists can observe the light from a galaxy 30 billion light years away, even if that light has traveled for only 13 billion years; the very space between them has expanded. This expansion is consistent with the observation that the light from distant galaxies has been redshifted; the photons emitted have been stretched to longer wavelengths and lower frequency during their journey. The rate of this spatial expansion is accelerating, based on studies of Type Ia supernovae and corroborated by other data. The relative fractions of different chemical elements — particularly the lightest atoms such as hydrogen, deuterium and helium — seem to be identical throughout the Universe and throughout its observable history.[48] The Universe seems to have much more matter than antimatter, an asymmetry possibly related to the observations of CP violation.[49] The Universe appears to have no net electric charge, and therefore gravity appears to be the dominant interaction on cosmological length scales. The Universe also appears to have neither net momentum nor angular momentum. The absence of net charge and momentum would follow from accepted physical laws (Gauss’s law and the non-divergence of the stress-energy-momentum pseudotensor, respectively), if the Universe were finite.[50] The elementary particles from which the Universe is constructed. Six leptons and six quarks comprise most of the matter; for example, the protons and neutrons of atomic nuclei are composed of quarks, and the ubiquitous electronis a lepton. These particles interact via the gauge bosonsshown in the middle row, each corresponding to a particular type of gauge symmetry. The Higgs boson is believed to confer mass on the particles with which it is connected. Thegraviton, a supposed gauge boson for gravity, is not shown. The Universe appears to have a smooth space-time continuum consisting of three spatial dimensions and one temporal (time) dimension. On the average, space is observed to be very nearly flat (close to zero curvature), meaning that Euclidean geometry is experimentally true with high accuracy throughout most of the Universe.[51] Spacetime also appears to have a simply connected topology, at least on the length-scale of the observable Universe. However, present observations cannot exclude the possibilities that the Universe has more dimensions and that its spacetime may have a multiply connected global topology, in analogy with the cylindrical or toroidal topologies of two-dimensional spaces.[52] The Universe appears to behave in a manner that regularly follows a set of physical laws and physical constants.[53] According to the prevailing Standard Model of physics, all matter is composed of three generations of leptons and quarks, both of which are fermions. These elementary particles interact via at most three fundamental interactions: the electroweak interaction which includes electromagnetism and the weak nuclear force; the strong nuclear forcedescribed by quantum chromodynamics; and gravity, which is best described at present by general relativity. The first two interactions can be described by renormalized quantum field theory, and are mediated by gauge bosons that correspond to a particular type of gauge symmetry. A renormalized quantum field theory of general relativity has not yet been achieved, although various forms of string theory seem promising. The theory of special relativity is believed to hold throughout the Universe, provided that the spatial and temporal length scales are sufficiently short; otherwise, the more general theory of general relativity must be applied. There is no explanation for the particular values that physical constants appear to have throughout our Universe, such as Planck’s constant h or the gravitational constant G. Several conservation laws have been identified, such as the conservation of charge, momentum, angular momentum and energy; in many cases, these conservation laws can be related to symmetries or mathematical identities. Fine tuning[edit] Main article: Fine-tuned Universe It appears that many of the properties of the Universe have special values in the sense that a Universe where these properties differ slightly would not be able to support intelligent life.[14][54] Not all scientists agree that this fine-tuning exists.[55][56] In particular, it is not known under what conditions intelligent life could form and what form or shape that would take. A relevant observation in this discussion is that for an observer to exist to observe fine-tuning, the Universe must be able to support intelligent life. As such the conditional probability of observing a Universe that is fine-tuned to support intelligent life is 1. This observation is known as the anthropic principle and is particularly relevant if the creation of the Universe was probabilistic or if multiple universes with a variety of properties exist (see below). Historical models[edit] See also: Cosmology and Timeline of cosmology Many models of the cosmos (cosmologies) and its origin (cosmogonies) have been proposed, based on the then-available data and conceptions of the Universe. Historically, cosmologies and cosmogonies were based on narratives of gods acting in various ways. Theories of an impersonal Universe governed by physical laws were first proposed by the Greeks and Indians. Over the centuries, improvements in astronomical observations and theories of motion and gravitation led to ever more accurate descriptions of the Universe. The modern era of cosmology began with Albert Einstein’s 1915 general theory of relativity, which made it possible to quantitatively predict the origin, evolution, and conclusion of the Universe as a whole. Most modern, accepted theories of cosmology are based on general relativity and, more specifically, the predicted Big Bang; however, still more careful measurements are required to determine which theory is correct. Creation[edit] Main articles: Creation myth and Creator deity Many cultures have stories describing the origin of the world, which may be roughly grouped into common types. In one type of story, the world is born from a world egg; such stories include the Finnish epic poem Kalevala, the Chinese story of Pangu or the Indian Brahmanda Purana. In related stories, the Universe is created by a single entity emanating or producing something by him- or herself, as in the Tibetan Buddhism concept of Adi-Buddha, the ancient Greek story of Gaia (Mother Earth), the Aztec goddess Coatlicue myth, the ancient Egyptian god Atum story, or the Genesis creation narrative. In another type of story, the Universe is created from the union of male and female deities, as in the Maori story of Rangi and Papa. In other stories, the Universe is created by crafting it from pre-existing materials, such as the corpse of a dead god — as from Tiamat in the Babylonian epic Enuma Elish or from the giant Ymir in Norse mythology – or from chaotic materials, as in Izanagi and Izanami in Japanese mythology. In other stories, the Universe emanates from fundamental principles, such as Brahman and Prakrti, the creation myth of the Serers,[57] or the yin and yang of the Tao. Philosophical models[edit] Further information: Cosmology See also: Pre-Socratic philosophy, Physics (Aristotle), Hindu cosmology, Islamic cosmology, and Time From the 6th century BCE, the pre-Socratic Greek philosophers developed the earliest known philosophical models of the Universe. The earliest Greek philosophers noted that appearances can be deceiving, and sought to understand the underlying reality behind the appearances. In particular, they noted the ability of matter to change forms (e.g., ice to water to steam) and several philosophers proposed that all the apparently different materials of the world are different forms of a single primordial material, or arche. The first to do so was Thales, who proposed this material is Water. Thales’ student, Anaximander, proposed that everything came from the limitless apeiron. Anaximenes proposed Air on account of its perceived attractive and repulsive qualities that cause the arche to condense or dissociate into different forms.Anaxagoras, proposed the principle of Nous (Mind). Heraclitus proposed fire (and spoke of logos). Empedocles proposed the elements: earth, water, air and fire. His four element theory became very popular. Like Pythagoras, Plato believed that all things were composed of number, with the Empedocles’ elements taking the form of the Platonic solids. Democritus, and later philosophers—most notably Leucippus—proposed that the Universe was composed of indivisible atoms moving through void (vacuum). Aristotle did not believe that was feasible because air, like water, offers resistance to motion. Air will immediately rush in to fill a void, and moreover, without resistance, it would do so indefinitely fast. Although Heraclitus argued for eternal change, his quasi-contemporary Parmenides made the radical suggestion that all change is an illusion, that the true underlying reality is eternally unchanging and of a single nature. Parmenides denoted this reality as τὸ ἐν (The One). Parmenides’ theory seemed implausible to many Greeks, but his student Zeno of Elea challenged them with several famous paradoxes. Aristotle responded to these paradoxes by developing the notion of a potential countable infinity, as well as the infinitely divisible continuum. Unlike the eternal and unchanging cycles of time, he believed the world was bounded by the celestial spheres, and thus magnitude was only finitely multiplicative. The Indian philosopher Kanada, founder of the Vaisheshika school, developed a theory of atomism and proposed that light and heat were varieties of the same substance.[58] In the 5th century AD, the Buddhist atomist philosopher Dignāga proposed atoms to be point-sized, durationless, and made of energy. They denied the existence of substantial matter and proposed that movement consisted of momentary flashes of a stream of energy.[59] The theory of temporal finitism was inspired by the doctrine of Creation shared by the three Abrahamic religions: Judaism, Christianity and Islam. The Christian philosopher, John Philoponus, presented the philosophical arguments against the ancient Greek notion of an infinite past and future. Philoponus’ arguments against an infinite past were used by the early Muslim philosopher, Al-Kindi (Alkindus); the Jewish philosopher, Saadia Gaon (Saadia ben Joseph); and the Muslim theologian, Al-Ghazali (Algazel). Borrowing from Aristotle’s Physics and Metaphysics, they employed two logical arguments against an infinite past, the first being the “argument from the impossibility of the existence of an actual infinite”, which states:[60] “An actual infinite cannot exist.” “An infinite temporal regress of events is an actual infinite.” ” An infinite temporal regress of events cannot exist.” The second argument, the “argument from the impossibility of completing an actual infinite by successive addition”, states:[60] “An actual infinite cannot be completed by successive addition.” “The temporal series of past events has been completed by successive addition.” ” The temporal series of past events cannot be an actual infinite.” Both arguments were adopted by Christian philosophers and theologians, and the second argument in particular became more famous after it was adopted by Immanuel Kant in his thesis of the first antinomyconcerning time.[60] Astronomical models[edit] Main article: History of astronomy Aristarchus’s 3rd century BCE calculations on the relative sizes of from left the Sun, Earth and Moon, from a 10th-century AD Greek copy Astronomical models of the Universe were proposed soon after astronomy began with the Babylonian astronomers, who viewed the Universe as a flat disk floating in the ocean, and this forms the premise for early Greek maps like those of Anaximander and Hecataeus of Miletus. Later Greek philosophers, observing the motions of the heavenly bodies, were concerned with developing models of the Universe based more profoundly on empirical evidence. The first coherent model was proposed by Eudoxus of Cnidos. According to Aristotle’s physical interpretation of the model, celestial spheres eternally rotate with uniform motion around a stationary Earth. Normal matter, is entirely contained within the terrestrial sphere. This model was also refined by Callippus and after concentric spheres were abandoned, it was brought into nearly perfect agreement with astronomical observations by Ptolemy. The success of such a model is largely due to the mathematical fact that any function (such as the position of a planet) can be decomposed into a set of circular functions (the Fourier modes). Other Greek scientists, such as the Pythagorean philosopher Philolaus postulated that at the center of the Universe was a “central fire” around which the Earth, Sun, Moon andPlanets revolved in uniform circular motion.[61] The Greek astronomer Aristarchus of Samos was the first known individual to propose a heliocentric model of the Universe. Though the original text has been lost, a reference in Archimedes’ book The Sand Reckoner describes Aristarchus’ heliocentric theory. Archimedes wrote: (translated into English) You King Gelon are aware the ‘Universe’ is the name given by most astronomers to the sphere the center of which is the center of the Earth, while its radius is equal to the straight line between the center of the Sun and the center of the Earth. This is the common account as you have heard from astronomers. But Aristarchus has brought out a book consisting of certain hypotheses, wherein it appears, as a consequence of the assumptions made, that the Universe is many times greater than the ‘Universe’ just mentioned. His hypotheses are that the fixed stars and the Sun remain unmoved, that the Earth revolves about the Sun on the circumference of a circle, the Sun lying in the middle of the orbit, and that the sphere of fixed stars, situated about the same center as the Sun, is so great that the circle in which he supposes the Earth to revolve bears such a proportion to the distance of the fixed stars as the center of the sphere bears to its surface. Aristarchus thus believed the stars to be very far away, and saw this as the reason why there was no parallax apparent, that is, no observed movement of the stars relative to each other as the Earth moved around the Sun. The stars are in fact much farther away than the distance that was generally assumed in ancient times, which is why stellar parallax is only detectable with precision instruments. The geocentric model, consistent with planetary parallax, was assumed to be an explanation for the unobservability of the parallel phenomenon, stellar parallax. The rejection of the heliocentric view was apparently quite strong, as the following passage from Plutarch suggests (On the Apparent Face in the Orb of the Moon): Cleanthes [a contemporary of Aristarchus and head of the Stoics] thought it was the duty of the Greeks to indict Aristarchus of Samos on the charge of impiety for putting in motion the Hearth of the Universe [i.e. the earth], . . . supposing the heaven to remain at rest and the earth to revolve in an oblique circle, while it rotates, at the same time, about its own axis. [1] The only other astronomer from antiquity known by name who supported Aristarchus’ heliocentric model was Seleucus of Seleucia, a Hellenistic astronomer who lived a century after Aristarchus.[62][63][64] According to Plutarch, Seleucus was the first to prove the heliocentric system through reasoning, but it is not known what arguments he used. Seleucus’ arguments for a heliocentric theory were probably related to the phenomenon of tides.[65] According to Strabo (1.1.9), Seleucus was the first to state that the tides are due to the attraction of the Moon, and that the height of the tides depends on the Moon’s position relative to the Sun.[66] Alternatively, he may have proved the heliocentric theory by determining the constants of a geometric model for the heliocentric theory and by developing methods to compute planetary positions using this model, like what Nicolaus Copernicus later did in the 16th century.[67] During the Middle Ages, heliocentric models may have also been proposed by the Indian astronomer, Aryabhata,[68]and by the Persian astronomers, Albumasar[69] and Al-Sijzi.[70] Model of the Copernican Universe byThomas Digges in 1576, with the amendment that the stars are no longer confined to a sphere, but spread uniformly throughout the space surrounding theplanets. The Aristotelian model was accepted in the Western world for roughly two millennia, until Copernicus revived Aristarchus’ theory that the astronomical data could be explained more plausibly if the earth rotated on its axis and if the sun were placed at the center of the Universe. “ In the center rests the sun. For who would place this lamp of a very beautiful temple in another or better place than this wherefrom it can illuminate everything at the same time? ” —Nicolaus Copernicus, in Chapter 10, Book 1 of De Revolutionibus Orbium Coelestrum (1543) As noted by Copernicus himself, the suggestion that the Earth rotates was very old, dating at least to Philolaus (c. 450 BC), Heraclides Ponticus (c. 350 BC) andEcphantus the Pythagorean. Roughly a century before Copernicus, Christian scholar Nicholas of Cusa also proposed that the Earth rotates on its axis in his book, On Learned Ignorance (1440).[71] Aryabhata (476–550), Brahmagupta (598–668), Albumasar and Al-Sijzi, also proposed that the Earth rotates on its axis.[citation needed]The first empirical evidence for the Earth’s rotation on its axis, using the phenomenon of comets, was given by Tusi (1201–1274) and Ali Qushji (1403–1474).[citation needed] Johannes Kepler published theRudolphine Tables containing a star catalog and planetary tables using Tycho Brahe’s measurements. This cosmology was accepted by Isaac Newton, Christiaan Huygens and later scientists.[72] Edmund Halley (1720)[73] andJean-Philippe de Cheseaux (1744)[74] noted independently that the assumption of an infinite space filled uniformly with stars would lead to the prediction that the nighttime sky would be as bright as the sun itself; this became known as Olbers’ paradox in the 19th century.[75] Newton believed that an infinite space uniformly filled with matter would cause infinite forces and instabilities causing the matter to be crushed inwards under its own gravity.[72] This instability was clarified in 1902 by the Jeans instability criterion.[76] One solution to these paradoxes is the Charlier Universe, in which the matter is arranged hierarchically (systems of orbiting bodies that are themselves orbiting in a larger system, ad infinitum) in a fractal way such that the Universe has a negligibly small overall density; such a cosmological model had also been proposed earlier in 1761 by Johann Heinrich Lambert.[36][77] A significant astronomical advance of the 18th century was the realization by Thomas Wright, Immanuel Kant and others ofnebulae.[73] The modern era of physical cosmology began in 1917, when Albert Einstein first applied his general theory of relativity to model the structure and dynamics of the Universe.[78] Theoretical models[edit] High-precision test of general relativity by the Cassini space probe (artist’s impression): radio signals sent between the Earth and the probe (green wave) aredelayed by the warping of space and time(blue lines) due to the Sun’s mass. Of the four fundamental interactions, gravitation is dominant at cosmological length scales; that is, the other three forces play a negligible role in determining structures at the level of planetary systems, galaxies and larger-scale structures. Because all matter and energy gravitate, gravity’s effects are cumulative; by contrast, the effects of positive and negative charges tend to cancel one another, making electromagnetism relatively insignificant on cosmological length scales. The remaining two interactions, the weak and strong nuclear forces, decline very rapidly with distance; their effects are confined mainly to sub-atomic length scales. General theory of relativity[edit] Main articles: Introduction to general relativity, General relativity, and Einstein’s field equations Given gravitation’s predominance in shaping cosmological structures, accurate predictions of the Universe’s pas and future require an accurate theory of gravitation. The best theory available is Albert Einstein’s general theory of relativity, which has passed all experimental tests to date. However, because rigorous experiments have not been carried out on cosmological length scales, general relativity could conceivably be inaccurate. Nevertheless, its cosmological predictions appear to be consistent with observations, so there is no compelling reason to adopt another theory. General relativity provides a set of ten nonlinear partial differential equations for the spacetime metric (Einstein’s field equations) that must be solved from the distribution of mass-energy and momentum throughout the Universe. Because these are unknown in exact detail, cosmological models have been based on thecosmological principle, which states that the Universe is homogeneous and isotropic. In effect, this principle asserts that the gravitational effects of the various galaxies making up the Universe are equivalent to those of a fine dust distributed uniformly throughout the Universe with the same average density. The assumption of a uniform dust makes it easy to solve Einstein’s field equations and predict the past and future of the Universe on cosmological time scales. Einstein’s field equations include a cosmological constant (Λ),[78][79] that corresponds to an energy density of empty space.[80] Depending on its sign, the cosmological constant can either slow (negative Λ) or accelerate (positive Λ) the expansion of the Universe. Although many scientists, including Einstein, had speculated that Λ was zero,[81] recent astronomical observations of type Ia supernovae have detected a large amount of “dark energy” that is accelerating the Universe’s expansion.[82] Preliminary studies suggest that this dark energy corresponds to a positive Λ, although alternative theories cannot be ruled out as yet.[83]Russian physicist Zel’dovich suggested that Λ is a measure of the zero-point energy associated with virtual particles of quantum field theory, a pervasive vacuum energy that exists everywhere, even in empty space.[84] Evidence for such zero-point energy is observed in the Casimir effect. Special relativity and space-time[edit] Main articles: Introduction to special relativity and Special relativity Only its length L is intrinsic to the rod (shown in black); coordinate differences between its endpoints (such as Δx, Δy or Δξ, Δη) depend on their frame of reference (depicted in blue and red, respectively). The Universe has at least three spatial and one temporal (time) dimension. It was long thought that the spatial and temporal dimensions were different in nature and independent of one another. However, according to the special theory of relativity, spatial and temporal separations are interconvertible (within limits) by changing one’s motion. To understand this interconversion, it is helpful to consider the analogous interconversion of spatial separations along the three spatial dimensions. Consider the two endpoints of a rod of length L. The length can be determined from the differences in the three coordinates Δx, Δy and Δz of the two endpoints in a given reference frame using the Pythagorean theorem. In a rotated reference frame, the coordinate differences differ, but they give the same length Thus, the coordinates differences (Δx, Δy, Δz) and (Δξ, Δη, Δζ) are not intrinsic to the rod, but merely reflect the reference frame used to describe it; by contrast, the length L is an intrinsic property of the rod. The coordinate differences can be changed without affecting the rod, by rotating one’s reference frame. The analogy in spacetime is called the interval between two events; an event is defined as a point in spacetime, a specific position in space and a specific moment in time. The spacetime interval between two events is given by where c is the speed of light. According to special relativity, one can change a spatial and time separation (L1, Δt1) into another (L2, Δt2) by changing one’s reference frame, as long as the change maintains the spacetime interval s. Such a change in reference frame corresponds to changing one’s motion; in a moving frame, lengths and times are different from their counterparts in a stationary reference frame. The precise manner in which the coordinate and time differences change with motion is described by the Lorentz transformation. Solving Einstein’s field equations[edit] See also: Big Bang and Ultimate fate of the Universe Animation illustrating the metric expansion of the universe The distances between the spinning galaxies increase with time, but the distances between the stars within each galaxy stay roughly the same, due to their gravitational interactions. This animation illustrates a closed Friedmann Universe with zero cosmological constant Λ; such a Universe oscillates between a Big Bangand a Big Crunch. In non-Cartesian (non-square) or curved coordinate systems, the Pythagorean theorem holds only on infinitesimal length scales and must be augmented with a more general metric tensor gμν, which can vary from place to place and which describes the local geometry in the particular coordinate system. However, assuming thecosmological principle that the Universe is homogeneous and isotropic everywhere, every point in space is like every other point; hence, the metric tensor must be the same everywhere. That leads to a single form for the metric tensor, called the Friedmann–Lemaître–Robertson–Walker metric where (r, θ, φ) correspond to a spherical coordinate system. This metric has only two undetermined parameters: an overall length scale R that can vary with time, and a curvature index k that can be only 0, 1 or −1, corresponding to flat Euclidean geometry, or spaces of positive or negative curvature. In cosmology, solving for the history of the Universe is done by calculating R as a function of time, given k and the value of the cosmological constant Λ, which is a (small) parameter in Einstein’s field equations. The equation describing how R varies with time is known as the Friedmann equation, after its inventor, Alexander Friedmann.