In physics and cosmology, the anthropic principle is an umbrella term for various dissimilar attempts to explain the structure of the universe by way of coincidentally balanced features that are necessary and relevant to the existence on Earth of biochemistry, carbon-based life, and eventually human beings to observe such a universe. The common (and "weak") form of the anthropic principle is a truism or tautology that begins with the observation that the universe appears surprisingly hospitable to the emergence of life, particularly complex multicellular life, that can make such an observation and concludes with that premise that in only such a fine-tuned universe can such living observers be. Given the extreme simplicity of the universe at the start of the Big Bang, the friendliness of the universe to complex structures such as galaxies, planetary systems, and biology is unexpected by any normal model of turbulence driven structuring that science has been able to derive. Physics (from the Greek, (phúsis), nature and (phusiké), knowledge of nature) is the science concerned with the discovery and understanding of the fundamental laws which govern matter, energy, space, and time. ... // Cosmology, from the Greek: κοσμολογία (cosmologia, κόσμος (cosmos) order + λογια (logia) discourse) is the study of the Universe in its totality, and by extension, humanitys place in it. ... The expression umbrella term means a word that provides a superset or grouping of related concepts. ... The universe from a speculative theoretical physicists point of view can be described as the sum of all matter and energy that exists and the space-time in which they are located and in which all events occur or could occur. ... Carbon forms the backbone of biology for all life on Earth. ... A truism is a claim that is so obvious or self-evident as to be hardly worth mentioning, except as a reminder or as a rhetorical or literary device. ... Within the study of logic, a tautology is a statement containing more than one sub-statement, that is true regardless of the truth values of its parts. ... The deepest visible-light image of the cosmos. ... According to the Big Bang, the universe emerged from an extremely dense and hot state (bottom). ...

The idea evolved from the so-called "Dicke's coincidence", and has subsequently been reinforced by the discovery of many more anthropic coincidences since Robert Dicke first noted that the evolution of the universe is not random, but is coincidentally constrained by biological factors ^[1] that require that the age of the universe had to be roughly this "golden-age" ^[2]. Much younger, and there would not have been time for sufficient interstellar levels of carbon to build up by nucleosynthesis, but much older, and the golden age of main sequence stars and stable planetary systems would have already come to an end. Robert Henry Dicke (May 6, 1916 – March 4, 1997) was an American physicist and astrophysicist. ... The age of the universe, according to the Big Bang theory, is defined as the largest possible value of proper time integrated along a time-like curve from the Earth at the present epoch back to the Big Bang. The time that has elapsed on a hypothetical clock which has...

The anthropic principle also acts as a convenient category for physical and cosmological reasoning that takes into account the existence of a biosphere on Earth in an essential way. Attempts to invoke the "anthropic principle" to develop scientific explanations has led to more than a little confusion and controversy.

Much of the controversy arises from the perception that some versions of the Principle re-introduce the Argument from Design for the existence of God. A teleological argument (or a design argument) is an argument for the existence of God or a creator based on perceived evidence of order, purpose, design and/or direction in nature. ... This article does not cite its references or sources. ...

More anthropic coincidences

The relevant anthropic coincidences [2] occur in complete unexpected contrast to all attempts to model the evolution of the universe, and have been "unfolding" since the moment of the big bang, ranging in magnitude from our local ecosystem, all the way up the ladder to the near-perfectly balanced, "flat" structuring of the universe, itself, so the universe appears to be surprisingly hospitable to the emergence of life at a specific time and "location" [3] in the history of the universe, particularly, complex multicellular carbon-based life.

Given the extreme simplicity of the universe at the start of the Big Bang, the friendliness of the universe to complex structures such as galaxies, planetary systems, and biology is unexpected by any normal model of turbulence driven structuring that we have been able to derive. It is therefore possible to use anthropic reasoning to make testable predictions about the features of the observed universe from the average of extreme opposing runaway tendencies that are known to be inherent to the anthropic coincidences, as well as to choose from a multiverse of different configurations, in lieu of a more viable stability mechanism. According to the Big Bang, the universe emerged from an extremely dense and hot state (bottom). ...