[85] The solutions for R(t) depend on k and Λ, but some qualitative features of such solutions are general. First and most importantly, the length scale R of the Universe can remain constant only if the Universe is perfectly isotropic with positive curvature (k=1) and has one precise value of density everywhere, as first noted by Albert Einstein. However, this equilibrium is unstable and because the Universe is known to be inhomogeneous on smaller scales, R must change, according to general relativity. When R changes, all the spatial distances in the Universe change in tandem; there is an overall expansion or contraction of space itself. This accounts for the observation that galaxies appear to be flying apart; the space between them is stretching. The stretching of space also accounts for the apparent paradox that two galaxies can be 40 billion light years apart, although they started from the same point 13.8 billion years ago[86] and never moved faster than the speed of light. Second, all solutions suggest that there was a gravitational singularity in the past, when R goes to zero and matter and energy became infinitely dense. It may seem that this conclusion is uncertain because it is based on the questionable assumptions of perfect homogeneity and isotropy (the cosmological principle) and that only the gravitational interaction is significant. However, the Penrose–Hawking singularity theorems show that a singularity should exist for very general conditions. Hence, according to Einstein’s field equations, R grew rapidly from an unimaginably hot, dense state that existed immediately following this singularity (when R had a small, finite value); this is the essence of the Big Bang model of the Universe. A common misconception is that the Ba Space has no boundary – that is empirically more certain than any external observation. However, that does not imply that space is infinite… (translated, original German) Bernhard Riemann (Habilitationsvortrag, 1854) ng model predicts that matter and energy exploded from a single point in space and time; that is false. Rather, space itself was created in the Big Bang and imbued with a fixed amount of energy and matter distributed uniformly throughout; as space expands (i.e., asR(t) increases), the density of thatmatter and energy decreases. Third, the curvature index k determines the sign of the mean spatial curvature of spacetime averaged over length scales greater than a billion light years. If k=1, the curvature is positive and the Universe has a finite volume. Such universes are often visualized as a three-dimensional sphere S3embedded in a four-dimensional space. Conversely, if k is zero or negative, the Universe may have infinite volume, depending on its overalltopology. It may seem counter-intuitive that an infinite and yet infinitely dense Universe could be created in a single instant at the Big Bang whenR=0, but exactly that is predicted mathematically when k does not equal 1. For comparison, an infinite plane has zero curvature but infinite area, whereas an infinite cylinder is finite in one direction and a torus is finite in both. A toroidal Universe could behave like a normal Universe withperiodic boundary conditions, as seen in “wrap-around” video games such as Asteroids; a traveler crossing an outer “boundary” of space going outwards would reappear instantly at another point on the boundary moving inwards. Illustration of the Big Bang theory, the prevailing model of the origin and expansion of spacetime and all that it contains. In this diagram time increases from left to right, and one dimension of space is suppressed, so at any given time the Universe is represented by a disk-shaped “slice” of the diagram. The ultimate fate of the Universe is still unknown, because it depends critically on the curvature index k and the cosmological constant Λ. If the Universe is sufficiently dense, k equals +1, meaning that its average curvature throughout is positive and the Universe will eventually recollapse in a Big Crunch, possibly starting a new Universe in a Big Bounce. Conversely, if the Universe is insufficiently dense, kequals 0 or −1 and the Universe will expand forever, cooling off and eventually becoming inhospitable for all life, as the stars die and all matter coalesces into black holes (the Big Freeze and the heat death of the Universe). As noted above, recent data suggests that the expansion speed of the Universe is not decreasing as originally expected, but increasing; if this continues indefinitely, the Universe will eventually rip itself to shreds (the Big Rip). Experimentally, the Universe has an overall density that is very close to the critical value between recollapse and eternal expansion; more careful astronomical observations are needed to resolve the question. Big Bang model[edit] Main articles: Big Bang, Timeline of the Big Bang, Nucleosynthesis, and Lambda-CDM model The prevailing Big Bang model accounts for many of the experimental observations described above, such as the correlation of distance and redshift of galaxies, the universal ratio of hydrogen:helium atoms, and the ubiquitous, isotropic microwave radiation background. As noted above, the redshift arises from the metric expansion of space; as the space itself expands, the wavelength of a photon traveling through space likewise increases, decreasing its energy. The longer a photon has been traveling, the more expansion it has undergone; hence, older photons from more distant galaxies are the most red-shifted. Determining the correlation between distance and redshift is an important problem in experimental physical cosmology. Chief nuclear reactions responsible for the relative abundances of light atomic nuclei observed throughout the Universe. Other experimental observations can be explained by combining the overall expansion of space with nuclear and atomic physics. As the Universe expands, the energy density of the electromagnetic radiation decreases more quickly than does that of matter, because the energy of a photon decreases with its wavelength. Thus, although the energy density of the Universe is now dominated by matter, it was once dominated by radiation; poetically speaking, all was light. As the Universe expanded, its energy density decreased and it became cooler; as it did so, the elementary particles of matter could associate stably into ever larger combinations. Thus, in the early part of the matter-dominated era, stable protons and neutrons formed, which then associated into atomic nuclei. At this stage, the matter in the Universe was mainly a hot, dense plasma of negative electrons, neutral neutrinos and positive nuclei. Nuclear reactionsamong the nuclei led to the present abundances of the lighter nuclei, particularly hydrogen, deuterium, and helium. Eventually, the electrons and nuclei combined to form stable atoms, which are transparent to most wavelengths of radiation; at this point, the radiation decoupled from the matter, forming the ubiquitous, isotropic background of microwave radiation observed today. Other observations are not answered definitively by known physics. According to the prevailing theory, a slight imbalance of matter overantimatter was present in the Universe’s creation, or developed very shortly thereafter, possibly due to the CP violation that has been observed by particle physicists. Although the matter and antimatter mostly annihilated one another, producing photons, a small residue of matter survived, giving the present matter-dominated Universe. Several lines of evidence also suggest that a rapid cosmic inflation of the Universe occurred very early in its history (roughly 10−35 seconds after its creation). Recent observations also suggest that the cosmological constant (Λ) is not zero and that the net mass-energy content of the Universe is dominated by a dark energy and dark matter that have not been characterized scientifically. They differ in their gravitational effects. Dark matter gravitates as ordinary matter does, and thus slows the expansion of the Universe; by contrast, dark energy serves to accelerate the Universe’s expansion. Multiverse theory[edit] Main articles: Multiverse, Many-worlds interpretation, Bubble universe theory, and Parallel universe (fiction) Depiction of a multiverse of seven”bubble” universes, which are separatespacetime continua, each having differentphysical laws, physical constants, and perhaps even different numbers ofdimensions or topologies. Some speculative theories have proposed that this Universe is but one of a set of disconnected universes, collectively denoted as the multiverse, challenging or enhancing more limited definitions of the Universe.[34][87] Scientific multiverse theories are distinct from concepts such as alternate planes of consciousness andsimulated reality, although the idea of a larger Universe is not new; for example, Bishop Étienne Tempier of Paris ruled in 1277 that God could create as many universes as he saw fit, a question that was being hotly debated by the French theologians.[88] Max Tegmark developed a four-part classification scheme for the different types of multiverses that scientists have suggested in various problem domains. An example of such a theory is the chaotic inflation model of the early Universe.[89] Another is the many-worlds interpretation of quantum mechanics. Parallel worlds are generated in a manner similar to quantum superposition and decoherence, with all states of the wave function being realized in separate worlds. Effectively, the multiverse evolves as a universal wavefunction. If the big bang that created our multiverse created an ensemble of multiverses, the wave function of the ensemble would be entangled in this sense. The least controversial category of multiverse in Tegmark’s scheme is Level I, which describes distant space-time events “in our own Universe”. If space is infinite, or sufficiently large and uniform, identical instances of the history of Earth’s entire Hubble volume occur every so often, simply by chance. Tegmark calculated our nearest so-called doppelgänger, is 1010115 meters away from us (a double exponential function larger than a googolplex).[90][91] In principle, it would be impossible to scientifically verify an identical Hubble volume. However, it does follow as a fairly straightforward consequence from otherwise unrelated scientific observations and theories. Tegmark suggests that statistical analysis exploiting the anthropic principle provides an opportunity to test multiverse theories in some cases. Generally, science would consider a multiverse theory that posits neither a common point of causation, nor the possibility of interaction between universes, to be an idle speculation. Shape of the Universe[edit] Main article: Shape of the Universe The shape or geometry of the Universe includes both local geometry in the observable Universe and global geometry, which we may or may not be able to measure. Shape can refer to curvature and topology. More formally, the subject in practice investigates which 3-manifold corresponds to the spatial section in comoving coordinates of the four- dimensional space-time of the Universe. Cosmologists normally work with a given space-like slice of spacetime called the comoving coordinates. In terms of observation, the section of spacetime that can be observed is the backward light cone (points within the cosmic light horizon, given time to reach a given observer). If the observable Universe is smaller than the entire Universe (in some models it is many orders of magnitude smaller), one cannot determine the global structure by observation: one is limited to a small patch. Among the Friedmann–Lemaître–Robertson–Walker (FLRW) models, the presently most popular shape of the Universe found to fit observational data according to cosmologists is the infinite flat model,[92] while other FLRW models include the Poincaré dodecahedral space[93][94] and the Picard horn.[95] The data fit by these FLRW models of space especially include the Wilkinson Microwave Anisotropy Probe (WMAP) and Planck maps of cosmic background radiation. NASA released the first WMAP cosmic background radiation data in February 2003, while a higher resolution map regarding Planck data was released by ESA in March 2013. Both probes have found almost perfect agreement with inflationary models and the standard model of cosmology, describing a flat, homogenous universe dominated by dark matter and dark energy.[9][96] See also[edit] Astronomy portal Space portal • Religious cosmology • Cosmic latte • Cosmology • Hindu cosmology • Dyson’s eternal intelligence • Esoteric cosmology • False vacuum • Final anthropic principle • Fine-tuned Universe • Hindu cycle of the universe • Jain cosmology • Kardashev scale • The Mysterious Universe (book) • Nucleocosmochronology • Non-standard cosmology • Observable universe • Omega Point • Rare Earth hypothesis • Vacuum genesis • World view • Zero-energy Universe Notes and references[edit] 1. Jump up^ “Universe”. Webster’s New World College Dictionary, Wiley Publishing, Inc. 2010. 2. Jump up^ “Universe”. 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Edward (2005). “First Determination of the Distance and Fundamental Properties of an Eclipsing Binary in the Andromeda Galaxy”.Astrophysical Journal 635 (1): L37–L40. arXiv:astro-ph/0511045. Bibcode:2005ApJ…635L..37R.doi:10.1086/499161. McConnachie, A. W.; Irwin, M. J.; Ferguson, A. M. N.; Ibata, R. A.; Lewis, G. F.; Tanvir, N. (2005). “Distances and metallicities for 17 Local Group galaxies”. Monthly Notices of the Royal Astronomical Society 356 (4): 979–997. arXiv:astro-ph/0410489. Bibcode:2005MNRAS.356..979M.doi:10.1111/j.1365-2966.2004.08514.x. 39. Jump up^ Mackie, Glen (February 1, 2002). “To see the Universe in a Grain of Taranaki Sand”. Swinburne University. Retrieved 2006-12-20. 40. Jump up^ “Unveiling the Secret of a Virgo Dwarf Galaxy”. ESO. 2000-05-03. Retrieved 2007-01-03. 41. Jump up^ “Hubble’s Largest Galaxy Portrait Offers a New High-Definition View”. NASA. 2006-02-28. Retrieved 2007-01-03. 42. Jump up^ Vergano, Dan (1 December 2010). “Universe holds billions more stars than previously thought”.USA Today. Retrieved 2010-12-14. 43. Jump up^ Mandolesi, N.; Calzolari, P.; Cortiglioni, S.; Delpino, F.; Sironi, G.; Inzani, P.; Deamici, G.; Solheim, J. -E.; Berger, L.; Partridge, R. B.; Martenis, P. L.; Sangree, C. H.; Harvey, R. C. (1986). “Large-scale homogeneity of the Universe measured by the microwave background”. Nature 319 (6056): 751.doi:10.1038/319751a0. edit 44. Jump up^ Hinshaw, Gary (November 29, 2006). “New Three Year Results on the Oldest Light in the Universe”. NASA WMAP. Retrieved 2006-08-10. 45. Jump up^ Hinshaw, Gary (December 15, 2005). “Tests of the Big Bang: The CMB”. NASA WMAP. Retrieved 2007-01-09. 46. Jump up^ Rindler, p. 202. 47. Jump up^ Hinshaw, Gary (February 10, 2006). “What is the Universe Made Of?”. NASA WMAP. Retrieved 2007-01-04. 48. Jump up^ Wright, Edward L. (September 12, 2004). “Big Bang Nucleosynthesis”. UCLA. Retrieved 2007-01-05. M. Harwit, M. Spaans (2003). “Chemical Composition of the Early Universe”. The Astrophysical Journal589 (1): 53–57. arXiv:astro-ph/0302259. Bibcode:2003ApJ…589…53H. doi:10.1086/374415. C. Kobulnicky, E. D. Skillman; Skillman (1997). “Chemical Composition of the Early Universe”. Bulletin of the American Astronomical Society 29: 1329. Bibcode:1997AAS…191.7603K. 49. Jump up^ “Antimatter”. Particle Physics and Astronomy Research Council. October 28, 2003. Retrieved 2006-08-10. 50. Jump up^ Landau and Lifshitz, p. 361. 51. Jump up^ WMAP Mission: Results – Age of the Universe. Map.gsfc.nasa.gov. Retrieved 2011-11-28. 52. Jump up^ Luminet, Jean-Pierre; Boudewijn F. Roukema (1999). “Topology of the Universe: Theory and Observations”. Proceedings of Cosmology School held at Cargese, Corsica, August 1998. arXiv:astro-ph/9901364. Luminet, Jean-Pierre; J. Weeks, A. Riazuelo, R. Lehoucq, J.-P. Uzan (2003). “Dodecahedral space topology as an explanation for weak wide-angle temperature correlations in the cosmic microwave background”. Nature 425 (6958): 593–595. arXiv:astro-ph/0310253. Bibcode:2003Natur.425..593L.doi:10.1038/nature01944. PMID 14534579. 53. Jump up^ Strobel, Nick (May 23, 2001). “The Composition of Stars”. Astronomy Notes. Retrieved 2007-01-04. “Have physical constants changed with time?”. Astrophysics (Astronomy Frequently Asked Questions). Retrieved 2007-01-04. 54. Jump up^ Rees, Martin (1999). Just Six Numbers. HarperCollins Publishers. ISBN 0-465-03672-4. 55. Jump up^ Adams, F.C. (2008). “Stars in other universes: stellar structure with different fundamental constants”.Journal of Cosmology and Astroparticle Physics 2008 (8): 010. arXiv:0807.3697.Bibcode:2008JCAP…08..010A. doi:10.1088/1475-7516/2008/08/010. 56. Jump up^ Harnik, R.; Kribs, G.D. and Perez, G. (2006). “A Universe without weak interactions”. Physical Review D 74 (3): 035006. arXiv:hep-ph/0604027. Bibcode:2006PhRvD..74c5006H.doi:10.1103/PhysRevD.74.035006. 57. Jump up^ (Henry Gravrand, “La civilisation Sereer -Pangool”) [in] Universität Frankfurt am Main, Frobenius-Institut, Deutsche Gesellschaft für Kulturmorphologie, Frobenius Gesellschaft, “Paideuma: Mitteilungen zur Kulturkunde, Volumes 43–44”, F. Steiner (1997), pp. 144–5, ISBN 3515028420 58. Jump up^ Will Durant, Our Oriental Heritage: “Two systems of Hindu thought propound physical theories suggestively similar to those of Greece. Kanada, founder of the Vaisheshika philosophy, held that the world was composed of atoms as many in kind as the various elements. The Jains more nearly approximated to Democritus by teaching that all atoms were of the same kind, producing different effects by diverse modes of combinations. Kanada believed light and heat to be varieties of the same substance; Udayana taught that all heat comes from the sun; andVachaspati, like Newton, interpreted light as composed of minute particles emitted by substances and striking the eye.” 59. Jump up^ Stcherbatsky, F. Th. (1930, 1962), Buddhist Logic, Volume 1, p. 19, Dover, New York: “The Buddhists denied the existence of substantial matter altogether. Movement consists for them of moments, it is a staccato movement, momentary flashes of a stream of energy… “Everything is evanescent“,… says the Buddhist, because there is no stuff… Both systems [Sānkhya, and later Indian Buddhism] share in common a tendency to push the analysis of existence up to its minutest, last elements which are imagined as absolute qualities, or things possessing only one unique quality. They are called “qualities” (guna-dharma) in both systems in the sense of absolute qualities, a kind of atomic, or intra-atomic, energies of which the empirical things are composed. Both systems, therefore, agree in denying the objective reality of the categories of Substance and Quality,… and of the relation of Inference uniting them. There is in Sānkhya philosophy no separate existence of qualities. What we call quality is but a particular manifestation of a subtle entity. To every new unit of quality corresponds a subtle quantum of matter which is called guna “quality”, but represents a subtle substantive entity. The same applies to early Buddhism where all qualities are substantive… or, more precisely, dynamic entities, although they are also called dharmas (‘qualities’).” 60. ^ Jump up to:a b c Craig, William Lane (June 1979). “Whitrow and Popper on the Impossibility of an Infinite Past”.The British Journal for the Philosophy of Science 30 (2): 165–170 (165–6). doi:10.1093/bjps/30.2.165. 61. Jump up^ Boyer, C. (1968) A History of Mathematics. Wiley, p. 54. 62. Jump up^ Neugebauer, Otto E. (1945). “The History of Ancient Astronomy Problems and Methods”. Journal of Near Eastern Studies 4 (1): 1–38. doi:10.1086/370729. JSTOR 595168. “the Chaldaean Seleucus from Seleucia” 63. Jump up^ Sarton, George (1955). “Chaldaean Astronomy of the Last Three Centuries B. C”. Journal of the American Oriental Society 75 (3): 166–173 (169). doi:10.2307/595168. JSTOR 595168. “the heliocentrical astronomy invented by Aristarchos of Samos and still defended a century later by Seleucos the Babylonian” 64. Jump up^ William P. D. Wightman (1951, 1953), The Growth of Scientific Ideas, Yale University Press p. 38, where Wightman calls him Seleukos the Chaldean. 65. Jump up^ Lucio Russo, Flussi e riflussi, Feltrinelli, Milano, 2003, ISBN 88-07-10349-4. 66. Jump up^ Bartel, p. 527 67. Jump up^ Bartel, pp. 527–9 68. Jump up^ Bartel, pp. 529–34 69. Jump up^ Bartel, pp. 534–7 70. Jump up^ Nasr, Seyyed H. (1st edition in 1964, 2nd edition in 1993). An Introduction to Islamic Cosmological Doctrines (2nd ed.). 1st edition by Harvard University Press, 2nd edition by State University of New York Press. pp. 135–6. ISBN 0-7914-1515-5. 71. Jump up^ Misner, Thorne and Wheeler, p. 754. 72. ^ Jump up to:a b Misner, Thorne and Wheeler, p. 755–756. 73. ^ Jump up to:a b Misner, Thorne and Wheeler, p. 756. 74. Jump up^ de Cheseaux JPL (1744). Traité de la Comète. Lausanne. pp. 223ff.. Reprinted as Appendix II inDickson FP (1969). The Bowl of Night: The Physical Universe and Scientific Thought. Cambridge, MA: M.I.T. Press. ISBN 978-0-262-54003-2. 75. Jump up^ Olbers HWM (1826). “Unknown title”. Bode’s Jahrbuch 111.. Reprinted as Appendix I in Dickson FP (1969). The Bowl of Night: The Physical Universe and Scientific Thought. Cambridge, MA: M.I.T. Press.ISBN 978-0-262-54003-2. 76. Jump up^ Jeans, J. H. (1902). “The Stability of a Spherical Nebula” (PDF). Philosophical Transactions of the Royal Society A 199 (312–320): 1–53. Bibcode:1902RSPTA.199….1J. doi:10.1098/rsta.1902.0012.JSTOR 90845. Retrieved 2011-03-17. 77. Jump up^ Misner, Thorne and Wheeler, p. 757. 78. ^ Jump up to:a b Einstein, A (1917). “Kosmologische Betrachtungen zur allgemeinen Relativitätstheorie”.Preussische Akademie der Wissenschaften, Sitzungsberichte. 1917. (part 1): 142–152. 79. Jump up^ Rindler, pp. 226–229. 80. Jump up^ Landau and Lifshitz, pp. 358–359. 81. Jump up^ Einstein, A (1931). “Zum kosmologischen Problem der allgemeinen Relativitätstheorie”.Sitzungsberichte der Preussischen Akademie der Wissenschaften, Physikalisch-mathematische Klasse1931: 235–237. Einstein A., de Sitter W. (1932). “On the relation between the expansion and the mean density of the Universe”. Proceedings of the National Academy of Sciences 18 (3): 213–214.Bibcode:1932PNAS…18..213E. doi:10.1073/pnas.18.3.213. PMC 1076193. PMID 16587663. 82. Jump up^ Hubble Telescope news release. Hubblesite.org (2004-02-20). Retrieved 2011-11-28. 83. Jump up^ “Mysterious force’s long presence”. BBC News. 2006-11-16. 84. Jump up^ Zel’dovich YB (1967). “Cosmological constant and elementary particles”. JETP Letters 6: 316–317.Bibcode:1967JETPL…6..316Z. 85. Jump up^ Friedmann A. (1922). “Über die Krümmung des Raumes”. Zeitschrift für Physik 10 (1): 377–386.Bibcode:1922ZPhy…10..377F. doi:10.1007/BF01332580. 86. Jump up^ “Cosmic Detectives”. The European Space Agency (ESA). 2013-04-02. Retrieved 2013-04-15. 87. Jump up^ Munitz MK (1959). “One Universe or Many?”. Journal of the History of Ideas 12 (2): 231–255.doi:10.2307/2707516. JSTOR 2707516. 88. Jump up^ Misner, Thorne and Wheeler, p. 753. 89. Jump up^ Linde A. (1986). “Eternal chaotic inflation”. Mod. Phys. Lett. A1 (2): 81–85.Bibcode:1986MPLA….1…81L. doi:10.1142/S0217732386000129. Linde A. (1986). “Eternally existing self-reproducing chaotic inflationary Universe” (PDF). Phys. Lett.B175 (4): 395–400. Bibcode:1986PhLB..175..395L. doi:10.1016/0370-2693(86)90611-8. Retrieved 2011-03-17. 90. Jump up^ Tegmark M. (2003). “Parallel universes. Not just a staple of science fiction, other universes are a direct implication of cosmological observations”. Scientific American 288 (5): 40–51.doi:10.1038/scientificamerican0503-40. PMID 12701329. 91. Jump up^ Tegmark, Max (2003). “Parallel Universes”. In “Science and Ultimate Reality: from Quantum to Cosmos”, honoring John Wheeler’s 90th birthday. J. D. Barrow, P.C.W. Davies, & C.L. Harper eds. Cambridge University Press (2003): 2131. arXiv:astro-ph/0302131. Bibcode:2003astro.ph..2131T. 92. Jump up^ Will the Universe expand forever?, WMAP website at NASA. 93. Jump up^ Luminet, Jean-Pierre; Jeff Weeks, Alain Riazuelo, Roland Lehoucq, Jean-Phillipe Uzan (2003-10-09). “Dodecahedral space topology as an explanation for weak wide-angle temperature correlations in the cosmic microwave background”. Nature 425 (6958): 593–5. arXiv:astro-ph/0310253.Bibcode:2003Natur.425..593L. doi:10.1038/nature01944. PMID 14534579. 94. Jump up^ Roukema, Boudewijn; Zbigniew Buliński, Agnieszka Szaniewska, Nicolas E. Gaudin (2008). “A test of the Poincare dodecahedral space topology hypothesis with the WMAP CMB data”. Astronomy and Astrophysics 482 (3): 747. arXiv:0801.0006. Bibcode:2008A&A…482..747L. doi:10.1051/0004-6361:20078777. 95. Jump up^ Aurich, Ralf; Lustig, S., Steiner, F., Then, H. (2004). “Hyperbolic Universes with a Horned Topology and the CMB Anisotropy”. Classical and Quantum Gravity 21 (21): 4901–4926. arXiv:astro-ph/0403597. Bibcode:2004CQGra..21.4901A. doi:10.1088/0264-9381/21/21/010. 96. Jump up^ “Planck reveals ‘almost perfect’ universe”. Michael Banks. Physics World. 2013-03-21. Retrieved 2013-03-21. Bibliography[edit] • Bartel (1987). “The Heliocentric System in Greek, Persian and Hindu Astronomy”. Annals of the New York Academy of Sciences 500 (1): 525–545. Bibcode:1987NYASA.500..525V. doi:10.1111/j.1749-6632.1987.tb37224.x. • Landau, Lev, Lifshitz, E.M. (1975). The Classical Theory of Fields (Course of Theoretical Physics, Vol. 2) (revised 4th English ed.). New York: Pergamon Press. pp. 358–397. ISBN 978-0-08-018176-9. • Liddell, H. G. and Scott, R. A Greek-English Lexicon. Oxford University Press. ISBN 0-19-864214-8. • Misner, C.W., Thorne, Kip, Wheeler, J.A. (1973). Gravitation. San Francisco: W. H. Freeman. pp. 703–816. ISBN 978-0-7167-0344-0. • Rindler, W. (1977). Essential Relativity: Special, General, and Cosmological. New York: Springer Verlag. pp. 193–244. ISBN 0-387-10090-3. Further reading[edit] • Weinberg, S. (1993). The First Three Minutes: A Modern View of the Origin of the Universe (2nd updated ed.). New York: Basic Books. ISBN 978-0-465-02437-7. OCLC 28746057. For lay readers. • Nussbaumer, Harry; Bieri, Lydia; Sandage, Allan (2009). Discovering the Expanding Universe. Cambridge University Press. ISBN 978-0-521-51484-2. External links[edit] Wikimedia Commons has media related to Universe. Wikiquote has a collection of quotations related to: Universe • Is there a hole in the Universe? at HowStuffWorks • Stephen Hawking’s Universe – Why is the Universe the way it is? • Cosmology FAQ • Cosmos – An “illustrated dimensional journey from microcosmos to macrocosmos” • Illustration comparing the sizes of the planets, the sun, and other stars • My So-Called Universe – Arguments for and against an infinite and parallel universes • The Dark Side and the Bright Side of the Universe Princeton University, Shirley Ho • Richard Powell: An Atlas of the Universe – Images at various scales, with explanations • Multiple Big Bangs • Universe – Space Information Centre Listen to this article (4 parts) · (info) Part 1 • Part 2 • Part 3 • Part 4 This audio file was created from a revision of the “Universe” article dated 2012-06-13, and does not reflect subsequent edits to the article. (Audio help) More spoken articles Videos[edit] • Cosmography of the Local Universe at irfu.cea.fr (17:35) (arXiv) • The Known Universe created by the American Museum of Natural History • Understand The Size Of The Universe – by Powers of Ten • 3-D Video (01:46) – Over a Million Galaxies of Billions of Stars each – BerkeleyLab/animated • The Future of the Universe – NASAHome/News [show] • V • T • E Earth’s location in the universe [show] • V • T • E Elements of nature Categories: • Environments • Physical cosmology • Places • Universe Our Body Human body From Wikipedia, the free encyclopedia This article needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. (November 2013) Human body Human body features displayed on bodies on which body hair and male facial hair has been removed The human body is the entire structure of a human organism and comprises a head, neck, torso, two arms and two legs. By the time the human reaches adulthood, the body consists of close to 100 trillion cells,[1] the basic unit of life.[2] These cells are organised biologically to eventually form the whole body. Contents [hide] • 1 Structure o 1.1 Size o 1.2 Human anatomy • 1.2.1 Anatomical variations o 1.3 Human physiology o 1.4 Systems o 1.5 Homeostasis • 2 Society and culture o 2.1 Depiction o 2.2 Appearance o 2.3 History of anatomy o 2.4 History of physiology • 3 See also • 4 Further reading o 4.1 References • 5 External links Structure[edit] Further information: Anatomy, Body proportion, and Anatomical terminology Constituents of the human body In a normal man weighing 60 kg Constituent Weight[3] Percent of atoms[3] Hydrogen 6.0 kg 63% Oxygen 38.8 kg 25.5% Carbon 10.9 kg 9.5% Nitrogen 1.9 kg 1.4% Calcium 1.2 kg 2.0% Phosphorus 0.6 kg 0.2% Potassium 0.2 kg 0.07% Size[edit] The average height of an adult male human (in developed countries) is about 1.7–1.8 m (5’7″ to 5’11”) tall and the adult female is about 1.6–1.7 m (5’2″ to 5’7″) tall.[4] Height is largely determined by genes and diet. Body type and composition are influenced by factors such as genetics, diet, and exercise. Human anatomy[edit] Further information: Body shape and Female body shape Anatomical study by Leonardo da Vinci Human anatomy (gr. ἀνατομία, “dissection”, from ἀνά, “up”, and τέμνειν, “cut”) is primarily the scientific study of the morphology of the human body.[5] Anatomy is subdivided into gross anatomy and microscopic anatomy.[5] Gross anatomy (also called topographical anatomy, regional anatomy, or anthropotomy) is the study of anatomical structures that can be seen by the naked eye.[5] Microscopic anatomy is the study of minute anatomical structures assisted with microscopes, which includes histology (the study of the organization of tissues),[5] and cytology (the study of cells). Anatomy, human physiology (the study of function), and biochemistry (the study of the chemistry of living structures) are complementary basic medical sciences that are generally together (or in tandem) to students studying medical sciences. In some of its facets human anatomy is closely related to embryology, comparative anatomy and comparative embryology,[5] through common roots in evolution; for example, much of the human body maintains the ancient segmental pattern that is present in all vertebrates with basic units being repeated, which is particularly obvious in the vertebral column and in the ribcage, and can be traced from very early embryos. Generally, physicians, dentists, physiotherapists, nurses, paramedics, radiographers, and students of certain biological sciences, learn gross anatomy and microscopic anatomy from anatomical models, skeletons, textbooks, diagrams, photographs, lectures, and tutorials. The study of microscopic anatomy (or histology) can be aided by practical experience examining histological preparations (or slides) under a microscope; and in addition, medical and dental students generally also learn anatomy with practical experience of dissection and inspection of cadavers (dead human bodies). A thorough working knowledge of anatomy is required for all medical doctors, especially surgeons, and doctors working in some diagnostic specialities, such as histopathology and radiology. Human anatomy, physiology, and biochemistry are basic medical sciences, which are generally taught to medical students in their first year at medical school. Human anatomy can be taught regionally or systemically;[5] that is, respectively, studying anatomy by bodily regions such as the head and chest, or studying by specific systems, such as the nervous or respiratory systems. The major anatomy textbook, Gray’s Anatomy, has recently been reorganized from a systems format to a regional format, in line with modern teaching.[6][7] Anatomical variations[edit] Further information: List of anatomical variations This section does not cite any references or sources. Please help improve this section by adding citations to reliable sources. Unsourced material may be challenged and removed. (June 2012) In human anatomy, the term anatomical variation refers to a non-pathologic anatomic structure that is different from what is observed in most people. The possible anatomic variations in each organ and its arterial and venous supply must be known by physicians, such as surgeons or radiologists, in order to correctly identify those structures. Unlike congenital anomalies, anatomic variations are considered normal and do not constitute a disorder. Human physiology[edit] Main article: Physiology Human physiology is the science of the mechanical, physical, bioelectrical, and biochemical functions of humans in good health, their organs, and the cells of which they are composed. Physiology focuses principally at the level of organs and systems. Most aspects of human physiology are closely homologous to corresponding aspects of animal physiology, and animal experimentation has provided much of the foundation of physiological knowledge. Anatomy and physiology are closely related fields of study: anatomy, the study of form, and physiology, the study of function, are intrinsically related and are studied in tandem as part of a medical curriculum. Systems[edit] • • Traditionally, the academic discipline of physiology views the body as a collection of interacting systems, each with its own combination of functions and purposes. Each body system contributes to the homeostasis of other systems and of the entire organism. No system of the body works in isolation, and the well-being of the person depends upon the well-being of all the interacting body systems. System Clinical study Physiology, etc. The nervous system consists of the central nervous system (which is the brain and spinal cord) and peripheral nervous system. The brain is the organ of thought, emotion, memory, and sensory processing, and serves many aspects of communication and control of various other systems and functions. The special senses consist of vision, hearing, taste, andsmell. The eyes, ears, tongue, and nose gather information about the body’s environment. neuroscience, neurology(disease), psychiatry(behavioral), ophthalmology(vision), otolaryngology(hearing, taste, smell) neurophysiology The musculoskeletal system consists of the human skeleton (which includes bones, ligaments, tendons, and cartilage) and attached muscles. It gives the body basic structure and the ability for movement. In addition to their structural role, the larger bones in the body contain bone marrow, the site of production of blood cells. Also, all bones are major storage sites forcalcium and phosphate. This system can be split up into the muscular system and the skeletal system. orthopedics (bone and muscle disorders and injuries) cell physiology, musculoskeletal physiology, osteology (skeleton) The circulatory system or cardiovascular system comprises the heart and blood vessels (arteries, veins, capillaries). The heart propels the circulation of the blood, which serves as a “transportation system” to transfer oxygen, fuel, nutrients, waste products, immune cells, and signalling molecules (i.e., hormones) from one part of the body to another. The blood consists of fluid that carries cells in the circulation, including some that move from tissue to blood vessels and back, as well as thespleen and bone marrow. cardiology (heart),hematology (blood) cardiovascular physiology[8][9] The heart itself is divided into three layers called theendocardium, myocardium and epicardium,(liquidation) which vary in thickness and function.[10] The respiratory system consists of the nose, nasopharynx, trachea, and lungs. It brings oxygen from the air and excretescarbon dioxide and water back into the air. pulmonology respiratory physiology The gastrointestinal system consists of the mouth, esophagus, stomach, gut (small and large intestines), and rectum, as well as the liver, pancreas, gallbladder, and salivary glands. It converts food into small, nutritional, non-toxic molecules for distribution by the circulation to all tissues of the body, and excretes the unused residue. gastroenterology gastrointestinal physiology The integumentary system consists of the covering of the body (the skin), including hair and nails as well as other functionally important structures such as the sweat glands and sebaceous glands. The skin provides containment, structure, and protection for other organs, but it also serves as a major sensory interface with the outside world. dermatology cell physiology, skin physiology The urinary system consists of the kidneys, ureters, bladder, and urethra. It removes water from the blood to produce urine, which carries a variety of waste molecules and excess ions and water out of the body. nephrology (function),urology (structural disease) renal physiology The reproductive system consists of the gonads and the internal and external sex organs. The reproductive system produces gametes in each sex, a mechanism for their combination, and a nurturing environment for the first 9 months of development of the infant. gynecology (women),andrology (men), sexology(behavioral aspects)embryology (developmental aspects) reproductive physiology The immune system consists of the white blood cells, the thymus, lymph nodes and lymph channels, which are also part of the lymphatic system. The immune system provides a mechanism for the body to distinguish its own cells and tissues from alien cells and substances and to neutralize or destroy the latter by using specialized proteins such as antibodies, cytokines, and toll-like receptors, among many others. immunology immunology The main function of the lymphatic system is to extract, transport and metabolize lymph, the fluid found in between cells. The lymphatic system is very similar to the circulatory system in terms of both its structure and its most basic function (to carry a body fluid). oncology, immunology oncology, immunology The endocrine system consists of the principal endocrine glands: the pituitary, thyroid, adrenals, pancreas, parathyroids, andgonads, but nearly all organs and tissues produce specific endocrine hormones as well. The endocrine hormones serve as signals from one body system to another regarding an enormous array of conditions, and resulting in variety of changes of function. There is also the exocrine system. endocrinology Endocrinology Homeostasis[edit] The term “homeostasis” is the property of a system that regulates its internal environment and tends to maintain a stable, relatively constant condition of properties such as temperature or pH. It can be either an open or closed system. In simple terms, it is a process in which the body’s internal environment is kept stable. This is required for the body to function sufficiently. The Homeostatic process is essential for the survival of each cell, tissue, and body system. Maintaining a stable internal environment requires constant monitoring, mostly by the brain and nervous system. The brain receives information from the body and responds appropriately through the release of various substances like neurotransmitters, catecholamines, and hormones. Individual organ physiology furthermore facilitates the maintenance of homeostasis of the whole body e.g. Blood pressure regulation: the release of renin by the kidneys allow blood pressure to be stabilized (Renin, Angiotensinogen, Aldosterone System), though the brain helps regulate blood pressure by the Pituitary releasing Anti-Diuretic Hormone (ADH). Thus, homeostasis is maintained within the body as a whole, dependent upon its parts. The traditional divisions by system are somewhat arbitrary. Many body parts participate in more than one system, and systems might be organized by function, by embryological origin, or other categorizations. In particular, is the “neuroendocrine system”, the complex interactions of the neurological and endocrinological systems which together regulate physiology. Furthermore, many aspects of physiology are not as easily included in the traditional organ system categories. The study of how physiology is altered in disease is pathophysiology. Society and culture[edit] This section requires expansion.(November 2013) Further information: History of anatomy, History of medicine, and History of physiology Depiction[edit] This section requires expansion.(November 2013) Image of two facing pages of text, also including woodcuts of naked “Adam” and “Eve” figures. “Epitome”, fol. 10b and 11a. HMD Collection, WZ 240 V575dhZ 1543. Gross anatomy has become a key part of visual arts. Basic concepts of how muscles and bones function and deform with movement is key to drawing, painting or animating a human figure. Many books such as “Human Anatomy for Artists: The Elements of Form”, are written as a guide to drawing the human body anatomically correctly.[11] Leonardo da Vinci sought to improve his art through a better understanding of human anatomy. In the process he advanced both human anatomy and its representation in art. Because the structure of living organism is complex, anatomy is organized by levels, from the smallest components of cells to the largest organs and their relationship to other organs. Appearance[edit] Main article: Human physical appearance This section requires expansion.(November 2013) History of anatomy[edit] The history of anatomy has been characterized, over a long period of time, by a continually developing understanding of the functions of organs and structures in the body. Methods have also advanced dramatically, advancing from examination of animals through dissection of fresh and preserved cadavers (dead human bodies) to technologically complex techniques developed in the 20th century. History of physiology[edit] Main article: History of physiology The study of human physiology dates back to at least 420 B.C. and the time of Hippocrates, the father of medicine.[12] The critical thinking of Aristotle and his emphasis on the relationship between structure and function marked the beginning of physiology in Ancient Greece, while Claudius Galenus (c. 126-199 A.D.), known as Galen, was the first to use experiments to probe the function of the body. Galen was the founder of experimental physiology.[13] The medical world moved on from Galenism only with the appearance of Andreas Vesalius and William Harvey.[14] During the Middle Ages, the ancient Greek and Indian medical traditions were further developed by Muslim physicians. Notable work in this period was done by Avicenna (980-1037), author of the The Canon of Medicine, and Ibn al-Nafis (1213–1288), among others.[citation needed] Following from the Middle Ages, the Renaissance brought an increase of physiological research in the Western world that triggered the modern study of anatomy and physiology. Andreas Vesalius was an author of one of the most influential books on human anatomy, De humani corporis fabrica.[15] Vesalius is often referred to as the founder of modern human anatomy.[16] Anatomist William Harvey described thecirculatory system in the 17th century,[17] demonstrating the fruitful combination of close observations and careful experiments to learn about the functions of the body, which was fundamental to the development of experimental physiology. Herman Boerhaave is sometimes referred to as a father of physiology due to his exemplary teaching in Leiden and textbook Institutiones medicae (1708).[citation needed] In the 18th century, important works in this field were by Pierre Cabanis, a French doctor and physiologist.[citation needed] In the 19th century, physiological knowledge began to accumulate at a rapid rate, in particular with the 1838 appearance of the Cell theory of Matthias Schleiden and Theodor Schwann. It radically stated that organisms are made up of units called cells. Claude Bernard’s (1813–1878) further discoveries ultimately led to his concept of milieu interieur (internal environment), which would later be taken up and championed as “homeostasis” by American physiologist Walter Cannon (1871–1945).[clarification needed] In the 20th century, biologists also became interested in how organisms other than human beings function, eventually spawning the fields of comparative physiology and ecophysiology.[18] Major figures in these fields include Knut Schmidt-Nielsen and George Bartholomew. Most recently, evolutionary physiology has become a distinct subdiscipline.[19] The biological basis of the study of physiology, integration refers to the overlap of many functions of the systems of the human body, as well as its accompanied form. It is achieved through communication that occurs in a variety of ways, both electrical and chemical. In terms of the human body, the endocrine and nervous systems play major roles in the reception and transmission of signals that integrate function. Homeostasis is a major aspect with regard to the interactions within an organism, humans included. See also[edit] Wikimedia Commons has media related to Human body. • Outline of human anatomy • Body image • Body schema • Human development • Comparative physiology • Comparative anatomy Further reading[edit] • Raincoast Books (2004). Encyclopedic Atlas Human Body. Raincoast Books. ISBN 978-1-55192-747-3. • Daniel D. Chiras (1 June 2012). Human Body Systems: Structure, Function, and Environment. Jones & Bartlett Publishers. ISBN 978-1-4496-4793-3. • Adolf Faller; Michael Schünke; Gabriele Schünke; Ethan Taub, M.D. (2004). The Human Body: An Introduction to Structure and Function. Thieme. ISBN 978-1-58890-122-4. • Richard Walker (30 March 2009). Human Body. Dk Pub. ISBN 978-0-7566-4545-8. • DK Publishing (18 June 2012). Human Body: A Visual Encyclopedia. ISBN 978-1-4654-0143-4. • DK Publishing (30 August 2010). The Complete Human Body: The Definitive Visual Guide. ISBN 978-0-7566-7509-7. • Saddleback (1 January 2008). Human Body. Saddleback Educational Publ. ISBN 978-1-59905-234-2. • Babsky, Evgeni; Boris Khodorov, Grigory Kositsky, Anatoly Zubkov (1989). Evgeni Babsky, ed. Human Physiology, in 2 vols. Translated by Ludmila Aksenova; translation edited by H. C. Creighton (M.A.,Oxon). Moscow: Mir Publishers. ISBN 5-03-000776-8. • Sherwood, Lauralee (2010). Human Physiology from cells to systems (Hardcover) (7 ed.). Pacific Grove, CA: Brooks/cole. ISBN 978-0-495-39184-5. References[edit] 1. Jump up^ Page 21 Inside the human body: using scientific and exponential notation. Author: Greg Roza. Edition: Illustrated. Publisher: The Rosen Publishing Group, 2007. ISBN 1-4042-3362-8, ISBN 978-1-4042-3362-1. Length: 32pages 2. Jump up^ Cell Movements and the Shaping of the Vertebrate Body in Chapter 21 of Molecular Biology of the Cell fourth edition, edited by Bruce Alberts (2002) published by Garland Science. The Alberts text discusses how the “cellular building blocks” move to shape developing embryos. It is also common to describe small molecules such as amino acids as “molecular building blocks”. 3. ^ Jump up to:a b Page 3 in Chemical storylines. Author: George Burton. Edition 2, illustrated. Publisher: Heinemann, 2000. ISBN 0-435-63119-5, ISBN 978-0-435-63119-2. Length: 312 pages 4. Jump up^ http://www.human-body.org/ (dead link) 5. ^ Jump up to:a b c d e f “Introduction page, “Anatomy of the Human Body”. Henry Gray. 20th edition. 1918″. Retrieved 27 March 2007. 6. Jump up^ “Publisher’s page for Gray’s Anatomy. 39th edition (UK). 2004. ISBN 0-443-07168-3”. Archived from the original on 20 February 2007. Retrieved 27 March 2007. 7. Jump up^ “Publisher’s page for Gray’s Anatomy. 39th edition (US). 2004. ISBN 0-443-07168-3”. Archived from the original on 9 February 2007. Retrieved 27 March 2007. 8. Jump up^ “Cardiovascular System”. U.S. National Cancer Institute. Retrieved 2008-09-16.[dead link] 9. Jump up^ Human Biology and Health. Upper Saddle River, NJ: Pearson Prentice Hall. 1993. ISBN 0-13-981176-1. 10. Jump up^ “The Cardiovascular System”. SUNY Downstate Medical Center. 2008-03-08. Retrieved 2008-09-16. 11. Jump up^ Goldfinger, Eliot (1991). Human Anatomy for Artists: The Elements of Form. Oxford University Press. ISBN 0-19-505206-4. 12. Jump up^ “Physiology – History of physiology, Branches of physiology”. http://www.Scienceclarified.com. Retrieved 2010-08-29. 13. Jump up^ Fell, C.; Griffith Pearson, F. (November 2007). “Thoracic Surgery Clinics: Historical Perspectives of Thoracic Anatomy”. Thorac Surg Clin 17 (4): 443–8, v. doi:10.1016/j.thorsurg.2006.12.001. 14. Jump up^ “Galen”. Discoveriesinmedicine.com. Retrieved 2010-08-29. 15. Jump up^ “Page through a virtual copy of Vesalius’s De Humanis Corporis Fabrica”. Archive.nlm.nih.gov. Retrieved 2010-08-29. 16. Jump up^ “Andreas Vesalius (1514-1567)”. Ingentaconnect.com. 1999-05-01. Retrieved 2010-08-29. 17. Jump up^ Zimmer, Carl (2004). “Soul Made Flesh: The Discovery of the Brain – and How It Changed the World”. J Clin Invest 114 (5): 604–604. doi:10.1172/JCI22882. 18. Jump up^ Feder, Martin E. (1987). New directions in ecological physiology. New York: Cambridge Univ. Press. ISBN 978-0-521-34938-3. 19. Jump up^ Garland, Jr, Theodore; Carter, P. A. (1994). “Evolutionary physiology”. Annual Review of Physiology 56 (56): 579–621. doi:10.1146/annurev.ph.56.030194.003051. PMID 8010752. External links[edit] Look up body in Wiktionary, the free dictionary. Wikibooks has a book on the topic of: Human Physiology • Human Physiology textbook at Wikibooks • (English) (Arabic) The Book of Humans from the early 18th century • Referencing site and detailed pictures showing information on the human body anatomy and structure [show] • V • T • E Human systems and organs [show] • V • T • E Physiology types [show] • V • T • E Medicine Help improve this page What’s this? Did you find what you were looking for? 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If we all gave $3, the fundraiser would be over in an hour. x Brain From Wikipedia, the free encyclopedia (Redirected from The Brain) This article is about the brains of all types of animals, including humans. For information specific to the human brain, see Human brain. For other uses, see Brain (disambiguation). A chimpanzee brain The brain is an organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals—only a few invertebrates such as sponges, jellyfish, adult sea squirts and starfish do not have a brain, even if diffuse neural tissue is present. It is located in the head, usually close to the primary sensory organs for such senses as vision, hearing, balance, taste, and smell. The brain is the most complex organ in a vertebrate’s body. In a typical human the cerebral cortex (the largest part) is estimated to contain 15–33 billion neurons,[1] each connected bysynapses to several thousand other neurons. These neurons communicate with one another by means of long protoplasmic fibers called axons, which carry trains of signal pulses called action potentials to distant parts of the brain or body targeting specific recipient cells. Physiologically, the function of the brain is to exert centralized control over the other organs of the body. The brain acts on the rest of the body both by generating patterns of muscle activity and by driving the secretion of chemicals called hormones. This centralized control allows rapid and coordinated responses to changes in the environment. Some basic types of responsiveness such as reflexes can be mediated by the spinal cord or peripheral ganglia, but sophisticated purposeful control of behavior based on complex sensory input requires the information-integrating capabilities of a centralized brain. From a philosophical point of view, what makes the brain special in comparison to other organs is that it forms the physical structure associated with the mind. As Hippocrates put it: “Men ought to know that from nothing else but the brain come joys, delights, laughter and sports, and sorrows, griefs, despondency, and lamentations.”[2] Through much of history, the mind was thought to be separate from the brain. Even for present-day neuroscience, the mechanisms by which brain activity gives rise to consciousness and thought remain very challenging to understand: despite rapid scientific progress, much about how the brain works remains a mystery. The operations of individual brain cells are now understood in considerable detail, but the way they cooperate in ensembles of millions has yet to be solved. The most promising approaches treat the brain as a biological computer, very different in mechanism from an electronic computer, but similar in the sense that it acquires information from the surrounding world, stores it, and processes it in a variety of ways, analogous to the central processing unit (CPU) in a computer. This article compares the properties of brains across the entire range of animal species, with the greatest attention to vertebrates. It deals with the human brain insofar as it shares the properties of other brains. The ways in which the human brain differs from other brains are covered in the human brain article. Several topics that might be covered here are instead covered there because much more can be said about them in a human context. The most important is brain disease and the effects of brain damage, covered in the human brain article because the most common diseases of the human brain either do not show up in other species, or else manifest themselves in different ways. Contents [hide] • 1 Anatomy o 1.1 Cellular structure o 1.2 Evolution • 1.2.1 The generic bilaterian nervous system • 1.2.2 Invertebrates • 1.2.3 Vertebrates • 1.2.4 Mammals • 1.2.5 Primates • 2 Physiology o 2.1 Neurotransmitters and receptors o 2.2 Electrical activity o 2.3 Metabolism • 3 Functions o 3.1 Information processing o 3.2 Perception o 3.3 Motor control o 3.4 Arousal o 3.5 Homeostasis o 3.6 Motivation o 3.7 Learning and memory • 4 Development • 5 Research • 6 History • 7 See also • 8 References • 9 External links Anatomy[edit] Cross section of the olfactory bulb of a rat, stained in two different ways at the same time: one stain shows neuron cell bodies, the other shows receptors for theneurotransmitter GABA. The shape and size of the brains of different species vary greatly, and identifying common features is often difficult.[3] Nevertheless, there are a number of principles of brain architecture that apply across a wide range of species.[4] Some aspects of brain structure are common to almost the entire range of animal species;[5] others distinguish “advanced” brains from more primitive ones, or distinguish vertebrates from invertebrates.[3] The simplest way to gain information about brain anatomy is by visual inspection, but many more sophisticated techniques have been developed. Brain tissue in its natural state is too soft to work with, but it can be hardened by immersion in alcohol or other fixatives, and then sliced apart for examination of the interior. Visually, the interior of the brain consists of areas of so-called grey matter, with a dark color, separated by areas ofwhite matter, with a lighter color. Further information can be gained by staining slices of brain tissue with a variety of chemicals that bring out areas where specific types of molecules are present in high concentrations. It is also possible to examine the microstructure of brain tissue using a microscope, and to trace the pattern of connections from one brain area to another.