Carbon-based life is either a likely and thus necessary outcome of the observed structure and stability of the universe, or it is a part of an engine of creation that favors such outcomes. So a proven identification of a stability mechanism may be expected to settle this question of causality, which means that the strong anthropic principle (SAP) can be further supported or falsified. If falsified, only the weak anthropic principle (WAP), essentially a tautology, remains. Carbon forms the backbone of biology for all life on Earth. ... The philosophical concept of causality, the principles of causes, or causation, the working of causes, refers to the set of all particular causal or cause-and-effect relations. ... Tautology refers to a use of redundant language in speech or writing, or, put simply, saying the same thing twice. Within the study of logic, a tautology is a statement that is true by its own definition. ...

Attempts to invoke the "principle" to develop scientific explanations have led to more than a little confusion, and controversy.

Origin of the anthropic cosmological principle

The first to employ the phrase "anthropic principle" appears to have been the theoretical astrophysicist Brandon Carter, in his contribution to a 1973 Kraków symposium titled Confrontation of Cosmological Theories with Observational Data honouring Copernicus's 500th birthday. Carter articulated the Anthropic Principle as an ecological correction, so called, of what is now called the Cosmological Principle. This Principle extends the principle of relativity so as to require that all observers experience the same laws of physics uniformly throughout the universe. Hence at any given time, the universe will be both homogeneous and isotropic, (in 3-D space). This defines a non-applicable principle of mediocrity, one precluding the existence of a mechanism favoring any particular time and location for the appearance of carbon-based life as we know it. Brandon Carter is a theoretical physicist, most famous for his work on the properties of black holes and for introducing the anthropic principle. ... Wawel Hill. ... Symposium originally referred to a drinking party (the Greek verb sympotein means to drink together) but has since come to refer to any academic conference, whether or not drinking takes place. ... Nicolaus Copernicus (in Latin; Polish Mikołaj Kopernik, German Nikolaus Kopernikus - February 19, 1473 – May 24, 1543) was a Polish astronomer, mathematician and economist who developed a heliocentric (Sun-centered) theory of the solar system in a form detailed enough to make it scientifically useful. ... The mediocrity principle is the notion in the philosophy of science that there is nothing special about Earth, and by implication the human race. ...

Anthropic principle was as well formulated in already the 1940's, in relation to relativistic cosmology and physics constants, by Abraham Zelmanov^[3], a prominent scientist in the General Theory of Relativity and cosmology. // Cosmology, from the Greek: κοσμολογία (cosmologia, κόσμος (cosmos) order + λογια (logia) discourse) is the study of the Universe in its totality, and by extension, humanitys place in it. ... Image:Ab zelmanov. ... General relativity (GR) or general relativity theory (GRT) is the theory of gravitation published by Albert Einstein in 1915. ... // Cosmology, from the Greek: κοσμολογία (cosmologia, κόσμος (cosmos) order + λογια (logia) discourse) is the study of the Universe in its totality, and by extension, humanitys place in it. ...

Copernicus argued that the Earth is not the centre of the solar system, but Carter noted that pure cosmological extensions of this idea are what he called the anticentrist dogma, that led to cosmological formulations like the Perfect Cosmological Principle, which does not result from the evolutionary physics that derives the cosmic coincidences and the otherwise unexplained large scale structuring of the universe that becomes absurdly apparent with the cosmological constant problem. This vexing problem is why the Anthropic Principle has acquired a following among String Theorists trying to choose the correct vacuum solution from the landscape, since no other stability mechanism explaining why this is so has been proposed. Carter's symposium paper, "Large Number Coincidences and the Anthropic Principle in Cosmology," included the statement: "Although our situation is not necessarily central, it is inevitably privileged to some extent".^[4] The Perfect Cosmological Principle is an extension of the Cosmological Principle stating that the Universe is not only homogeneous and isotropic in space, but also in time. ... The cosmological constant (usually denoted by the Greek capital letter lambda: Λ) was proposed by Albert Einstein as part of his theory of general relativity to achieve a stationary universe. ... The string theory landscape or anthropic landscape refers to the large number of different false vacua in string theory. ...