[6] Cellular structure[edit] Neurons generate electrical signals that travel along their axons. When a pulse of electricity reaches a junction called a synapse, it causes a neurotransmitter chemical to be released, which binds to receptors on other cells and thereby alters their electrical activity. The brains of all species are composed primarily of two broad classes of cells: neurons and glial cells. Glial cells (also known as glia or neuroglia) come in several types, and perform a number of critical functions, including structural support, metabolic support, insulation, and guidance of development. Neurons, however, are usually considered the most important cells in the brain.[7] The property that makes neurons unique is their ability to send signals to specific target cells over long distances.[7] They send these signals by means of an axon, which is a thin protoplasmic fiber that extends from the cell body and projects, usually with numerous branches, to other areas, sometimes nearby, sometimes in distant parts of the brain or body. The length of an axon can be extraordinary: for example, if a pyramidal cell, (an excitatory neuron) of the cerebral cortex were magnified so that its cell body became the size of a human body, its axon, equally magnified, would become a cable a few centimeters in diameter, extending more than a kilometer.[8] These axons transmit signals in the form of electrochemical pulses called action potentials, which last less than a thousandth of a second and travel along the axon at speeds of 1–100 meters per second. Some neurons emit action potentials constantly, at rates of 10–100 per second, usually in irregular patterns; other neurons are quiet most of the time, but occasionally emit a burst of action potentials.[9] Axons transmit signals to other neurons by means of specialized junctions called synapses. A single axon may make as many as several thousand synaptic connections with other cells.[7] When an action potential, traveling along an axon, arrives at a synapse, it causes a chemical called a neurotransmitter to be released. The neurotransmitter binds to receptor molecules in the membrane of the target cell.[7] Neurons often have extensive networks of dendrites, which receive synaptic connections. Shown is a pyramidal neuronfrom the hippocampus, stained for green fluorescent protein. Synapses are the key functional elements of the brain.[10] The essential function of the brain is cell-to-cell communication, and synapses are the points at which communication occurs. The human brain has been estimated to contain approximately 100 trillion synapses;[11] even the brain of a fruit fly contains several million.[12] The functions of these synapses are very diverse: some are excitatory (exciting the target cell); others are inhibitory; others work by activatingsecond messenger systems that change the internal chemistry of their target cells in complex ways.[10] A large number of synapses are dynamically modifiable; that is, they are capable of changing strength in a way that is controlled by the patterns of signals that pass through them. It is widely believed that activity-dependent modification of synapses is the brain’s primary mechanism for learning and memory.[10] Most of the space in the brain is taken up by axons, which are often bundled together in what are called nerve fiber tracts. A myelinated axon is wrapped in a fatty insulating sheath of myelin, which serves to greatly increase the speed of signal propagation. (There are also unmyelinated axons). Myelin is white, making parts of the brain filled exclusively with nerve fibers appear as light-colored white matter, in contrast to the darker-colored grey matter that marks areas with high densities of neuron cell bodies.[7] Evolution[edit] Main article: Evolution of the brain The generic bilaterian nervous system[edit] Nervous system of a generic bilaterian animal, in the form of a nerve cord with segmental enlargements, and a “brain” at the front Except for a few primitive organisms such as sponges (which have no nervous system[13]) and cnidarians (which have a nervous system consisting of a diffuse nerve net[13]), all living multicellular animals are bilaterians, meaning animals with a bilaterally symmetric body shape (that is, left and right sides that are approximate mirror images of each other).[14] All bilaterians are thought to have descended from a common ancestor that appeared early in the Cambrian period, 550–600 million years ago, and it has been hypothesized that this common ancestor had the shape of a simple tubeworm with a segmented body.[14] At a schematic level, that basic worm-shape continues to be reflected in the body and nervous system architecture of all modern bilaterians, including vertebrates.[15] The fundamental bilateral body form is a tube with a hollow gut cavity running from the mouth to the anus, and a nerve cord with an enlargement (a ganglion) for each body segment, with an especially large ganglion at the front, called the brain. The brain is small and simple in some species, such as nematode worms; in other species, including vertebrates, it is the most complex organ in the body.[3] Some types of worms, such as leeches, also have an enlarged ganglion at the back end of the nerve cord, known as a “tail brain”.[16] There are a few types of existing bilaterians that lack a recognizable brain, including echinoderms, tunicates, and acoelomorphs (a group of primitive flatworms). It has not been definitively established whether the existence of these brainless species indicates that the earliest bilaterians lacked a brain, or whether their ancestors evolved in a way that led to the disappearance of a previously existing brain structure.[17] Invertebrates[edit] Fruit flies (Drosophila) have been extensively studied to gain insight into the role of genes in brain development. This category includes arthropods, molluscs, and numerous types of worms. The diversity of invertebrate body plans is matched by an equal diversity in brain structures.[18] Two groups of invertebrates have notably complex brains: arthropods (insects, crustaceans, arachnids, and others), and cephalopods(octopuses, squids, and similar molluscs).[19] The brains of arthropods and cephalopods arise from twin parallel nerve cords that extend through the body of the animal. Arthropods have a central brain with three divisions and large optical lobes behind each eye for visual processing.[19]Cephalopods such as the octopus and squid have the largest brains of any invertebrates.[20] There are several invertebrate species whose brains have been studied intensively because they have properties that make them convenient for experimental work: • Fruit flies (Drosophila), because of the large array of techniques available for studying their genetics, have been a natural subject for studying the role of genes in brain development.[21] In spite of the large evolutionary distance between insects and mammals, many aspects ofDrosophila neurogenetics have been shown to be relevant to humans. The first biological clock genes, for example, were identified by examining Drosophila mutants that showed disrupted daily activity cycles.[22] A search in the genomes of vertebrates revealed a set of analogous genes, which were found to play similar roles in the mouse biological clock—and therefore almost certainly in the human biological clock as well.[23] • The nematode worm Caenorhabditis elegans, like Drosophila, has been studied largely because of its importance in genetics.[24] In the early 1970s, Sydney Brenner chose it as a model system for studying the way that genes control development. One of the advantages of working with this worm is that the body plan is very stereotyped: the nervous system of thehermaphrodite morph contains exactly 302 neurons, always in the same places, making identical synaptic connections in every worm.[25] Brenner’s team sliced worms into thousands of ultrathin sections and photographed each one under an electron microscope, then visually matched fibers from section to section, to map out every neuron and synapse in the entire body.[26] Nothing approaching this level of detail is available for any other organism, and the information gained has enabled a multitude of studies that would otherwise have not been possible.[27] • The sea slug Aplysia californica, was chosen by Nobel Prize-winning neurophysiologist Eric Kandel as a model for studying the cellular basis of learning and memory, because of the simplicity and accessibility of its nervous system, and it has been examined in hundreds of experiments.[28] Vertebrates[edit] The brain of a shark The first vertebrates appeared over 500 million years ago (Mya), during the Cambrian period, and may have resembled the modern hagfish in form.[29]Sharks appeared about 450 Mya, amphibians about 400 Mya, reptiles about 350 Mya, and mammals about 200 Mya. No modern species should be described as more “primitive” than others, strictly speaking, since each has an equally long evolutionary history—but the brains of modern hagfishes,lampreys, sharks, amphibians, reptiles, and mammals show a gradient of size and complexity that roughly follows the evolutionary sequence. All of these brains contain the same set of basic anatomical components, but many are rudimentary in the hagfish, whereas in mammals the foremost part (thetelencephalon) is greatly elaborated and expanded.[30] Brains are most simply compared in terms of their size. The relationship between brain size, body size and other variables has been studied across a wide range of vertebrate species. As a rule, brain size increases with body size, but not in a simple linear proportion. In general, smaller animals tend to have larger brains, measured as a fraction of body size: the animal with the largest brain-size-to-body-size ratio is the hummingbird.[citation needed] For mammals, the relationship between brain volume and body mass essentially follows a power law with an exponent of about 0.75.[31] This formula describes the central tendency, but every family of mammals departs from it to some degree, in a way that reflects in part the complexity of their behavior. For example, primates have brains 5 to 10 times larger than the formula predicts. Predators tend to have larger brains than their prey, relative to body size.[32] The main subdivisions of the embryonicvertebrate brain, which later differentiate into the forebrain, midbrain and hindbrain All vertebrate brains share a common underlying form, which appears most clearly during early stages of embryonic development. In its earliest form, the brain appears as three swellings at the front end of the neural tube; these swellings eventually become the forebrain, midbrain, and hindbrain (the prosencephalon, mesencephalon, and rhombencephalon, respectively). At the earliest stages of brain development, the three areas are roughly equal in size. In many classes of vertebrates, such as fish and amphibians, the three parts remain similar in size in the adult, but in mammals the forebrain becomes much larger than the other parts, and the midbrain becomes very small.[7] The brains of vertebrates are made of very soft tissue.[7] Living brain tissue is pinkish on the outside and mostly white on the inside, with subtle variations in color. Vertebrate brains are surrounded by a system of connective tissue membranes called meninges that separate the skull from the brain. Blood vessels enter the central nervous system through holes in the meningeal layers. The cells in the blood vessel walls are joined tightly to one another, forming the blood–brain barrier, which blocks the passage of many toxins and pathogens[33] (though at the same time blocking antibodies and some drugs, thereby presenting special challenges in treatment of diseases of the brain).[citation needed] Neuroanatomists usually divide the vertebrate brain into six main regions: the telencephalon (cerebral hemispheres), diencephalon(thalamus and hypothalamus), mesencephalon (midbrain), cerebellum, pons, and medulla oblongata. Each of these areas has a complex internal structure. Some parts, such as the cerebral cortex and the cerebellar cortex, consist of layers that are folded or convoluted to fit within the available space. Other parts, such as the thalamus and hypothalamus, consist of clusters of many small nuclei. Thousands of distinguishable areas can be identified within the vertebrate brain based on fine distinctions of neural structure, chemistry, and connectivity.[7] Although the same basic components are present in all vertebrate brains, some branches of vertebrate evolution have led to substantial distortions of brain geometry, especially in the forebrain area. The brain of a shark shows the basic components in a straightforward way, but in teleost fishes (the great majority of existing fish species), the forebrain has become “everted”, like a sock turned inside out. In birds, there are also major changes in forebrain structure.[34] These distortions can make it difficult to match brain components from one species with those of another species.[35] The main anatomical regions of the vertebrate brain, shown for shark and human. The same parts are present, but they differ greatly in size and shape. Here is a list of some of the most important vertebrate brain components, along with a brief description of their functions as currently understood: • The medulla, along with the spinal cord, contains many small nuclei involved in a wide variety of sensory and motor functions.[7] • The pons lies in the brainstem directly above the medulla. Among other things, it contains nuclei that control sleep, respiration, swallowing, bladder function, equilibrium, eye movement, facial expressions, and posture.[36] • The hypothalamus is a small region at the base of the forebrain, whose complexity and importance belies its size. It is composed of numerous small nuclei, each with distinct connections and neurochemistry. The hypothalamus regulates sleep and wake cycles, eating and drinking, hormone release, and many other critical biological functions.[37] • The thalamus is another collection of nuclei with diverse functions. Some are involved in relaying information to and from the cerebral hemispheres. Others are involved in motivation. The subthalamic area (zona incerta) seems to contain action-generating systems for several types of “consummatory” behaviors, including eating, drinking, defecation, and copulation.[38] • The cerebellum modulates the outputs of other brain systems to make them precise. Removal of the cerebellum does not prevent an animal from doing anything in particular, but it makes actions hesitant and clumsy. This precision is not built-in, but learned by trial and error. Learning how to ride a bicycle is an example of a type of neural plasticity that may take place largely within the cerebellum.[7] • The optic tectum allows actions to be directed toward points in space, most commonly in response to visual input. In mammals it is usually referred to as the superior colliculus, and its best-studied function is to direct eye movements. It also directs reaching movements and other object-directed actions. It receives strong visual inputs, but also inputs from other senses that are useful in directing actions, such as auditory input in owls and input from the thermosensitive pit organs in snakes. In some fishes, such as lampreys, this region is the largest part of the brain.[39] The superior colliculus is part of the midbrain. • The pallium is a layer of gray matter that lies on the surface of the forebrain. In reptiles and mammals, it is called the cerebral cortex. Multiple functions involve the pallium, including olfaction and spatial memory. In mammals, where it becomes so large as to dominate the brain, it takes over functions from many other brain areas. In many mammals, the cerebral cortex consists of folded bulges called gyri that create deep furrows or fissures called sulci. The folds increase the surface area of the cortex and therefore increase the amount of gray matter and the amount of information that can be processed.[40] • The hippocampus, strictly speaking, is found only in mammals. However, the area it derives from, the medial pallium, has counterparts in all vertebrates. There is evidence that this part of the brain is involved in spatial memory and navigation in fishes, birds, reptiles, and mammals.[41] • The basal ganglia are a group of interconnected structures in the forebrain. The primary function of the basal ganglia appears to be action selection: they send inhibitory signals to all parts of the brain that can generate motor behaviors, and in the right circumstances can release the inhibition, so that the action-generating systems are able to execute their actions. Reward and punishment exert their most important neural effects by altering connections within the basal ganglia.[42] • The olfactory bulb is a special structure that processes olfactory sensory signals and sends its output to the olfactory part of the pallium. It is a major brain component in many vertebrates, but is greatly reduced in primates.[43] Mammals[edit] The most obvious difference between the brains of mammals and other vertebrates is in terms of size. On average, a mammal has a brain roughly twice as large as that of a bird of the same body size, and ten times as large as that of a reptile of the same body size.[44] Size, however, is not the only difference: there are also substantial differences in shape. The hindbrain and midbrain of mammals are generally similar to those of other vertebrates, but dramatic differences appear in the forebrain, which is greatly enlarged and also altered in structure.[45] The cerebral cortex is the part of the brain that most strongly distinguishes mammals. In non-mammalian vertebrates, the surface of the cerebrum is lined with a comparatively simple three-layered structure called the pallium. In mammals, the pallium evolves into a complex six-layered structure called neocortex or isocortex.[46] Several areas at the edge of the neocortex, including the hippocampus and amygdala, are also much more extensively developed in mammals than in other vertebrates.[45] The elaboration of the cerebral cortex carries with it changes to other brain areas. The superior colliculus, which plays a major role in visual control of behavior in most vertebrates, shrinks to a small size in mammals, and many of its functions are taken over by visual areas of the cerebral cortex.[44] The cerebellum of mammals contains a large portion (the neocerebellum) dedicated to supporting the cerebral cortex, which has no counterpart in other vertebrates.[47] Primates[edit] Encephalization Quotient Species EQ[48] Human 7.4–7.8 Chimpanzee 2.2–2.5 Rhesus monkey 2.1 Bottlenose dolphin 4.14[49] Elephant 1.13–2.36[50] Dog 1.2 Horse 0.9 Rat 0.4 See also: Human brain The brains of humans and other primates contain the same structures as the brains of other mammals, but are generally larger in proportion to body size.[51] The most widely accepted way of comparing brain sizes across species is the so-called encephalization quotient (EQ), which takes into account the nonlinearity of the brain-to-body relationship.[48] Humans have an average EQ in the 7-to-8 range, while most other primates have an EQ in the 2-to-3 range. Dolphins have values higher than those of primates other than humans,[49] but nearly all other mammals have EQ values that are substantially lower. Most of the enlargement of the primate brain comes from a massive expansion of the cerebral cortex, especially the prefrontal cortex and the parts of the cortex involved in vision.[52] The visual processing network of primates includes at least 30 distinguishable brain areas, with a complex web of interconnections. It has been estimated that visual processing areas occupy more than half of the total surface of the primate neocortex.[53] Theprefrontal cortex carries out functions that include planning, working memory, motivation, attention, and executive control. It takes up a much larger proportion of the brain for primates than for other species, and an especially large fraction of the human brain.[54] Physiology[edit] The functions of the brain depend on the ability of neurons to transmit electrochemical signals to other cells, and their ability to respond appropriately to electrochemical signals received from other cells. The electrical properties of neurons are controlled by a wide variety of biochemical and metabolic processes, most notably the interactions between neurotransmitters and receptors that take place at synapses.[7] Neurotransmitters and receptors[edit] Neurotransmitters are chemicals that are released at synapses when an action potential activates them—neurotransmitters attach themselves to receptor molecules on the membrane of the synapse’s target cell, and thereby alter the electrical or chemical properties of the receptor molecules. With few exceptions, each neuron in the brain releases the same chemical neurotransmitter, or combination of neurotransmitters, at all the synaptic connections it makes with other neurons; this rule is known as Dale’s principle.[7] Thus, a neuron can be characterized by the neurotransmitters that it releases. The great majority of psychoactive drugs exert their effects by altering specific neurotransmitter systems. This applies to drugs such as marijuana, nicotine, heroin, cocaine, alcohol, fluoxetine, chlorpromazine, and many others.[55] The two neurotransmitters that are used most widely in the vertebrate brain are glutamate, which almost always exerts excitatory effects on target neurons, and gamma-aminobutyric acid(GABA), which is almost always inhibitory. Neurons using these transmitters can be found in nearly every part of the brain.[56] Because of their ubiquity, drugs that act on glutamate or GABA tend to have broad and powerful effects. Some general anesthetics act by reducing the effects of glutamate; most tranquilizers exert their sedative effects by enhancing the effects of GABA.[57] There are dozens of other chemical neurotransmitters that are used in more limited areas of the brain, often areas dedicated to a particular function. Serotonin, for example—the primary target of antidepressant drugs and many dietary aids—comes exclusively from a small brainstem area called the Raphe nuclei.[58] Norepinephrine, which is involved in arousal, comes exclusively from a nearby small area called the locus coeruleus.[59] Other neurotransmitters such as acetylcholine and dopamine have multiple sources in the brain, but are not as ubiquitously distributed as glutamate and GABA.[60] Electrical activity[edit] Brain electrical activity recorded from a human patient during an epileptic seizure As a side effect of the electrochemical processes used by neurons for signaling, brain tissue generates electric fields when it is active. When large numbers of neurons show synchronized activity, the electric fields that they generate can be large enough to detect outside the skull, usingelectroencephalography (EEG) [61] or magnetoencephalography (MEG). EEG recordings, along with recordings made from electrodes implanted inside the brains of animals such as rats, show that the brain of a living animal is constantly active, even during sleep.[62] Each part of the brain shows a mixture of rhythmic and nonrhythmic activity, which may vary according to behavioral state. In mammals, the cerebral cortex tends to show large slow delta waves during sleep, faster alpha waves when the animal is awake but inattentive, and chaotic-looking irregular activity when the animal is actively engaged in a task. During an epileptic seizure, the brain’s inhibitory control mechanisms fail to function and electrical activity rises to pathological levels, producing EEG traces that show large wave and spike patterns not seen in a healthy brain. Relating these population-level patterns to the computational functions of individual neurons is a major focus of current research in neurophysiology.[62] Metabolism[edit] All vertebrates have a blood–brain barrier that allows metabolism inside the brain to operate differently from metabolism in other parts of the body. Glial cells play a major role in brain metabolism by controlling the chemical composition of the fluid that surrounds neurons, including levels of ions and nutrients.[63] Brain tissue consumes a large amount of energy in proportion to its volume, so large brains place severe metabolic demands on animals. The need to limit body weight in order, for example, to fly, has apparently led to selection for a reduction of brain size in some species, such as bats.[64] Most of the brain’s energy consumption goes into sustaining the electric charge (membrane potential) of neurons.[63] Most vertebrate species devote between 2% and 8% of basal metabolism to the brain. In primates, however, the percentage is much higher—in humans it rises to 20–25%.[65] The energy consumption of the brain does not vary greatly over time, but active regions of the cerebral cortex consume somewhat more energy than inactive regions; this forms the basis for the functional brain imaging methods PET, fMRI,[66] and NIRS.[67] The brain typically gets most of its energy from oxygen-dependent metabolism of glucose (i.e., blood sugar),[63] but ketones provide a major alternative source, together with contributions from medium chain fatty acids (octanoic[68] and heptanoic[69] acids), lactate,[70] acetate,[71] and possibly amino acids.[72] Functions[edit] Further information: Dualism (philosophy of mind) From an evolutionary-biological perspective, the function of the brain is to provide coherent control over the actions of an animal. A centralized brain allows groups of muscles to be co-activated in complex patterns; it also allows stimuli impinging on one part of the body to evoke responses in other parts, and it can prevent different parts of the body from acting at cross-purposes to each other.[73] To generate purposeful and unified action, the brain first brings information from sense organs together at a central location. It then processes this raw data to extract information about the structure of the environment. Next it combines the processed sensory information with information about the current needs of an animal and with memory of past circumstances. Finally, on the basis of the results, it generates motor response patterns that are suited to maximize the welfare of the animal. These signal-processing tasks require intricate interplay between a variety of functional subsystems.[73] Information processing[edit] The invention of electronic computers in the 1940s, along with the development of mathematical information theory, led to a realization that brains can potentially be understood as information processing systems. This concept formed the basis of the field of cybernetics, and eventually gave rise to the field now known as computational neuroscience.[74] The earliest attempts at cybernetics were somewhat crude in that they treated the brain as essentially a digital computer in disguise, as for example in John von Neumann’s 1958 book, The Computer and the Brain.[75] Over the years, though, accumulating information about the electrical responses of brain cells recorded from behaving animals has steadily moved theoretical concepts in the direction of increasing realism.