Carter was not the first to invoke some form of the anthropic principle. For instance, Robert H. Dicke wrote in 1957 that: "The age of the Universe 'now' is not random but conditioned by biological factors ... [changes in the values of the fundamental constants of physics] would preclude the existence of man to consider the problem."^[5] Alfred Russel Wallace anticipated the weak anthropic principle as long ago as 1903: "Such a vast and complex universe as that which we know exists around us, may have been absolutely required ... in order to produce a world that should be precisely adapted in every detail for the orderly development of life culminating in man."^[6] The WAP is perhaps even echoed by Karl Marx's theory of historical materialism: "The first premise of all human history is, of course, the existence of living human individuals. Thus the first fact to be established is the physical organisation of these individuals and their consequent relation to the rest of nature."^[7] Robert Henry Dicke (May 6, 1916 – March 4, 1997) was an American experimental physicist, who made important contributions to the fields of astrophysics, atomic physics, cosmology and gravity. ... Alfred Russel Wallace Alfred Russel Wallace, OM, FRS (January 8, 1823 – November 7, 1913) was a British naturalist, explorer, geographer, anthropologist and biologist. ... Karl Heinrich Marx (May 5, 1818, Trier, Germany – March 14, 1883, London) was a German philosopher, political economist, and revolutionary. ... Historical materialism is the methodological approach to the study of society, economics and history which was first articulated by Karl Marx (1818-1883), although Marx himself never used the term. ...

Observational evidence

The observed values of the dimensionless parameters (such as the fine-structure constant) that govern the four forces of nature are finely balanced. A slight increase in the strong nuclear force would bind the dineutron and the diproton and all the hydrogen in the early universe would have been converted to helium. There would be no water or long-lived stable stars that are essential for the development of life. Similar relationships are evident in each of the four force strengths. If they are modified sufficiently the universe's structure and capacity for life is greatly affected. The fine-structure constant or Sommerfeld fine-structure constant, usually denoted , is the fundamental physical constant characterizing the strength of the electromagnetic interaction. ... A fundamental interaction is a mechanism by which particles interact with each other, and which cannot be explained by another more fundamental interaction. ... The deepest visible-light image of the cosmos. ... The strong nuclear force or strong interaction (also called color force or colour force) is a fundamental force of nature which affects only quarks and antiquarks, and is mediated by gluons in a similar fashion to how the electromagnetic force is mediated by photons. ...

Variants of the anthropic principle

Proponents of the anthropic principle submit that the universe appears "fine-tuned" so as to permit life as we know it to exist, because were the universe not fine tuned in this fashion, human beings would not exist and hence could not observe the universe. The deepest visible-light image of the cosmos. ... For other uses, see Life (disambiguation), Lives (disambiguation) or Living (disambiguation), Living Things (disambiguation). ...

Barrow and Tipler (1986) propose three important variants of the Anthropic Principle, Weak, Strong, and Final, listed below in order of increasing strength:

• Weak anthropic principle (WAP): "The observed values of all physical and cosmological quantities are not equally probable but they take on values restricted by the requirement that there exist sites where carbon-based life can evolve and by the requirements that the Universe be old enough for it to have already done so."^[8]
  • The Merriam-Webster dictionary defines WAP as conditions that are observed in the universe must allow the observer to exist.