[74] Model of a neural circuit in thecerebellum, as proposed by James S. Albus The essence of the information processing approach is to try to understand brain function in terms of information flow and implementation ofalgorithms.[74] One of the most influential early contributions was a 1959 paper titled What the frog’s eye tells the frog’s brain: the paper examined the visual responses of neurons in the retina and optic tectum of frogs, and came to the conclusion that some neurons in the tectum of the frog are wired to combine elementary responses in a way that makes them function as “bug perceivers”.[76] A few years later David Hubeland Torsten Wiesel discovered cells in the primary visual cortex of monkeys that become active when sharp edges move across specific points in the field of view—a discovery for which they won a Nobel Prize.[77] Follow-up studies in higher-order visual areas found cells that detect binocular disparity, color, movement, and aspects of shape, with areas located at increasing distances from the primary visual cortex showing increasingly complex responses.[78] Other investigations of brain areas unrelated to vision have revealed cells with a wide variety of response correlates, some related to memory, some to abstract types of cognition such as space.[79] Theorists have worked to understand these response patterns by constructing mathematical models of neurons and neural networks, which can be simulated using computers.[74] Some useful models are abstract, focusing on the conceptual structure of neural algorithms rather than the details of how they are implemented in the brain; other models attempt to incorporate data about the biophysical properties of real neurons.[80]No model on any level is yet considered to be a fully valid description of brain function, though. The essential difficulty is that sophisticated computation by neural networks requires distributed processing in which hundreds or thousands of neurons work cooperatively—current methods of brain activity recording are only capable of isolating action potentials from a few dozen neurons at a time.[81] Perception[edit] Diagram of signal processing in theauditory system One of the primary functions of a brain is to extract biologically relevant information from sensory inputs. The human brain is provided with information about light, sound, the chemical composition of the atmosphere, temperature, head orientation, limb position, the chemical composition of the bloodstream, and more. In other animals additional senses may be present, such as the infrared heat-sense of snakes, the magnetic field sense of some birds, or the electric field sense of some types of fish. Moreover, other animals may develop existing sensory systems in new ways, such as the adaptation by bats of the auditory sense into a form of sonar. One way or another, all of these sensory modalities are initially detected by specialized sensors that project signals into the brain.[7] Each sensory system begins with specialized receptor cells, such as light-receptive neurons in the retina of the eye, vibration-sensitive neurons in the cochlea of the ear, or pressure-sensitive neurons in the skin. The axons of sensory receptor cells travel into the spinal cord or brain, where they transmit their signals to a first-order sensory nucleus dedicated to one specific sensory modality. This primary sensory nucleus sends information to higher-order sensory areas that are dedicated to the same modality. Eventually, via a way-station in the thalamus, the signals are sent to the cerebral cortex, where they are processed to extract biologically relevant features, and integrated with signals coming from other sensory systems.[7] Motor control[edit] Motor systems are areas of the brain that are directly or indirectly involved in producing body movements, that is, in activating muscles. Except for the muscles that control the eye, which are driven by nuclei in the midbrain, all the voluntary muscles in the body are directly innervated by motor neurons in the spinal cord and hindbrain.[7] Spinal motor neurons are controlled both by neural circuits intrinsic to the spinal cord, and by inputs that descend from the brain. The intrinsic spinal circuits implement many reflex responses, and contain pattern generatorsfor rhythmic movements such as walking or swimming. The descending connections from the brain allow for more sophisticated control.[7] The brain contains several motor areas that project directly to the spinal cord. At the lowest level are motor areas in the medulla and pons, which control stereotyped movements such as walking, breathing, or swallowing. At a higher level are areas in the midbrain, such as the red nucleus, which is responsible for coordinating movements of the arms and legs. At a higher level yet is the primary motor cortex, a strip of tissue located at the posterior edge of the frontal lobe. The primary motor cortex sends projections to the subcortical motor areas, but also sends a massive projection directly to the spinal cord, through the pyramidal tract. This direct corticospinal projection allows for precise voluntary control of the fine details of movements. Other motor-related brain areas exert secondary effects by projecting to the primary motor areas. Among the most important secondary areas are the premotor cortex, basal ganglia, and cerebellum.[7] Major areas involved in controlling movement Area Location Function Ventral horn Spinal cord Contains motor neurons that directly activate muscles[82] Oculomotor nuclei Midbrain Contains motor neurons that directly activate the eye muscles[83] Cerebellum Hindbrain Calibrates precision and timing of movements[7] Basal ganglia Forebrain Action selection on the basis of motivation[84] Motor cortex Frontal lobe Direct cortical activation of spinal motor circuits Premotor cortex Frontal lobe Groups elementary movements into coordinated patterns[7] Supplementary motor area Frontal lobe Sequences movements into temporal patterns[85] Prefrontal cortex Frontal lobe Planning and other executive functions[86] In addition to all of the above, the brain and spinal cord contain extensive circuitry to control the autonomic nervous system, which works by secreting hormones and by modulating the “smooth” muscles of the gut.[7] The autonomic nervous system affects heart rate, digestion, respiration rate, salivation, perspiration, urination, and sexual arousal, and several other processes. Most of its functions are not under direct voluntary control. Arousal[edit] See also: Sleep Perhaps the most obvious aspect of the behavior of any animal is the daily cycle between sleeping and waking. Arousal and alertness are also modulated on a finer time scale, though, by an extensive network of brain areas.[7] A key component of the arousal system is the suprachiasmatic nucleus (SCN), a tiny part of the hypothalamus located directly above the point at which the optic nerves from the two eyes cross. The SCN contains the body’s central biological clock. Neurons there show activity levels that rise and fall with a period of about 24 hours, circadian rhythms: these activity fluctuations are driven by rhythmic changes in expression of a set of “clock genes”. The SCN continues to keep time even if it is excised from the brain and placed in a dish of warm nutrient solution, but it ordinarily receives input from the optic nerves, through the retinohypothalamic tract (RHT), that allows daily light-dark cycles to calibrate the clock.[87] The SCN projects to a set of areas in the hypothalamus, brainstem, and midbrain that are involved in implementing sleep-wake cycles. An important component of the system is the reticular formation, a group of neuron-clusters scattered diffusely through the core of the lower brain. Reticular neurons send signals to the thalamus, which in turn sends activity-level-controlling signals to every part of the cortex. Damage to the reticular formation can produce a permanent state of coma.[7] Sleep involves great changes in brain activity.[7] Until the 1950s it was generally believed that the brain essentially shuts off during sleep,[88] but this is now known to be far from true; activity continues, but patterns become very different. There are two types of sleep: REM sleep (with dreaming) and NREM (non-REM, usually without dreaming) sleep, which repeat in slightly varying patterns throughout a sleep episode. Three broad types of distinct brain activity patterns can be measured: REM, light NREM and deep NREM. During deep NREM sleep, also called slow wave sleep, activity in the cortex takes the form of large synchronized waves, whereas in the waking state it is noisy and desynchronized. Levels of the neurotransmittersnorepinephrine and serotonin drop during slow wave sleep, and fall almost to zero during REM sleep; levels of acetylcholine show the reverse pattern.[7] Homeostasis[edit] Cross-section of a human head, showing location of the hypothalamus For any animal, survival requires maintaining a variety of parameters of bodily state within a limited range of variation: these include temperature, water content, salt concentration in the bloodstream, blood glucose levels, blood oxygen level, and others.[89] The ability of an animal to regulate the internal environment of its body—the milieu intérieur, as pioneering physiologist Claude Bernard called it—is known as homeostasis (Greekfor “standing still”).[90] Maintaining homeostasis is a crucial function of the brain. The basic principle that underlies homeostasis is negative feedback: any time a parameter diverges from its set-point, sensors generate an error signal that evokes a response that causes the parameter to shift back toward its optimum value.[89] (This principle is widely used in engineering, for example in the control of temperature using athermostat.) In vertebrates, the part of the brain that plays the greatest role is the hypothalamus, a small region at the base of the forebrain whose size does not reflect its complexity or the importance of its function.[89] The hypothalamus is a collection of small nuclei, most of which are involved in basic biological functions. Some of these functions relate to arousal or to social interactions such as sexuality, aggression, or maternal behaviors; but many of them relate to homeostasis. Several hypothalamic nuclei receive input from sensors located in the lining of blood vessels, conveying information about temperature, sodium level, glucose level, blood oxygen level, and other parameters. These hypothalamic nuclei send output signals to motor areas that can generate actions to rectify deficiencies. Some of the outputs also go to the pituitary gland, a tiny gland attached to the brain directly underneath the hypothalamus. The pituitary gland secretes hormones into the bloodstream, where they circulate throughout the body and induce changes in cellular activity.[91] Motivation[edit] Components of the basal ganglia, shown in two cross-sections of the human brain. Blue: caudate nucleus and putamen. Green: globus pallidus. Red: subthalamic nucleus. Black: substantia nigra. According to evolutionary theory, individuals are genetically programmed to behave in ways that ensure survival and reproductive success. This overarching goal of genetic fitness translates into a set of specific survival-promoting behaviors, such as seeking food, water, shelter, and/or a mate.[92] The motivational system in the brain monitors the current state of satisfaction of these goals, and activates behaviors to meet any needs that arise. The motivational system works largely by a reward–punishment mechanism. When a particular behavior is followed by favorable consequences, the reward mechanism in the brain is activated, which induces structural changes inside the brain that cause the same behavior to be repeated later, whenever a similar situation arises. Conversely, when a behavior is followed by unfavorable consequences, the brain’s punishment mechanism is activated, inducing structural changes that cause the behavior to be suppressed when similar situations arise in the future.[93] Most organisms studied to date utilize a reward–punishment mechanism: for instance, worms and insects can alter their behavior to seek food sources or to avoid dangers.[94] In vertebrates, the reward-punishment system is implemented by a specific set of brain structures, at the heart of which lie the basal ganglia, a set of interconnected areas at the base of the forebrain.[42] There is substantial evidence that the basal ganglia are the central site at which decisions are made: the basal ganglia exert a sustained inhibitory control over most of the motor systems in the brain; when this inhibition is released, a motor system is permitted to execute the action it is programmed to carry out. Rewards and punishments function by altering the relationship between the inputs that the basal ganglia receive and the decision-signals that are emitted. The reward mechanism is better understood than the punishment mechanism, because its role in drug abuse has caused it to be studied very intensively. Research has shown that the neurotransmitter dopamine plays a central role: addictive drugs such as cocaine, amphetamine, and nicotine either cause dopamine levels to rise or cause the effects of dopamine inside the brain to be enhanced.[95] Learning and memory[edit] Almost all animals are capable of modifying their behavior as a result of experience—even the most primitive types of worms. Because behavior is driven by brain activity, changes in behavior must somehow correspond to changes inside the brain. Theorists dating back to Santiago Ramón y Cajal argued that the most plausible explanation is that learning and memory are expressed as changes in the synaptic connections between neurons.[96] Until 1970, however, experimental evidence to support the synaptic plasticity hypothesis was lacking. In 1971 Tim Bliss and Terje Lømo published a paper on a phenomenon now called long-term potentiation: the paper showed clear evidence of activity-induced synaptic changes that lasted for at least several days.[97] Since then technical advances have made these sorts of experiments much easier to carry out, and thousands of studies have been made that have clarified the mechanism of synaptic change, and uncovered other types of activity-driven synaptic change in a variety of brain areas, including the cerebral cortex, hippocampus, basal ganglia, and cerebellum.[98] Neuroscientists currently distinguish several types of learning and memory that are implemented by the brain in distinct ways: • Working memory is the ability of the brain to maintain a temporary representation of information about the task that an animal is currently engaged in. This sort of dynamic memory is thought to be mediated by the formation of cell assemblies—groups of activated neurons that maintain their activity by constantly stimulating one another.[99] • Episodic memory is the ability to remember the details of specific events. This sort of memory can last for a lifetime. Much evidence implicates the hippocampus in playing a crucial role: people with severe damage to the hippocampus sometimes show amnesia, that is, inability to form new long-lasting episodic memories.[100] • Semantic memory is the ability to learn facts and relationships. This sort of memory is probably stored largely in the cerebral cortex, mediated by changes in connections between cells that represent specific types of information.[101] • Instrumental learning is the ability for rewards and punishments to modify behavior. It is implemented by a network of brain areas centered on the basal ganglia.[102] • Motor learning is the ability to refine patterns of body movement by practicing, or more generally by repetition. A number of brain areas are involved, including the premotor cortex,basal ganglia, and especially the cerebellum, which functions as a large memory bank for microadjustments of the parameters of movement.[103] Development[edit] Main article: Neural development Brain of a human embryo in the sixth week of development The brain does not simply grow, but rather develops in an intricately orchestrated sequence of stages.[104] It changes in shape from a simple swelling at the front of the nerve cord in the earliest embryonic stages, to a complex array of areas and connections. Neurons are created in special zones that contain stem cells, and then migrate through the tissue to reach their ultimate locations. Once neurons have positioned themselves, their axons sprout and navigate through the brain, branching and extending as they go, until the tips reach their targets and form synaptic connections. In a number of parts of the nervous system, neurons and synapses are produced in excessive numbers during the early stages, and then the unneeded ones are pruned away.[104] For vertebrates, the early stages of neural development are similar across all species.[104] As the embryo transforms from a round blob of cells into a wormlike structure, a narrow strip of ectoderm running along the midline of the back is induced to become theneural plate, the precursor of the nervous system. The neural plate folds inward to form the neural groove, and then the lips that line the groove merge to enclose the neural tube, a hollow cord of cells with a fluid-filled ventricle at the center. At the front end, the ventricles and cord swell to form three vesicles that are the precursors of the forebrain, midbrain, and hindbrain. At the next stage, the forebrain splits into two vesicles called the telencephalon (which will contain the cerebral cortex, basal ganglia, and related structures) and the diencephalon (which will contain the thalamus and hypothalamus). At about the same time, the hindbrain splits into the metencephalon (which will contain the cerebellum and pons) and the myelencephalon (which will contain the medulla oblongata). Each of these areas contains proliferative zones where neurons and glial cells are generated; the resulting cells then migrate, sometimes for long distances, to their final positions.[104] Once a neuron is in place, it extends dendrites and an axon into the area around it. Axons, because they commonly extend a great distance from the cell body and need to reach specific targets, grow in a particularly complex way. The tip of a growing axon consists of a blob of protoplasm called a growth cone, studded with chemical receptors. These receptors sense the local environment, causing the growth cone to be attracted or repelled by various cellular elements, and thus to be pulled in a particular direction at each point along its path. The result of this pathfinding process is that the growth cone navigates through the brain until it reaches its destination area, where other chemical cues cause it to begin generating synapses. Considering the entire brain, thousands of genes create products that influence axonal pathfinding.[104] The synaptic network that finally emerges is only partly determined by genes, though. In many parts of the brain, axons initially “overgrow”, and then are “pruned” by mechanisms that depend on neural activity.[104] In the projection from the eye to the midbrain, for example, the structure in the adult contains a very precise mapping, connecting each point on the surface of the retina to a corresponding point in a midbrain layer. In the first stages of development, each axon from the retina is guided to the right general vicinity in the midbrain by chemical cues, but then branches very profusely and makes initial contact with a wide swath of midbrain neurons. The retina, before birth, contains special mechanisms that cause it to generate waves of activity that originate spontaneously at a random point and then propagate slowly across the retinal layer. These waves are useful because they cause neighboring neurons to be active at the same time; that is, they produce a neural activity pattern that contains information about the spatial arrangement of the neurons. This information is exploited in the midbrain by a mechanism that causes synapses to weaken, and eventually vanish, if activity in an axon is not followed by activity of the target cell. The result of this sophisticated process is a gradual tuning and tightening of the map, leaving it finally in its precise adult form.[105] Similar things happen in other brain areas: an initial synaptic matrix is generated as a result of genetically determined chemical guidance, but then gradually refined by activity-dependent mechanisms, partly driven by internal dynamics, partly by external sensory inputs. In some cases, as with the retina-midbrain system, activity patterns depend on mechanisms that operate only in the developing brain, and apparently exist solely to guide development.[105] In humans and many other mammals, new neurons are created mainly before birth, and the infant brain contains substantially more neurons than the adult brain.[104] There are, however, a few areas where new neurons continue to be generated throughout life. The two areas for which adult neurogenesis is well established are the olfactory bulb, which is involved in the sense of smell, and the dentate gyrus of the hippocampus, where there is evidence that the new neurons play a role in storing newly acquired memories. With these exceptions, however, the set of neurons that is present in early childhood is the set that is present for life. Glial cells are different: as with most types of cells in the body, they are generated throughout the lifespan.[106] There has long been debate about whether the qualities of mind, personality, and intelligence can be attributed to heredity or to upbringing—this is the nature versus nurturecontroversy.[107] Although many details remain to be settled, neuroscience research has clearly shown that both factors are important. Genes determine the general form of the brain, and genes determine how the brain reacts to experience. Experience, however, is required to refine the matrix of synaptic connections, which in its developed form contains far more information than the genome does. In some respects, all that matters is the presence or absence of experience during critical periods of development.[108] In other respects, the quantity and quality of experience are important; for example, there is substantial evidence that animals raised in enriched environments have thicker cerebral cortices, indicating a higher density of synaptic connections, than animals whose levels of stimulation are restricted.[109] Research[edit] Main article: Neuroscience Human subject with EEG recording electrodes arranged around his head The Human Brain Project is a large scientific research project, starting in 2013, which aims to simulate the complete human brain. The field of neuroscience encompasses all approaches that seek to understand the brain and the rest of the nervous system.[7] Psychology seeks to understand mind and behavior, and neurology is the medical discipline that diagnoses and treats diseases of the nervous system. The brain is also the most important organ studied in psychiatry, the branch of medicine that works to study, prevent, and treat mental disorders.[110] Cognitive science seeks to unify neuroscience and psychology with other fields that concern themselves with the brain, such as computer science (artificial intelligence and similar fields) and philosophy.[111] The oldest method of studying the brain is anatomical, and until the middle of the 20th century, much of the progress in neuroscience came from the development of better cell stains and better microscopes. Neuroanatomists study the large-scale structure of the brain as well as the microscopic structure of neurons and their components, especially synapses. Among other tools, they employ a plethora of stains that reveal neural structure, chemistry, and connectivity. In recent years, the development of immunostaining techniques has allowed investigation of neurons that express specific sets of genes. Also, functional neuroanatomy uses medical imaging techniques to correlate variations in human brain structure with differences in cognition or behavior.[112] Neurophysiologists study the chemical, pharmacological, and electrical properties of the brain: their primary tools are drugs and recording devices. Thousands of experimentally developed drugs affect the nervous system, some in highly specific ways. Recordings of brain activity can be made using electrodes, either glued to the scalp as in EEG studies, or implanted inside the brains of animals for extracellular recordings, which can detect action potentials generated by individual neurons.[113] Because the brain does not contain pain receptors, it is possible using these techniques to record brain activity from animals that are awake and behaving without causing distress. The same techniques have occasionally been used to study brain activity in human patients suffering from intractable epilepsy, in cases where there was a medical necessity to implant electrodes to localize the brain area responsible for epileptic seizures.[114] Functional imaging techniques such as functional magnetic resonance imaging are also used to study brain activity; these techniques have mainly been used with human subjects, because they require a conscious subject to remain motionless for long periods of time, but they have the great advantage of being noninvasive.[115] Design of an experiment in which brain activity from a monkey was used to control a robotic arm[116] Another approach to brain function is to examine the consequences of damage to specific brain areas. Even though it is protected by the skull and meninges, surrounded by cerebrospinal fluid, and isolated from the bloodstream by the blood–brain barrier, the delicate nature of the brain makes it vulnerable to numerous diseases and several types of damage. In humans, the effects of strokes and other types of brain damage have been a key source of information about brain function. Because there is no ability to experimentally control the nature of the damage, however, this information is often difficult to interpret. In animal studies, most commonly involving rats, it is possible to use electrodes or locally injected chemicals to produce precise patterns of damage and then examine the consequences for behavior.[117] Computational neuroscience encompasses two approaches: first, the use of computers to study the brain; second, the study of how brains perform computation. On one hand, it is possible to write a computer program to simulate the operation of a group of neurons by making use of systems of equations that describe their electrochemical activity; such simulations are known asbiologically realistic neural networks. On the other hand, it is possible to study algorithms for neural computation by simulating, or mathematically analyzing, the operations of simplified “units” that have some of the properties of neurons but abstract out much of their biological complexity. The computational functions of the brain are studied both by computer scientists and neuroscientists.[118] Recent years have seen increasing applications of genetic and genomic techniques to the study of the brain.[119] The most common subjects are mice, because of the availability of technical tools. It is now possible with relative ease to “knock out” or mutate a wide variety of genes, and then examine the effects on brain function. More sophisticated approaches are also being used: for example, using Cre-Lox recombination it is possible to activate or deactivate genes in specific parts of the brain, at specific times.[119] History[edit] Illustration by René Descartes of how the brain implements a reflex response See also: History of neuroscience Early philosophers were divided as to whether the seat of the soul lies in the brain or heart. Aristotle favored the heart, and thought that the function of the brain was merely to cool the blood. Democritus, the inventor of the atomic theory of matter, argued for a three-part soul, with intellect in the head, emotion in the heart, and lust near the liver.[120] Hippocrates, the “father of medicine”, came down unequivocally in favor of the brain. In his treatise on epilepsy he wrote: Men ought to know that from nothing else but the brain come joys, delights, laughter and sports, and sorrows, griefs, despondency, and lamentations. … And by the same organ we become mad and delirious, and fears and terrors assail us, some by night, and some by day, and dreams and untimely wanderings, and cares that are not suitable, and ignorance of present circumstances, desuetude, and unskillfulness. All these things we endure from the brain, when it is not healthy… Hippocrates, On the Sacred Disease[2] Andreas Vesalius’ Fabrica, published in 1543, showing the base of the human brain, including optic chiasma,cerebellum, olfactory bulbs, etc. The Roman physician Galen also argued for the importance of the brain, and theorized in some depth about how it might work. Galen traced out the anatomical relationships among brain, nerves, and muscles, demonstrating that all muscles in the body are connected to the brain through a branching network of nerves. He postulated that nerves activate muscles mechanically by carrying a mysterious substance he calledpneumata psychikon, usually translated as “animal spirits”.[120] Galen’s ideas were widely known during the Middle Ages, but not much further progress came until the Renaissance, when detailed anatomical study resumed, combined with the theoretical speculations of René Descartes and those who followed him. Descartes, like Galen, thought of the nervous system in hydraulic terms. He believed that the highest cognitive functions are carried out by a non-physical res cogitans, but that the majority of behaviors of humans, and all behaviors of animals, could be explained mechanistically.[121] The first real progress toward a modern understanding of nervous function, though, came from the investigations of Luigi Galvani, who discovered that a shock of static electricity applied to an exposed nerve of a dead frog could cause its leg to contract. Since that time, each major advance in understanding has followed more or less directly from the development of a new technique of investigation. Until the early years of the 20th century, the most important advances were derived from new methods for staining cells.[122] Particularly critical was the invention of the Golgi stain, which (when correctly used) stains only a small fraction of neurons, but stains them in their entirety, including cell body, dendrites, and axon. Without such a stain, brain tissue under a microscope appears as an impenetrable tangle of protoplasmic fibers, in which it is impossible to determine any structure. In the hands of Camillo Golgi, and especially of the Spanish neuroanatomist Santiago Ramón y Cajal, the new stain revealed hundreds of distinct types of neurons, each with its own unique dendritic structure and pattern of connectivity.[123] Drawing by Santiago Ramón y Cajal of two types of Golgi-stained neurons from the cerebellum of a pigeon In the first half of the 20th century, advances in electronics enabled investigation of the electrical properties of nerve cells, culminating in work byAlan Hodgkin, Andrew Huxley, and others on the biophysics of the action potential, and the work of Bernard Katz and others on the electrochemistry of the synapse.[124] These studies complemented the anatomical picture with a conception of the brain as a dynamic entity. Reflecting the new understanding, in 1942 Charles Sherrington visualized the workings of the brain waking from sleep: The great topmost sheet of the mass, that where hardly a light had twinkled or moved, becomes now a sparkling field of rhythmic flashing points with trains of traveling sparks hurrying hither and thither. The brain is waking and with it the mind is returning. It is as if the Milky Way entered upon some cosmic dance. Swiftly the head mass becomes an enchanted loom where millions of flashing shuttles weave a dissolving pattern, always a meaningful pattern though never an abiding one; a shifting harmony of subpatterns. —Sherrington, 1942, Man on his Nature[125] In the second half of the 20th century, developments in chemistry, electron microscopy, genetics, computer science, functional brain imaging, and other fields progressively opened new windows into brain structure and function. In the United States, the 1990s were officially designated as the “Decade of the Brain” to commemorate advances made in brain research, and to promote funding for such research.[126] In the 21st century, these trends have continued, and several new approaches have come into prominence, including multielectrode recording, which allows the activity of many brain cells to be recorded all at the same time;[127] genetic engineering, which allows molecular components of the brain to be altered experimentally;[119] and genomics, which allows variations in brain structure to be correlated with variations in DNAproperties.[128] See also[edit] • Brain–computer interface • List of neuroscience databases • Neuroplasticity • Outline of neuroscience • The brain as food References[edit] 1. 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The Neurology of Consciousness: Cognitive Neuroscience and Neuropathology. Academic Press. pp. 31–42. ISBN 978-0-12-374168-4. 116. Jump up^ Carmena, JM et al. (2003). “Learning to Control a Brain–Machine Interface for Reaching and Grasping by Primates”.PLoS Biology 1 (2): 193–208.doi:10.1371/journal.pbio.0000042. PMC 261882.PMID 14624244. 117. Jump up^ Kolb, B; Whishaw, I (2008). “Ch. 1”. Fundamentals of Human Neuropsychology. Macmillan. ISBN 978-0-7167-9586-5. 118. Jump up^ Abbott, LF; Dayan, P (2001). “Preface”. Theoretical Neuroscience: Computational and Mathematical Modeling of Neural Systems. MIT Press. ISBN 978-0-262-54185-5. 119. ^ Jump up to:a b c Tonegawa, S; Nakazawa, K; Wilson, MA (2003). “Genetic neuroscience of mammalian learning and memory”. Philosophical Transactions of the Royal Society B 358 (1432): 787–795. doi:10.1098/rstb.2002.1243.PMC 1693163. PMID 12740125. 120. ^ Jump up to:a b Finger, S (2001). Origins of Neuroscience. Oxford University Press. pp. 14–15. ISBN 978-0-19-514694-3. 121. Jump up^ Finger, S (2001). Origins of Neuroscience. Oxford University Press. pp. 193–195. ISBN 978-0-19-514694-3. 122. Jump up^ Bloom, FE (1975). Schmidt FO, Worden FG, Swazey JP, Adelman G, ed. The Neurosciences, Paths of Discovery. MIT Press. p. 211. ISBN 978-0-262-23072-8. 123. Jump up^ Shepherd, GM (1991). “Ch.1 : Introduction and Overview”.Foundations of the Neuron Doctrine. Oxford University Press. ISBN 978-0-19-506491-9. 124. Jump up^ Piccolino, M (2002). “Fifty years of the Hodgkin-Huxley era”. Trends in Neurosciences 25 (11): 552–553.doi:10.1016/S0166-2236(02)02276-2. PMID 12392928. 125. Jump up^ Sherrington, CS (1942). Man on his nature. Cambridge University Press. p. 178. ISBN 978-0-8385-7701-1. 126. Jump up^ Jones, EG; Mendell, LM (1999). “Assessing the Decade of the Brain”. Science 284 (5415): 739.doi:10.1126/science.284.5415.739. PMID 10336393. 127. Jump up^ Buzsáki, G (2004). “Large-scale recording of neuronal ensembles”. 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By using this site, you agree to the Terms of Use and Privacy Policy. Wikipedia® is a registered trademark of the Wikimedia Foundation, Inc., a non-profit organization. • Privacy policy • About Wikipedia • Disclaimers • Contact Wikipedia • Developers • Mobile view • • Our Mind Mind From Wikipedia, the free encyclopedia For other uses, see Mind (disambiguation). A phrenological mapping[1] of thebrain. Phrenology was among the first attempts to correlate mental functions with specific parts of the brain. René Descartes’ illustration ofmind/body dualism. Descartes believed inputs are passed on by the sensory organs to the epiphysis in the brain and from there to the immaterial spirit.[2] A mind /ˈmaɪnd/ is the set of cognitive faculties that enables consciousness, perception, thinking, judgement, and memory—a characteristic of humans, but which also may apply to other life forms.[3][4] A lengthy tradition of inquiries in philosophy, religion, psychology and cognitive science has sought to develop an understanding of what mind is and what are its distinguishing properties. The main questions regarding the nature of mind is its relation to the physical brain and nervous system – a question which is often framed as the Mind-body problem, which considers whether mind is somehow separate from physical existence (dualism and idealism[5]), deriving from and reducible to physical phenomena such as neurological processes (physicalism), or whether the mind is identical with the brain or some activity of the brain.[6] Another question concerns which types of beings are capable of having minds, for example whether mind is exclusive to humans, possessed also by some or all animals, by all living things, or whether mind can also be a property of some types of man-made machines. Whatever its relation to the physical body it is generally agreed that mind is that which enables a being to have subjective awareness and intentionality towards their environment, to perceive and respond to stimuli with some kind of agency, and to have consciousness, including thinking and feeling.[3][7] Important philosophers of mind include Plato, Descartes, Leibniz, Kant, Martin Heidegger, John Searle, Daniel Dennett and many others. The description and definition is also a part of psychology where psychologists such as Sigmund Freud and William James have developed influential theories about the nature of the human mind. In the late 20th and early 21st centuries the field of cognitive science emerged and developed many varied approaches to the description of mind and its related phenomena. The possibility of non-human minds is also explored in the field of artificial intelligence, which works closely in relation with cybernetics and information theory to understand the ways in which human mental phenomena can be replicated by machines. The concept of mind is understood in many different ways by many different cultural and religious traditions. Some see mind as a property exclusive to humans whereas others ascribe properties of mind to non-living entities (e.g. panpsychism and animism), to animals and to deities. Some of the earliest recorded speculations linked mind (sometimes described as identical with soul or spirit) to theories concerning both life after death, and cosmological and natural order, for example in the doctrines ofZoroaster, the Buddha, Plato, Aristotle, and other ancient Greek, Indian and, later, Islamic and medieval European philosophers. Contents [hide] • 1 Etymology • 2 Definitions • 3 Mental faculties • 4 Mental content o 4.1 Memetics • 5 Relation to the brain • 6 Evolutionary history of the human mind • 7 Philosophy of mind o 7.1 Mind/body perspectives • 8 Scientific study o 8.1 Neuroscience o 8.2 Cognitive Science o 8.3 Psychology • 9 Mental health • 10 Non-human minds o 10.1 Animal intelligence o 10.2 Artificial intelligence • 11 In religion o 11.1 Buddhism o 11.2 Mortality of the mind • 12 In pseudoscience o 12.1 Parapsychology • 13 See also • 14 References • 15 External links Etymology[edit] The original meaning of Old English gemynd was the faculty of memory, not of thought in general. Hence call to mind, come to mind, keep in mind, to have mind of, etc. Old English had other words to express “mind”, such as hyge “mind, spirit”. The meaning of “memory” is shared with Old Norse, which has munr. The word is originally from a PIE verbal root *men-, meaning “to think, remember”, whence also Latin mens “mind”, Sanskrit manas “mind” and Greek μένος “mind, courage, anger”. The generalization of mind to include all mental faculties, thought, volition, feeling and memory, gradually develops over the 14th and 15th centuries.[8] Definitions[edit] This section does not cite any references or sources. Please help improve this section by adding citations to reliable sources. Unsourced material may be challenged and removed. (May 2012) Which attributes make up the mind is much debated. Some psychologists argue that only the “higher” intellectual functions constitute mind, particularly reason and memory. In this view the emotions—love,hate, fear, joy—are more primitive or subjective in nature and should be seen as different from the mind as such. Others argue that various rational and emotional states cannot be so separated, that they are of the same nature and origin, and should therefore be considered all part of what we call the mind. In popular usage mind is frequently synonymous with thought: the private conversation with ourselves that we carry on “inside our heads.” Thus we “make up our minds,” “change our minds” or are “of two minds” about something. One of the key attributes of the mind in this sense is that it is a private sphere to which no one but the owner has access. No one else can “know our mind.” They can only interpret what we consciously or unconsciously communicate. Mental faculties[edit] See also: Nous, Reason, Modularity of mind, and Mental process Broadly speaking, mental faculties are the various functions of the mind, or things the mind can “do”. Thought is a mental act that allows humans to make sense of things in the world, and to represent and interpret them in ways that are significant, or which accord with their needs, attachments, goals, commitments, plans, ends, desires, etc. Thinking involves the symbolic or semiotic mediation of ideas or data, as when we form concepts, engage in problem solving, reasoning and making decisions. Words that refer to similar concepts and processes include deliberation, cognition, ideation, discourse and imagination. Thinking is sometimes described as a “higher” cognitive function and the analysis of thinking processes is a part of cognitive psychology. It is also deeply connected with our capacity to make and use tools; to understand cause and effect; to recognize patterns of significance; to comprehend and disclose unique contexts of experience or activity; and to respond to the world in a meaningful way. Memory is the ability to preserve, retain, and subsequently recall, knowledge, information or experience. Although memory has traditionally been a persistent theme in philosophy, the late nineteenth and early twentieth centuries also saw the study of memory emerge as a subject of inquiry within the paradigms of cognitive psychology. In recent decades, it has become one of the pillars of a new branch of science called cognitive neuroscience, a marriage between cognitive psychology and neuroscience. Imagination is the activity of generating or evoking novel situations, images, ideas or other qualia in the mind. It is a characteristically subjective activity, rather than a direct or passive experience. The term is technically used in psychology for the process of reviving in the mind percepts of objects formerly given in sense perception. Since this use of the term conflicts with that of ordinary language, some psychologists have preferred to describe this process as “imaging” or “imagery” or to speak of it as “reproductive” as opposed to “productive” or “constructive” imagination. Things that are imagined are said to be seen in the “mind’s eye”. Among the many practical functions of imagination are the ability to project possible futures (or histories), to “see” things from another’s perspective, and to change the way something is perceived, including to make decisions to respond to, or enact, what is imagined. Consciousness in mammals (this includes humans) is an aspect of the mind generally thought to comprise qualities such as subjectivity, sentience, and the ability to perceive the relationship between oneselfand one’s environment. It is a subject of much research in philosophy of mind, psychology, neuroscience, and cognitive science. Some philosophers divide consciousness into phenomenal consciousness, which is subjective experience itself, and access consciousness, which refers to the global availability of information to processing systems in the brain.[9] Phenomenal consciousness has many different experienced qualities, often referred to as qualia. Phenomenal consciousness is usually consciousness of something or about something, a property known as intentionality in philosophy of mind. Mental content[edit] This section does not cite any references or sources. Please help improve this section by adding citations to reliable sources. Unsourced material may be challenged and removed. (May 2013) Mental contents are those items that are thought of as being “in” the mind, and capable of being formed and manipulated by mental processes and faculties. Examples include thoughts, concepts, memories,emotions, percepts and intentions. Philosophical theories of mental content include internalism, externalism, representationalism and intentionality. Memetics[edit] Memetics is a theory of mental content based on an analogy with Darwinian evolution, which was originated by Richard Dawkins and Douglas Hofstadter in the 1980s. It is an evolutionary model of culturalinformation transfer. A meme, analogous to a gene, is an idea, belief, pattern of behaviour (etc.) which is “hosted” in one or more individual minds, and which can reproduce itself from mind to mind. Thus what would otherwise be regarded as one individual influencing another to adopt a belief is seen memetically as a meme reproducing itself. As with genetics, particularly under Dawkins’s interpretation, a meme’s success may be due its contribution to the effectiveness of its host (i.e., the meme is a useful, beneficial idea), or may be “selfish”, in which case it could be considered a “virus of the mind”. Relation to the brain[edit] See also: Cognitive science In animals, the brain, or encephalon (Greek for “in the head”), is the control center of the central nervous system, responsible for thought. In most animals, the brain is located in the head, protected by the skulland close to the primary sensory apparatus of vision, hearing, equilibrioception, taste and olfaction. While all vertebrates have a brain, most invertebrates have either a centralized brain or collections of individual ganglia. Primitive animals such as sponges do not have a brain at all. Brains can be extremely complex. For example, the human brain contains more than 100 billion neurons, each linked to as many as 10,000 others.[10][11] Understanding the relationship between the brain and the mind – mind-body problem is one of the central issues in the history of philosophy – is a challenging problem both philosophically and scientifically.[12]There are three major philosophical schools of thought concerning the answer: dualism, materialism, and idealism. Dualism holds that the mind exists independently of the brain;[13] materialism holds that mental phenomena are identical to neuronal phenomena;[14] and idealism holds that only mental phenomena exist.[14] Through most of history many philosophers found it inconceivable that cognition could be implemented by a physical substance such as brain tissue (that is neurons and synapses).[15] Descartes, who thought extensively about mind-brain relationships, found it possible to explain reflexes and other simple behaviors in mechanistic terms, although he did not believe that complex thought, and language in particular, could be explained by reference to the physical brain alone.[16] The most straightforward scientific evidence that there is a strong relationship between the physical brain matter and the mind is the impact physical alterations to the brain have on the mind, such as withtraumatic brain injury and psychoactive drug use.[17] Philosopher Patricia Churchland notes that this drug-mind interaction indicates an intimate connection between the brain and the mind.[18] In addition to the philosophical questions, the relationship between mind and brain involves a number of scientific questions, including understanding the relationship between mental activity and brain activity, the exact mechanisms by which drugs influence cognition, and the neural correlates of consciousness. Evolutionary history of the human mind[edit] The evolution of human intelligence refers to a set of theories that attempt to explain how human intelligence has evolved. The question is closely tied to the evolution of the human brain, and to the emergence of human language. The timeline of human evolution spans some 7 million years, from the separation of the Pan genus until the emergence of behavioral modernity by 50,000 years ago. Of this timeline, the first 3 million years concern Sahelanthropus, the following 2 million concern Australopithecus, while the final 2 million span the history of actual human species (the Paleolithic). Many traits of human intelligence, such as empathy, theory of mind, mourning, ritual, and the use of symbols and tools, are already apparent in great apes although in lesser sophistication than in humans. There is a debate between supporters of the idea of a sudden emergence of intelligence, or “Great leap forward” and those of a gradual or continuum hypothesis. Theories of the evolution of intelligence include: • Robin Dunbar’s social brain hypothesis[19] • Geoffrey Miller’s sexual selection hypothesis[20] • The ecological dominance-social competition (EDSC)[21] explained by Mark V. Flinn, David C. Geary and Carol V. Ward based mainly on work by Richard D. Alexander. • The idea of intelligence as a signal of good health and resistance to disease. • The Group selection theory contends that organism characteristics that provide benefits to a group (clan, tribe, or larger population) can evolve despite individual disadvantages such as those cited above. • The idea that intelligence is connected with nutrition, and thereby with status[22] A higher IQ could be a signal that an individual comes from and lives in a physical and social environment where nutrition levels are high, and vice versa. Philosophy of mind[edit] Main article: Philosophy of mind Philosophy of mind is the branch of philosophy that studies the nature of the mind, mental events, mental functions, mental properties, consciousness and their relationship to the physical body. The mind-body problem, i.e. the relationship of the mind to the body, is commonly seen as the central issue in philosophy of mind, although there are other issues concerning the nature of the mind that do not involve its relation to the physical body.[23] José Manuel Rodriguez Delgado writes, “In present popular usage, soul and mind are not clearly differentiated and some people, more or less consciously, still feel that the soul, and perhaps the mind, may enter or leave the body as independent entities.”[24] Dualism and monism are the two major schools of thought that attempt to resolve the mind-body problem. Dualism is the position that mind and body are in some way separate from each other. It can be traced back to Plato,[25] Aristotle[26][27][28] and the Samkhya and Yoga schools of Hindu philosophy,[29] but it was most precisely formulated by René Descartes in the 17th century.[30] Substance dualists argue that the mind is an independently existing substance, whereas Property dualists maintain that the mind is a group of independent properties that emerge from and cannot be reduced to the brain, but that it is not a distinct substance.[31] The 20th century philosopher Martin Heidegger suggested that subjective experience and activity (i.e. the “mind”) cannot be made sense of in terms of Cartesian “substances” that bear “properties” at all (whether the mind itself is thought of as a distinct, separate kind of substance or not). This is because the nature of subjective, qualitative experience is incoherent in terms of – or semanticallyincommensurable with the concept of – substances that bear properties. This is a fundamentally ontological argument.[32] The philosopher of cognitive science Daniel Dennett, for example, argues that there is no such thing as a narrative center called the “mind”, but that instead there is simply a collection of sensory inputs and outputs: different kinds of “software” running in parallel.[33] Psychologist B.F. Skinner argued that the mind is an explanatory fiction that diverts attention from environmental causes of behavior;[34] he considered the mind a “black box” and thought that mental processes may be better conceived of as forms of covert verbal behavior.[35][36] Mind/body perspectives[edit] Monism is the position that mind and body are not physiologically and ontologically distinct kinds of entities. This view was first advocated in Western Philosophy by Parmenides in the 5th Century BC and was later espoused by the 17th Century rationalist Baruch Spinoza.[37] According to Spinoza’s dual-aspect theory, mind and body are two aspects of an underlying reality which he variously described as “Nature” or “God”. • Physicalists argue that only the entities postulated by physical theory exist, and that the mind will eventually be explained in terms of these entities as physical theory continues to evolve. • Idealists maintain that the mind is all that exists and that the external world is either mental itself, or an illusion created by the mind. • Neutral monists adhere to the position that perceived things in the world can be regarded as either physical or mental depending on whether one is interested in their relationship to other things in the world or their relationship to the perceiver. For example, a red spot on a wall is physical in its dependence on the wall and the pigment of which it is made, but it is mental in so far as its perceived redness depends on the workings of the visual system. Unlike dual-aspect theory, neutral monism does not posit a more fundamental substance of which mind and body are aspects. The most common monisms in the 20th and 21st centuries have all been variations of physicalism; these positions include behaviorism, the type identity theory, anomalous monism and functionalism.[38] Many modern philosophers of mind adopt either a reductive or non-reductive physicalist position, maintaining in their different ways that the mind is not something separate from the body.[38] These approaches have been particularly influential in the sciences, e.g. in the fields of sociobiology, computer science, evolutionary psychology and the various neurosciences.[39][40][41][42] Other philosophers, however, adopt a non-physicalist position which challenges the notion that the mind is a purely physical construct. • Reductive physicalists assert that all mental states and properties will eventually be explained by scientific accounts of physiological processes and states.[43][44][45] • Non-reductive physicalists argue that although the brain is all there is to the mind, the predicates and vocabulary used in mental descriptions and explanations are indispensable, and cannot be reduced to the language and lower-level explanations of physical science.[46][47] Continued progress in neuroscience has helped to clarify many of these issues, and its findings strongly support physicalists’ assertions.[48][49] Nevertheless our knowledge is incomplete, and modern philosophers of mind continue to discuss how subjective qualia and the intentional mental states can be naturally explained.[50][51] Scientific study[edit] Simplified diagram of Spaun, a 2.5-million-neuron computational model of the brain. (A) The corresponding physical regions and connections of the human brain. (B)The mental architecture of Spaun.[52] Neuroscience[edit] See also: Cognitive neuroscience and Thought identification Neuroscience studies the nervous system, the physical basis of the mind. At the systems level, neuroscientists investigate how biological neural networks form and physiologically interact to produce mental functions and content such as reflexes, multisensory integration, motor coordination,circadian rhythms, emotional responses, learning, and memory. At a larger scale, efforts in computational neuroscience have developed large-scale models that simulate simple, functioning brains.[52] As of 2012, such models include the thalamus, basal ganglia, prefrontal cortex, motor cortex, andoccipital cortex, and consequentially simulated brains can learn, respond to visual stimuli, coordinate motor responses, form short-term memories, and learn to respond to patterns. Currently, researchers aim to program the hippocampus and limbic system, hypothetically imbuing the simulated mind withlong-term memory and crude emotions.[53] By contrast, affective neuroscience studies the neural mechanisms of personality, emotion, and mood primarily through experimental tasks. Cognitive Science[edit] See also: Cognitive Science This section requires expansion. (May 2013) Cognitive science examines the mental functions that give rise to information processing, termed cognition. These include attention, memory, producing and understanding language, learning, reasoning, problem solving, and decision making. Cognitive science seeks to understand thinking “in terms of representational structures in the mind and computational procedures that operate on those structures”.[54] Psychology[edit] See also: Neuropsychology and Unconscious mind Psychology is the scientific study of human behavior, mental functioning, and experience. As both an academic and applied discipline, Psychology involves the scientific study of mental processes such asperception, cognition, emotion, personality, as well as environmental influences, such as social and cultural influences, and interpersonal relationships, in order to devise theories of human behavior. Psychology also refers to the application of such knowledge to various spheres of human activity, including problems of individuals’ daily lives and the treatment of mental health problems. Psychology differs from the other social sciences (e.g., anthropology, economics, political science, and sociology) due to its focus on experimentation at the scale of the individual, or individuals in small groups as opposed to large groups, institutions or societies. Historically, psychology differed from biology and neuroscience in that it was primarily concerned with mind rather than brain. Modern psychological science incorporates physiological and neurological processes into its conceptions of perception, cognition, behaviour, and mental disorders. Mental health[edit] Main article: Mental health By analogy with the health of the body, one can speak metaphorically of a state of health of the mind, or mental health. Merriam-Webster defines mental health as “A state of emotional and psychological well-being in which an individual is able to use his or her cognitive and emotional capabilities, function in society, and meet the ordinary demands of everyday life.” According to the World Health Organization(WHO), there is no one “official” definition of mental health. Cultural differences, subjective assessments, and competing professional theories all affect how “mental health” is defined. In general, most experts agree that “mental health” and “mental illness” are not opposites. In other words, the absence of a recognized mental disorder is not necessarily an indicator of mental health. One way to think about mental health is by looking at how effectively and successfully a person functions. Feeling capable and competent; being able to handle normal levels of stress, maintaining satisfying relationships, and leading an independent life; and being able to “bounce back,” or recover from difficult situations, are all signs of mental health. Psychotherapy is an interpersonal, relational intervention used by trained psychotherapists to aid clients in problems of living. This usually includes increasing individual sense of well-being and reducing subjective discomforting experience. Psychotherapists employ a range of techniques based on experiential relationship building, dialogue, communication and behavior change and that are designed to improve the mental health of a client or patient, or to improve group relationships (such as in a family). Most forms of psychotherapy use only spoken conversation, though some also use various other forms of communication such as the written word, art, drama, narrative story, or therapeutic touch. Psychotherapy occurs within a structured encounter between a trained therapist and client(s). Purposeful, theoretically based psychotherapy began in the 19th century with psychoanalysis; since then, scores of other approaches have been developed and continue to be created. Non-human minds[edit] Animal intelligence[edit] Animal cognition, or cognitive ethology, is the title given to a modern approach to the mental capacities of animals. It has developed out of comparative psychology, but has also been strongly influenced by the approach of ethology, behavioral ecology, and evolutionary psychology. Much of what used to be considered under the title of “animal intelligence” is now thought of under this heading. Animal language acquisition, attempting to discern or understand the degree to which animal cognition can be revealed by linguistics-related study, has been controversial among cognitive linguists. Artificial intelligence[edit] This section needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. (September 2007) Main article: Philosophy of artificial intelligence Computer simulation of the branching architecture of the dendrites of pyramidal neurons.[55] In 1950 Alan M. Turing published “Computing machinery and intelligence” in Mind, in which he proposed that machines could be tested for intelligence using questions and answers. This process is now named the Turing Test. The term Artificial Intelligence (AI) was first used by John McCarthy who considered it to mean “the science and engineering of making intelligent machines”.[56] It can also refer to intelligence as exhibited by an artificial (man-made, non-natural, manufactured) entity. AI is studied in overlapping fields of computer science, psychology, neuroscience and engineering, dealing with intelligent behavior, learning and adaptation and usually developed using customized machines or computers. Research in AI is concerned with producing machines to automate tasks requiring intelligent behavior. Examples include control, planning and scheduling, the ability to answer diagnostic and consumer questions, handwriting, natural language, speech and facial recognition. As such, the study of AI has also become an engineering discipline, focused on providing solutions to real life problems, knowledge mining, software applications, strategy games like computer chess and other video games. One of the biggest limitations of AI is in the domain of actual machine comprehension. Consequentially natural language understanding and connectionism (where behavior of neural networks is investigated) are areas of active research and development. The debate about the nature of the mind is relevant to the development of artificial intelligence. If the mind is indeed a thing separate from or higher than the functioning of the brain, then hypothetically it would be much more difficult to recreate within a machine, if it were possible at all. If, on the other hand, the mind is no more than the aggregated functions of the brain, then it will be possible to create a machine with a recognisable mind (though possibly only with computers much different from today’s), by simple virtue of the fact that such a machine already exists in the form of the human brain. In religion[edit] Many religions associate spiritual qualities to the human mind. These are often tightly connected to their mythology and afterlife. The Indian philosopher-sage Sri Aurobindo attempted to unite the Eastern and Western psychological traditions with his integral psychology, as have many philosophers and New religious movements. Judaismteaches that “moach shalit al halev”, the mind rules the heart. Humans can approach the Divine intellectually, through learning and behaving according to the Divine Will as enclothed in the Torah, and use that deep logical understanding to elicit and guide emotional arousal during prayer. Christianity has tended to see the mind as distinct from the soul (Greek nous) and sometimes further distinguished from the spirit.Western esoteric traditions sometimes refer to a mental body that exists on a plane other than the physical. Hinduism’s various philosophical schools have debated whether the human soul (Sanskrit atman) is distinct from, or identical to, Brahman, the divine reality. Taoism sees the human being as contiguous with natural forces, and the mind as not separate from the body. Confucianism sees the mind, like the body, as inherently perfectible. Buddhism[edit] See also: Buddhism and psychology According to Buddhist philosopher Dharmakirti, the mind has two fundamental qualities: “clarity and knowing”. If something is not those two qualities, it cannot validly be called mind. “Clarity” refers to the fact that mind has no color, shape, size, location, weight, or any other physical characteristic, and that it gives rise to the contents of experience. “Knowing” refers to the fact that mind is aware of the contents of experience, and that, in order to exist, mind must be cognizing an object. You cannot have a mind – whose function is to cognize an object – existing without cognizing an object. For this reason, mind is often described in Buddhism as “that which has contents”.[57] Mind, in Buddhism, is also described as being “space-like” and “illusion-like”. Mind is space-like in the sense that it is not physically obstructive. It has no qualities which would prevent it from existing. Mind is illusion-like in the sense that it is empty of inherent existence. This does not mean it does not exist, it means that it exists in a manner that is counter to our ordinary way of misperceiving how phenomena exist, according to Buddhism. When the mind is itself cognized properly, without misperceiving its mode of existence, it appears to exist like an illusion. There is a big difference however between being “space and illusion” and being “space-like” and “illusion-like”. Mind is not composed of space, it just shares some descriptive similarities to space. Mind is not an illusion, it just shares some descriptive qualities with illusions. Buddhism posits that there is no inherent, unchanging identity (Inherent I, Inherent Me) or phenomena (Ultimate self, inherent self, Atman, Soul, Self-essence, Jiva, Ishvara, humanness essence, etc.) which is the experiencer of our experiences and the agent of our actions. In other words, human beings consist of merely a body and a mind, and nothing extra. Within the body there is no part or set of parts which is – by itself or themselves – the person. Similarly, within the mind there is no part or set of parts which are themselves “the person”. A human being merely consists of five aggregates, or skandhas and nothing else (please see Valid Designation). In the same way, “mind” is what can be validly conceptually labelled onto our mere experience of clarity and knowing. There is not something separate and apart from clarity and knowing which is “mind”, in Buddhism. “Mind” is that part of experience which can be validly referred to as mind by the concept-term “mind”. There is also not “objects out there, mind in here, and experience somewhere in-between”. There is not a third thing called “experience” which exists between the contents of mind and what mind cognizes. There is only the clarity (arising of mere experience: shapes, colors, the components of smell, components of taste, components of sound, components of touch) and nothing else; this means, expressly, that there is not a third thing called “experience” and not a third thing called “experiencer who has the experience”. This is deeply related to “no-self”. Clearly, the experience arises and is known by mind, but there is not a third thing which sits apart from that which is the “real experiencer of the experience”. This is the claim of Buddhism, with regards to mind and the ultimate nature of minds (and persons). Mortality of the mind[edit] Due to the mind-body problem, much interest and debate surround the question of what happens to one’s conscious mind as one’s body dies.[citation needed] According to neuropsychology, all brain function halts permanently upon brain death, and the mind fails to survive brain death and ceases to exist. This permanent loss of consciousness after death is often called “eternal oblivion”. The belief that some spiritual orimmaterial component exists and is preserved after death is described by the term “afterlife”.[citation needed] In pseudoscience[edit] Parapsychology[edit] Parapsychology is the scientific study of certain types of paranormal phenomena, or of phenomena which appear to be paranormal,[58] for instance precognition, telekinesis and telepathy. The term is based on the Greek para (beside/beyond), psyche (soul/mind), and logos (account/explanation) and was coined by psychologist Max Dessoir in or before 1889.[59] J. B. Rhine later popularized “parapsychology” as a replacement for the earlier term “psychical research”, during a shift in methodologies which brought experimental methods to the study of psychic phenomena.[59] Parapsychology is controversial, with many scientists believing that psychic abilities have not been demonstrated to exist.[60][61][62][63][64] The status of parapsychology as a science has also been disputed,[65] with many scientists regarding the discipline as pseudoscience.[66][67][68] See also[edit] • Cognitive sciences • Conscience • Consciousness • Explanatory gap • Hard problem of consciousness • Mental energy • Mind-body problem • Mind at Large • Neural Darwinism • Philosophical zombie • Philosophy of mind • Problem of other minds • Sentience • Skandha • Subjective character of experience • Theory of mind References[edit] 1. Jump up^ Oliver Elbs, Neuro-Esthetics: Mapological foundations and applications (Map 2003), (Munich 2005) 2. Jump up^ Descartes, R. (1641) Meditations on First Philosophy, in The Philosophical Writings of René Descartes, trans. by J. Cottingham, R. Stoothoff and D. Murdoch, Cambridge: Cambridge University Press, 1984, vol. 2, pp. 1-62. 3. ^ Jump up to:a b Dictionary.com, “mind”: “1. (in a human or other conscious being) the element, part, substance, or process that reasons, thinks, feels, wills, perceives, judges, etc.: the processes of the human mind. 2. Psychology. the totality of conscious and unconscious mental processes and activities. 3. intellect or understanding, as distinguished from the faculties of feeling and willing; intelligence.” 4. Jump up^ Google definition, “mind”: “The element of a person that enables them to be aware of the world and their experiences, to think, and to feel; the faculty of consciousness..” [1] 5. Jump up^ Redding, Paul, “Georg Wilhelm Friedrich Hegel”, The Stanford Encyclopedia of Philosophy (Summer 2012 Edition), Edward N. Zalta (ed.), forthcoming. [2][dead link]. See section “2.1 Background: “Idealism” as understood in the German tradition”.[expand reference] 6. Jump up^ Smart, J. J. C., “The Mind/Brain Identity Theory”, The Stanford Encyclopedia of Philosophy (Fall 2011 Edition), Edward N. Zalta (ed.), [3] 7. Jump up^ Oxford American College Dictionary, “mind”: “1. the element of a person that enables them to be aware of the world and their experiences, to think, and to feel; the faculty of consciousness and thought.” 8. Jump up^ OED;etymonline.com 9. Jump up^ Ned Block: On a Confusion about a Function of Consciousness” in: The Behavioral and Brain Sciences, 1995. 10. Jump up^ Whishaw, Bryan Kolb, Ian Q. (2010). An Introduction to Brain and Behavior (3rd ed. ed.). New York: Worth Publishers. p. 72.ISBN 978-0-7167-7691-8. Retrieved 11 May 2012. 11. Jump up^ Sherwood, Lauralee (2011). Fundamentals of Human Physiology (4th ed. ed.). Belmont, CA: Brooks/Cole Cengage Learning. p. 91. ISBN 978-0-8400-6225-3. Retrieved 11 May 2012. 12. 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(1996) “Dualism”, in Samuel Guttenplan (org) A Companion to the Philosophy of Mind, Blackwell, Oxford, 265–7. 32. Jump up^ Hubert Dreyfus, “Critique of Descartes I” (recorded lecture), University of California at Berkeley, September 18, 2007. 33. Jump up^ Dennett, Daniel (1991). Consciousness Explained. Boston, Massachusetts: Little Brown. ISBN 0-316-18065-3. 34. Jump up^ Skinner, B.F. About Behaviorism 1974, page 74–75 35. Jump up^ Skinner, B.F. About Behaviorism, Chapter 7: Thinking 36. Jump up^ A thesis against which Noam Chomsky advanced a considerable polemic. 37. Jump up^ Spinoza, Baruch (1670) Tractatus Theologico-Politicus (A Theologico-Political Treatise). 38. ^ Jump up to:a b Kim, J., “Mind-Body Problem”, Oxford Companion to Philosophy. Ted Honderich (ed.). Oxford:Oxford University Press. 1995. 39. Jump up^ Pinel, J. Psychobiology, (1990) Prentice Hall, Inc. ISBN 88-15-07174-1 40. Jump up^ LeDoux, J. 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Merrill, eds., Art, Mind and Religion Pittsburgh:University of Pittsburgh Press. 48. Jump up^ Farah, Martha J.; Murphy, Nancey (February 2009).”Neuroscience and the Soul”. Science 323 (5918): p. 1168.doi:10.1126/science.323.5918.1168a. Retrieved 20 November 2012. 49. Jump up^ Koch, Christof (July 2009). “Do Not Underestimate Science”.Science 325 (5939): 392. doi:10.1126/science.325_392b. Retrieved 14 November 2012. 50. Jump up^ Dennett, Daniel (1998). The intentional stance. Cambridge, Mass.: MIT Press. ISBN 0-262-54053-3. 51. Jump up^ Searle, John (2001). Intentionality. A Paper on the Philosophy of Mind. Frankfurt a. M.: Nachdr. Suhrkamp. ISBN 3-518-28556-4. 52. ^ Jump up to:a b Eliasmith, Chris; Terrence C. Stewart, Xuan Choo, Trevor Bekolay, Travis DeWolf, Yichuan Tang, Daniel Rasmussen (30 November 2012). “A Large-Scale Model of the Functioning Brain”. Science 338 (6111): 1202–1205.doi:10.1126/science.1225266. Retrieved 13 May 2013. 53. 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California State Board of Education. 1990. 61. Jump up^ Wheeler, J. A. (1979). “Point of View: Drive the Pseudos Out…”.Skeptical Inquirer 3: 12–13. 62. Jump up^ Kurtz, P. (1978). “Is Parapsychology a Science?”. Skeptical Inquirer 3: 14–32. 63. Jump up^ Druckman, D. and Swets, J. A. eds. (1988). Enhancing Human Performance: Issues, Theories and Techniques. National Academy Press, Washington, D.C. p. 22. ISBN 0-309-07465-7. 64. Jump up^ Reuters (5 September 2003). “Telepathy gets academic in Sweden”. CNN. Retrieved 9 March 2009. “Despite decades of experimental research … there is still no proof that gifts such as telepathy and the ability to see the future exist, mainstream scientists say.” 65. Jump up^ Flew, Antony (1982). “Parapsychology: Science or Pseudoscience?”. In Grim, Patrick. Philosophy of Science and the Occult. 66. Jump up^ Cordón, Luis A. (2005). Popular psychology: an encyclopedia. Westport, Conn: Greenwood Press. p. 182. ISBN 0-313-32457-3. “The essential problem is that a large portion of the scientific community, including most research psychologists, regards parapsychology as a pseudoscience, due largely to its failure to move beyond null results in the way science usually does. Ordinarily, when experimental evidence fails repeatedly to support a hypothesis, that hypothesis is abandoned. Within parapsychology, however, more than a century of experimentation has failed even to conclusively demonstrate the mere existence of paranormal phenomenon, yet parapsychologists continue to pursue that elusive goal.” 67. Jump up^ Bunge, Mario (1991). “A skeptic’s beliefs and disbeliefs”. New Ideas in Psychology 9 (2): 131–149. doi:10.1016/0732-118X(91)90017-G. 68. Jump up^ Blitz, David (1991). “The line of demarcation between science and nonscience: The case of psychoanalysis and parapsychology”. New Ideas in Psychology 9 (2): 163–170.doi:10.1016/0732-118X(91)90020-M. External links[edit] Find more about Mind at Wikipedia’s sister projects Definitions and translations from Wiktionary Media from Commons Learning resources from Wikiversity Quotations from Wikiquote Source texts from Wikisource Textbooks from Wikibooks Wikibooks has a book on the topic of: Consciousness studies • C. D. Broad, The Mind and Its Place in Nature, 1925. • ThinkQuest: Think.com, Oracle Education Foundation, Projects | Competition | Library, History of Artificial Intelligence. • Loebner.net, Description by Turing of testing machines for intelligence. • Philosophy portal • Mind and brain portal • Neuroscience portal Spirit Spirit From Wikipedia, the free encyclopedia For other uses, see Spirit (disambiguation). This article needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. (June 2009) Theodor von Holst, Bertalda, Assailed by Spirits, c.1830 The English word spirit (from Latin spiritus “breath”) has many differing meanings and connotations, most of them relating to a non-corporeal substance contrasted with the material body. The word spirit is often used metaphysically to refer to the consciousness or personality. The notions of a person’s spirit and soul often also overlap, as both contrast with body and both are understood as surviving the bodily death in religion and occultism,[1] and “spirit” can also have the sense of “ghost”, i.e. a manifestation of the spirit of a deceased person. The term may also refer to any incorporeal or immaterial being, such as demons or deities, in Christianity specifically the Holy Spirit (though with a capital “S”) experienced by the disciples at Pentecost. Contents [hide] • 1 Etymology • 2 Metaphysical and metaphorical uses o 2.1 Metaphysical contexts o 2.2 Metaphorical usage • 3 Related concepts in other languages • 4 See also • 5 References • 6 Further reading Etymology[edit] The English word spirit comes from the Latin spiritus, meaning “breath”, but also “spirit, soul, courage, vigor”, ultimately from a Proto-Indo-European *(s)peis. It is distinguished from Latin anima, “soul” (which nonetheless also derives from an Indo-European root meaning “to breathe”, earliest form *h2enh1- [2]). In Greek, this distinction exists between pneuma (πνευμα), “breath, motile air, spirit,” and psykhē (ψυχη), “soul”[3] (even though the latter term, ψῡχή = psykhē/psūkhē, is also from an Indo-European root meaning “to breathe”: *bhes-, zero grade *bhs- devoicing in proto-Greek to *phs-, resulting in historical-period Greek ps- in psūkhein, “to breathe”, whence psūkhē, “spirit”, “soul”[4]). The word “spirit” came into Middle English via Old French. The distinction between soul and spirit also developed in the Abrahamic religions: Arabic nafs (نفس) opposite rúħ (روح); Hebrew neshama (נְשָׁמָהnəšâmâh) or nephesh (in Hebrew neshama comes from the root NŠM or “breath”) opposite ruach (רוּחַ rûaħ). (Note, however, that in Semitic just as in Indo-European, this dichotomy has not always been as neat historically as it has come to be taken over a long period of development: Both נֶ֫פֶשׁ (root נפשׁ) and רוּחַ (root רוח), as well as cognate words in various Semitic languages, including Arabic, also preserve meanings involving misc. air phenomena: “breath”, “wind”, and even “odour”.[5][6][7]) Metaphysical and metaphorical uses[edit] English-speakers use the word “spirit” in two related contexts, one metaphysical and the other metaphorical. Metaphysical contexts[edit] In metaphysical terms, “spirit” has acquired a number of meanings: • An incorporeal but ubiquitous, non-quantifiable substance or energy present individually in all living things. Unlike the concept of souls (often regarded as eternal and sometimes believed to pre-exist the body) a spirit develops and grows as an integral aspect of a living being.[8] This concept of the individual spirit occurs commonly in animism. Note the distinction between this concept of spirit and that of the pre-existing or eternal soul: belief in souls occurs specifically and far less commonly, particularly in traditional societies. One might more properly term this type/aspect of spirit “life” (bios in Greek) or “aether” rather than “spirit” (pneuma in Greek). • A daemon sprite, or especially a ghost. People usually conceive of a ghost as a wandering spirit from a being no longer living, having survived the death of the body yet maintaining at least vestiges of mindand of consciousness. • In religion and spirituality, the respiration of a human has for obvious reasons become seen as strongly linked with the very occurrence of life. A similar significance has become attached to human blood. Spirit, in this sense, means the thing that separates a living body from a corpse—and usually implies intelligence, consciousness, and sentience. • Latter-day Saint prophet Joseph Smith Jr. taught that the concept of spirit as incorporeal or without substance was incorrect: “There is no such thing as immaterial matter. All spirit is matter, but it is more fine or pure, and can only be discerned by purer eyes.”[9] • In some Native American spiritual traditions the Great Spirit or Wakan Tanka is a term for the Supreme Being. • Various forms of animism, such as Japan’s Shinto and African traditional religion, focus on invisible beings that represent or connect with plants, animals (sometimes called “Animal Fathers)”, or landforms(kami)[citation needed]: translators usually employ the English word “spirit” when trying to express the idea of such entities. • Individual spirits envisaged as interconnected with all other spirits and with “The Spirit” (singular and capitalized). This concept relates to theories of a unified spirituality, to universal consciousness and to some concepts of Deity. In this scenario all separate “spirits”, when connected, form a greater unity, the Spirit, which has an identity separate from its elements plus a consciousness and intellect greater than its elements; an ultimate, unified, non-dual awareness or force of life combining or transcending all individual units of consciousness. The experience of such a connection can become a primary basis for spiritual belief. The term spirit occurs in this sense in (to name but a few) Anthroposophy, Aurobindo, A Course In Miracles, Hegel, Ken Wilber, and Meher Baba (though in his teachings, “spirits” are onlyapparently separate from each other and from “The Spirit.”)[10] In this use, the term seems conceptually identical to Plotinus’s “The One” and Friedrich Schelling’s “Absolute”. Similarly, according to thepanentheistic/pantheistic view, Spirit equates to essence that can manifest itself as mind/soul through any level in pantheistic hierarchy/holarchy, such as through a mind/soul of a single cell (with very primitive, elemental consciousness), or through a human or animal mind/soul (with consciousness on a level of organic synergy of an individual human/animal), or through a (superior) mind/soul with synergetically extremely complex/sophisticated consciousness of whole galaxies involving all sub-levels, all emanating (since the superior mind/soul operates non-dimensionally, or trans-dimensionally) from the one Spirit. • Christian theology can use the term “Spirit” to describe God, or aspects of God — as in the “Holy Spirit”, referring to a Triune God (Trinity)(cf Gospel of Matthew 28:19). • “Spirit” forms a central concept in pneumatology (note that pneumatology studies “pneuma” (Greek for “spirit”) not “psyche” (Greek for “soul”) — as studied in psychology). • Christian Science uses “Spirit” as one of the seven synonyms for God, as in: “Principle; Mind; Soul; Spirit; Life; Truth; Love”[11] • Harmonism reserves the term “spirit” for those that collectively control and influence an individual from the realm of the mind. Metaphorical usage[edit] The metaphorical use of the term likewise groups several related meanings: • The loyalty and feeling of inclusion in the social history or collective essence of an institution or group, such as in school spirit or esprit de corps. • A closely related meaning refers to the worldview of a person, place, or time, as in “The Declaration of Independence was written in the spirit of John Locke and his notions of liberty”, or the term zeitgeist, meaning “spirit of the age”. • As a synonym for “vivacity” as in “She performed the piece with spirit” or “She put up a spirited defense”. • The underlying intention of a text as distinguished from its literal meaning, especially in law; see Letter and spirit of the law • As a term for alcoholic beverages. • In mysticism: existence in unity with Godhead. Soul may also equate with spirit, but the soul involves certain individual human consciousness, while spirit comes from beyond that. Compare the psychological teaching of Al-Ghazali. See soul and ghost and spiritual for related discussions. Related concepts in other languages[edit] Similar concepts in other languages include Greek pneuma and Sanskrit akasha/atman[3] (see also prana). Some languages use a word for “spirit” often closely related (if not synonymous) to “mind”. Examples include the German Geist (related to the English word “ghost”) or the French ‘l’esprit’. English versions of the Bible most commonly translate the Hebrew word “ruach” (רוח; “wind”) as “the spirit”, whose essence is divine[12] (see Holy Spirit and ruach hakodesh). Alternatively, Hebrew texts commonly use the word nephesh. Kabbalists regard nephesh as one of the five parts of the Jewish soul, where nephesh (animal) refers to the physical being and its animal instincts. Similarly, Scandinavian languages, Baltic languages, Slavic languages and the Chinese language (qi) use the words for “breath” to express concepts similar to “the spirit”.[3] See also[edit] Spirituality portal Look up spirit in Wiktionary, the free dictionary. Wikiquote has a collection of quotations related to: Spirit • Angel • Astral Projection • Ba (Egyptian soul) • Brahman • Daemon (mythology) • Deva • Ekam • Ka • Jinn • Monster • Non-physical entity • Soul dualism • Spiritism • Spirit world References[edit] 1. Jump up^ OED “spirit 2.a.: The soul of a person, as commended to God, or passing out of the body, in the moment of death.” 2. Jump up^ anə1-. Watkins, Calvert, The American Heritage® Dictionary of Indo-European Roots, second edition. Boston: Houghton-Mifflin Co., 2000, p. 4. Also available online athttp://web.archive.org/web/20071208010420/http://www.bartleby.com/61/roots/IE17.html. [Note that ə1, ə2, ə3 as used by Watkins are fully equivalent notational variants for h1, h2, h3, respectively, which are more widely used for the same Proto-Indo-European laryngeal segments.] 3. ^ Jump up to:a b c François 2008, p.187-197. 4. Jump up^ bhes-2. Watkins, Calvert, The American Heritage® Dictionary of Indo-European Roots, second edition. Boston: Houghton-Mifflin Co., 2000, p. 11. Also available online athttp://web.archive.org/web/20071208011042/http://www.bartleby.com/61/roots/IE60.html 5. Jump up^ Koehler, L., Baumgartner, W., Richardson, M. E. J., & Stamm, J. J. (1999). The Hebrew and Aramaic lexicon of the Old Testament (electronic ed.) (711). Leiden; New York: E.J. Brill. 6. Jump up^ Brown, F., Driver, S. R., & Briggs, C. A. (2000). Enhanced Brown-Driver-Briggs Hebrew and English Lexicon (electronic ed.) (659). Oak Harbor, WA: Logos Research Systems. (N.B. Corresponds closely to printed editions.) 7. Jump up^ Brown, F., Driver, S. R., & Briggs, C. A. (2000). Enhanced Brown-Driver-Briggs Hebrew and English Lexicon (electronic ed.) (924ff.). Oak Harbor, WA: Logos Research Systems. (N.B. Corresponds closely to printed editions.) 8. Jump up^ http://www.patheos.com/Library/Mormonism/Beliefs/Human-Nature-and-the-Purpose-of-Existence.html 9. Jump up^ Doctrine and Covenants 131:7 10. Jump up^ Kalchuri, Bhau: Meher Prabhu: Lord Meher, Volume Eighteen, Manifestation, Inc., 1986, p. 5937. 11. Jump up^ Eddy, Mary Baker (1875). “Glossary” (TXT). Science and Health With Key to the Scriptures. p. 587. Retrieved 2009-03-11. “GOD. The great I AM; the all-knowing, all-seeing, all-acting, all-wise, all-loving, and eternal; Principle; Mind; Soul; Spirit; Life; Truth; Love; all substance; intelligence.” — “Glossary” entry for “GOD”. 12. Jump up^ RUACH: Spirit or Wind or ??? at Biblical Heritage Center Further reading[edit] • François, Alexandre (2008), “Semantic maps and the typology of colexification: Intertwining polysemous networks across languages”, in Vanhove, Martine, From Polysemy to Semantic change: Towards a Typology of Lexical Semantic Associations, Studies in Language Companion Series 106, Amsterdam, New York: Benjamins, pp. 163–215 • Baba, Meher (1967). Discourses. San Francisco: Sufism Reoriented. ISBN 1-880619-09-1. Categories: • Deities, spirits, and mythic beings • Ghosts • Religious philosophical concepts • Spirituality • Vitalism Navigation menu • Create account • Log in • Article • Talk • Read • Edit • View history • Main page • Contents • Featured content • Current events • Random article • Donate to Wikipedia • Wikimedia Shop Interaction • Help • About Wikipedia • Community portal • Recent changes • Contact page Tools Print/export Languages • العربية • Azərbaycanca • Български • Català • Čeština • ChiShona • Dansk • Deutsch • Eesti • Español • Euskara • Français • Furlan • Gàidhlig • 한국어 • हिन्दी • Hrvatski • Ido • Italiano • Kiswahili • Lietuvių • नेपाल भाषा • 日本語 • Norsk bokmål • Norsk nynorsk • Polski • Português • Română • Русский • Shqip • Sicilianu • Simple English • Slovenčina • Словѣ́ньскъ / ⰔⰎⰑⰂⰡⰐⰠⰔⰍⰟ • Српски / srpski • Suomi • Svenska • ไทย • Türkçe • Українська • 粵語 • 中文 • Edit links Definition of Divinity Divinity: The Synergy of our body, mind and Spirit in Diversity. From Wikipedia, the free encyclopedia “Divine” redirects here. For other uses, see Divine (disambiguation) or Divinity (disambiguation) Elizabeth I and the three Goddesses Juno,Minerva & Venus. In religious terms, divinity is the state of things that come from a supernatural power or deity, such as a god, or spirit beings, and are therefore regarded assacred and holy.[1][2][3] Such things are regarded as “divine” due to their transcendental origins, and/or because their attributes or qualities are superior or supreme relative to things of the Earth.[1] Divine things are regarded as eternal and based in truth,[1] while material things are regarded as ephemeral and based inillusion. Such things that may qualify as “divine” are apparitions, visions, prophecies, miracles, and in some views also the soul, or more general things like resurrection, immortality, grace, and salvation. Otherwise what is or is not divine may be loosely defined, as it is used by different belief systems. The root of the word “divine” is literally “godlike” (from the Latin deus, cf. Dyaus, closely related to Greek zeus, div in Persian and deva in Sanskrit), but the use varies significantly depending on which deity is being discussed. This article outlines the major distinctions in the conventional use of the terms. For specific related academic terms, see Divinity (academic discipline), or Divine (Anglican). Contents [hide] • 1 Usages o 1.1 Entity o 1.2 Divine force or power o 1.3 Mortals • 1.3.1 Latter-Day Saints o 1.4 Christianity and New Testament references • 2 See also • 3 Notes and references Usages[edit] Divinity as a quality has two distinct usages: • Divine force or power – powers or forces that are universal, or transcend human capacities • Divinity applied to mortals – qualities of individuals who are considered to have some special access or relationship to the divine. Overlap occurs between these usages because deities or godlike entities are often identical with and/or identified by the powers and forces that are credited to them — in many cases a deity is merely a power or force personified — and these powers and forces may then be extended or granted to mortal individuals. For instance, Jehovah is closely associated with storms and thunder throughout much of the Old Testament. He is said to speak in thunder, and thunder is seen as a token of his anger. This power was then extended to prophets like Moses and Samuel, who caused thunderous storms to rain down on their enemies. (See Exodus 9:23 and 1 Samuel 12:18.) Divinity always carries connotations of goodness, beauty, beneficence, justice, and other positive, pro-social attributes. In monotheistic faiths there is an equivalent cohort of malefic supranormal beings and powers, such as demons, devils, afreet, etc., which are not conventionally referred to as divine; demonic is often used instead. Pantheistic and polytheistic faiths make no such distinction; gods and other beings of transcendent power often have complex, ignoble, or even irrational motivations for their acts. Note that while the terms demon and demonic are used in monotheistic faiths as antonyms to divine, they are in fact derived from the Greek word daimón (δαίμων), which itself translates as divinity. There are three distinct usages of divinity and divine in religious discourse: Entity[edit] Main article: Deity In monotheistic faiths, the word divinity is often used to refer to the singular God central to that faith. Often the word takes the definite article and is capitalized — “the Divinity” — as though it were a proper name or definitive honorific. Divine — capitalized — may be used as an adjective to refer to the manifestations of such a Divinity or its powers: e.g. “basking in the Divine presence…” The terms divinity and divine — uncapitalized, and lacking the definite article — are sometimes used as to denote ‘god(s)[4] or certain other beings and entities which fall short of godhood but lie outside the human realm. These include (by no means an exhaustive list): Divine force or power[edit] As previously noted, divinities are closely related to the transcendent force(s) or power(s) credited to them,[5] so much so that in some cases the powers or forces may themselves be invoked independently. This leads to the second usage of the word divine (and a less common usage of divinity): to refer to the operation of transcendent power in the world. In its most direct form, the operation of transcendent power implies some form of divine intervention. For pan- and polytheistic faiths this usually implies the direct action of one god or another on the course of human events. In Greek legend, for instance, it was Poseidon (god of the sea) who raised the storms which blew Odysseus’ craft off course on his return journey, and Japanese tradition holds that a god-sent wind saved them from Mongol invasion. Prayers or propitiations are often offered to specific gods of pantheisms to garner favorable interventions in particular enterprises: e.g. safe journeys, success in war, or a season of bountiful crops. Many faiths around the world — from Japanese Shinto and Chinese traditional religion, to certain African practices and the faiths derived from those in the Caribbean, to Native American beliefs — hold that ancestral or household spirits offer daily protection and blessings. In monotheistic religions, divine intervention may take very direct forms: miracles, visions, or intercessions by blessed figures. Transcendent force or power may also operate through more subtle and indirect paths. Monotheistic faiths generally support some version of divine providence, which acknowledges that the divinity of the faith has a profound but unknowable plan always unfolding in the world. Unforeseeable, overwhelming, or seemingly unjust events are often thrown on ‘the will of the Divine’, in deferences like the Muslim inshallah(‘as God wills it’) and Christian ‘God works in mysterious ways’. Often such faiths hold out the possibility of divine retribution as well, where the divinity will unexpectedly bring evil-doers to justice through the conventional workings of the world; from the subtle redressing of minor personal wrongs, to such large-scale havoc as the destruction of Sodom and Gomorrah or the biblical Great Flood. Other faiths are even more subtle: the doctrine of karma shared by Buddhism and Hinduism is a divine law similar to divine retribution but without the connotation of punishment: our acts, good or bad, intentional or unintentional, reflect back on us as part of the natural working of the universe. Philosophical Taoism also proposes a transcendent operant principle — transliterated in English as tao or dao, meaning ‘the way’ — which is neither an entity or a being per se, but reflects the natural ongoing process of the world. Modern western mysticism and new age philosophy often use the term ‘the Divine’ as a noun in this latter sense: a non-specific principle and/or being that gives rise to the world, and acts as the source or wellspring of life. In these latter cases the faiths do not promote deference, as happens in monotheisms; rather each suggests a path of action that will bring the practitioner into conformance with the divine law: ahimsa — ‘no harm’ — for Buddhist and Hindu faiths; de or te — ‘virtuous action’ — in daoism; and any of numerous practices of peace and love in new age thinking. Mortals[edit] Main article: apotheosis In the third usage, extensions of divinity and divine power are credited to living, mortal individuals. Political leaders are known to have claimed actual divinity in certain early societies — the ancient Egyptian Pharaohs being the premier case — taking a role as objects of worship and being credited with superhuman status and powers. More commonly, and more pertinent to recent history, leaders merely claim some form of divine mandate, suggesting that their rule is in accordance with the will of God. The doctrine of the divine right of kings was introduced as late as the 17th century, proposing that kings rule by divine decree; Japanese Emperors ruled by divine mandate until the inception of the Japanese constitution after World War II Less politically, most faiths have any number of people that are believed to have been touched by divine forces: saints, prophets, heroes, oracles, martyrs, and enlightened beings, among others. Saint Francis of Assisi, in Catholicism, is said to have received instruction directly from God and it is believed that he grants plenary indulgence to all who confess their sins and visit his chapel on the appropriate day. In Greek mythology, Achilles’ mother bathed him in the river Styx to give him immortality, and Hercules — as the son of Zeus — inherited near-godlike powers. In religious Taoism, Lao Tsu is venerated as a saint with his own powers. Various individuals in the Buddhist faith, beginning with Siddhartha, are considered to be enlightened, and in religious forms of Buddhism they are credited with divine powers. Muhammadand Christ, in their respective traditions, are each said to have performed divine miracles. In general, mortals with divine qualities are carefully distinguished from the deity or deities in their religion’s main pantheon.[6] Even the Christian faith, which generally holds Christ to be identical to God, distinguishes between God the Father and Christ the begotten Son.[7] There are, however, certain esoteric and mystical schools of thought, present in many faiths — Sufis in Islam, Gnostics in Christianity, Advaitan Hindus, Zen Buddhists, as well as several non-specific perspectives developed in new age philosophy — which hold that all humans are in essence divine, or unified with the Divine in a non-trivial way. Such divinity, in these faiths, would express itself naturally if it were not obscured by the social and physical worlds we live in; it needs to be brought to the fore through appropriate spiritual practices.[8] Latter-Day Saints[edit] Main article: God in Mormonism According to The Church of Jesus Christ of Latter-day Saints, such spiritual practices are, in and of themselves, inspired by promptings from the light of Christ or the Holy Spirit that are communications with an individual’s divine essence or spirit that is linked directly to God through pre-existence as his offspring. Belief in a divine potential of humankind is taught by The Church of Jesus Christ of Latter-day Saints (LDS). The LDS teaches that there is a pre-mortal stage of human existence, known as pre-existence, during which pre-mortal human spirits, called spirit children, are able to make choices that influence their upcoming fully mortal existence as a direct result of the individual spirit’s choices regarding truth, love and faith. Spirit children come into existence out of “intelligences”. “Intelligences” are eternal forms of energy or matter existing in a less progressed form than God. (See Joseph Smith’s King Follett discourse.) According to the LDS church, Christ’s unwavering ability to obey truth, perceive light, and act in perfect love and faith, distinguishes his pre-mortal existence from the pre-mortal existence of the other spirit beings who were in the presence of the “Eternal Father”. Christ’s behaviour during his “spirit child” phase serves to explain why he is considered to be God-like. The God-like quality ascribed to Jesus explains why he had a greater capacity to suffer more than mortal man could suffer; thus he could endure the anguish and incomprehensible pain of the atonement. The LDS belief is that Christ’s divinity qualified him to return to the presence of God after his death and resurrection. By means of the atonement and his offering of divine grace to humankind, Christ provided access to divinity for humankind. A divine being is filled with perfect love, and desires to share these qualities because of the joy they bring to each individual soul. Christianity and New Testament references[edit] In traditional Christian theology, the concept and nature of divinity always has its source ultimately from God himself. It’s the state or quality of being divine, in Hebrew, the terms would usually be “el”, “elohim”, and in Greek usually “theos”, or “theias”. The divinity in the Bible is considered the Godhead itself, or God in general. Or it may have reference to a deity.[9] Even angels in the Psalms are considered divine orelohim, as spirit beings, in God’s form. Redeemed Christians, when taken to heaven as immortalized born-again believers, according to Biblical verses, are said to partake of the “divine nature”. (Psalm 8:5; Hebrews 2:9; 2 Peter 1:4) And the term can denote Godlike nature or character. In the Christian Greek Scriptures of the Bible, the Greek word θεῖον (theion) in the Douay Version, is translated as “divinity”. Examples are below: • Acts 17:29 “Being therefore the offspring of God, we must not suppose the divinity to be like unto gold, or silver, or stone, the graving of art, and device of man.” • Romans 1:20 “For the invisible things of him, from the creation of the world, are clearly seen, being understood by the things that are made; his eternal power also, and divinity: so that they are inexcusable.” • Revelation 5:12 “Saying with a loud voice: The Lamb that was slain is worthy to receive power, and divinity, and wisdom, and strength, and honour, and glory, and benediction.” The word translated as either “deity”, “Godhead”, or “divinity” in the Greek New Testament is also the Greek word θεότητος (theotētos), and the one Verse that contains it is this: Colossians 2:9 “Quia in ipso inhabitat omnis plenitudo divinitatis [divinity] corporaliter.” (Vulgate) “For in him dwelleth all the fulness of the Godhead bodily.” (KJV) “Because it is in him that all the fullness of the divine quality dwells bodily.” (NWT) “For in him all the fullness of deity lives in bodily form.” (NET) “For the full content of divine nature lives in Christ.” (TEV) The word “divine” in the New Testament is the Greek word θείας (theias), and is the adjective form of “divinity”. Biblical examples from the King James Bible are below: • 2 Peter 1:3 “According as his divine power hath given unto us all things that pertain unto life and godliness, through the knowledge of him that hath called us to glory and virtue.” • 2 Peter 1:4 “Whereby are given unto us exceeding great and precious promises: that by these ye might be partakers of the divine nature, having escaped the corruption that is in the world through lust.” See also[edit] • Catholic Concept of the Divine • Christology • Deity • Ho’oponopono (Morrnah section) • List of deities • Theosis Notes and references[edit] 1. ^ Jump up to:a b c Wiktionary: “divine (comparative more divine, superlative most divine) 1) of or pertaining to a god 2) eternal, holy, or otherwise supernatural 3) of superhuman or surpassing excellence 4) beautiful, heavenly 2. Jump up^ http://dictionary.reference.com/browse/divine 3. Jump up^ Merriam Webster: http://www.merriam-webster.com/dictionary/divine 4. Jump up^ See, for example “The Great Stag: A Sumerian Divinity” by Bobula Ida (Yearbook of Ancient and Medieval History 1953) 5. Jump up^ note Augustine’s argument that divinity is not a quality of God, but that “God is […] Divinity itself” (Nature and Grace, part I, question 3, article 3) “Whether God is the Same as His Essence or Nature” 6. Jump up^ This is sometimes a controversial issue, however; see [1], for example, for a discussion of the status of the Japanese emperor. 7. Jump up^ See, for example, “The Divinity of Alpha’s Jesus” by Peterson & McDonald (Media Spotlight 25:4, 2002) 8. Jump up^ See, for example, “Twelve Signs of Your Awakening Divinity” by Geoffrey Hoppe and Tobias 9. Jump up^ divinity – The Free Dictionary. [show] • v • t • e Theism [show] • v • t • e Theological thought [show] • v • t • e Theology Categories: • Theology • Religious belief and doctrine • Philosophy of religion • Gods Our Body The Acid-Base Balance of our body Acid–base homeostasis is the part of human homeostasis concerning the proper balance between acids and bases, also called body pH. The body is very sensitive to its pH level, so strong mechanisms exist to maintain it. Outside the acceptable range of pH, proteins are denatured and digested, enzymes lose their ability to function, and death may occur. Contents [hide] • 1 Mechanism • 2 Imbalance • 3 References • 4 External links Mechanism[edit] The body’s acid–base balance is normally tightly regulated, keeping the arterial blood pH between 7.38 and 7.42.[1] Several buffering agents that reversibly bind hydrogen ions and impede any change in pH exist. Extracellular buffers include bicarbonate and ammonia, whereas proteins and phosphate act as intracellular buffers. The bicarbonate buffering system is especially key, as carbon dioxide (CO2) can be shifted through carbonic acid (H2CO3) to hydrogen ions and bicarbonate (HCO−3) as shown below.[2] Acid–base imbalances that overcome the buffer system can be compensated in the short term by changing the rate of ventilation. This alters the concentration of carbon dioxide in the blood, shifting the above reaction according to Le Chatelier’s principle, which in turn alters the pH. For instance, if the blood pH drops too low (acidemia), the body will compensate by increasing breathing[3] thereby expelling CO2, and shifting the above reaction to the left such that fewer hydrogen ions are free; thus the pH will rise back to normal. For alkalemia, the opposite occurs. The kidneys are slower to compensate, but renal physiology has several powerful mechanisms to control pH by the excretion of excess acid or base. In response to acidosis, tubular cells reabsorb more bicarbonate from the tubular fluid, collecting duct cells secrete more hydrogen and generate more bicarbonate, and ammoniagenesis leads to increased formation of the NH3 buffer. In responses to alkalosis, the kidney may excrete more bicarbonate by decreasing hydrogen ion secretion from the tubular epithelial cells, and lowering rates of glutamine metabolism and ammonium excretion. Imbalance[edit] Acid–base imbalance occurs when a significant insult causes the blood pH to shift out of the normal range (7.35 to 7.45). In the fetus, the normal range differs based on which umbilical vessel is sampled (umbilical vein pH is normally 7.25 to 7.45; umbilical artery pH is normally 7.18 to 7.38).[4] An excess of acid in the blood is called acidemia and an excess of base is called alkalemia. The process that causes the imbalance is classified based on the etiology of the disturbance (respiratory or metabolic) and the direction of change in pH (acidosis or alkalosis). There are four basic processes: metabolic acidosis, respiratory acidosis, metabolic alkalosis, and respiratory alkalosis. One or a combination may occur at any given time. References[edit] 1. Jump up^ MedlinePlus Encyclopedia Blood gases 2. Jump up^ Garrett, Reginald H.; Grisham, Charles M (2010). Biochemistry. Cengage Learning. p. 43. ISBN 978-0-495-10935-8. 3. Jump up^ MedlinePlus Encyclopedia Metabolic acidosis 4. Jump up^ Yeomans, ER; Hauth, JC; Gilstrap, LC III; Strickland DM (1985). “Umbilical cord pH, PCO2, and bicarbonate following uncomplicated term vaginal deliveries (146 infants)”. Am J Obstet Gynecol 151: 798–800.PMID 3919587. External links[edit] • Stewart’s original text at acidbase.org • On-line text at AnaesthesiaMCQ.com • Overview at kumc.edu • Tutorial at acid-base.com • Online acid–base physiology text • Diagnoses at lakesidepress.com • Interpretation at nda.ox.ac.uk

5 thoughts on “Universal Divine Living in Diversity- The Universe, Body, Mind and Spirit Connection

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