If any of the fundamental physical constants were sufficiently different, then life as we know it would not be possible and no one would be around to contemplate the universe we live in. Barrow and Tipler, among others, argue that the WAP explains the fundamental physical constants, such as the fine structure constant, the number of dimensions in the universe, and the cosmological constant. Carbon forms the backbone of biology for all life on Earth. ... In physics, fundamental physical constants are, in the strictest sense, physical constants that are independent of systems of units and hence are dimensionless numbers. ... In physics, fundamental physical constants are physical constants that are independent of systems of units and are in general dimensionless numbers. ... The fine-structure constant or Sommerfeld fine-structure constant, usually denoted , is the fundamental physical constant characterizing the strength of the electromagnetic interaction. ... In physics, spacetime is a mathematical model that combines three-dimensional space and one-dimensional time into a single construct called the space-time continuum, in which time plays the role of the 4th dimension. ... The cosmological constant (usually denoted by the Greek capital letter lambda: Λ) was proposed by Albert Einstein as part of his theory of general relativity to achieve a stationary universe. ...

From Roger Penrose: Sir Roger Penrose, OM, FRS (born 8 August 1931) is an English mathematical physicist and Emeritus Rouse Ball Professor of Mathematics at the Mathematical Institute, University of Oxford and Emeritus Fellow of Wadham College. ...

Is there something special about our particular location in the universe, either in space or in time? These are the kinds of question that are addressed by what has become known as the anthropic principle. This principle has many forms. (See Barrow and Tipler 1986.) The most clearly acceptable of these addresses merely the spatiotemporal location of conscious (or 'intelligent') life in the universe. This is the weak anthropic principle. The argument can be used to explain why the conditions happen to be just right for the existence of (intelligent) life on the earth at the present time. For if they were not just right, then we should not have found ourselves to be here now, but somewhere else, at some other appropriate time. This principle was used very effectively by Brandon Carter and Robert Dicke to resolve an issue that had puzzled physicists for a good many years. The issue concerned various striking numerical relations that are observed to hold between the physical constants (the gravitational constant, the mass of the proton, the age of the universe, etc.). A puzzling aspect of this was that some of the relations hold only at the present epoch in the earth's history, so we appear, coincidentally, to be living at a very special time (give or take a few million years!). This was later explained, by Carter and Dicke, by the fact that this epoch coincided with the lifetime of what are called main-sequence stars, such as the sun. At any other epoch, so the argument ran, there would be no intelligent life around in order to measure the physical constants in question-so the coincidence had to hold, simply because there would be intelligent life around only at the particular time that the coincidence did hold!

—The Emperor's New Mind The Emperors New Mind: Concerning Computers, Minds and The Laws of Physics is a 1989 book by mathematical physicist Roger Penrose. ...

• Strong anthropic principle (SAP): "The Universe must have those properties which allow life to develop within it at some stage in its history."^[9] Barrow and Tipler then propose three elaborations of the SAP:^[10]
  • "There exists one possible Universe 'designed' with the goal of generating and sustaining 'observers.' " This can be seen as simply the classic design argument dressed in the garb of contemporary cosmology. It implies that the purpose of the universe is to give rise to intelligent life, with the laws of nature and their fundamental constants set to ensure that life as we know it will emerge and evolve. ("The Rejection of Pascal's Wager")
  • "Observers are necessary to bring the Universe into being." Barrow and Tipler believe that this can be validly inferred from quantum mechanics.
  • "An ensemble of other different universes is necessary for the existence of our Universe." Thus Barrow and Tipler sympathize with the many worlds interpretation of quantum mechanics.

• Final anthropic principle (FAP): "Intelligent information-processing must come into existence in the Universe, and, once it comes into existence, it will never die out."^[11]

In his review of Barrow and Tipler in the New York Review of Books', Martin Gardner ridiculed the FAP by quoting the last two sentences of their book: The deepest visible-light image of the cosmos. ... In physics, fundamental physical constants are physical constants that are independent of systems of units and are in general dimensionless numbers. ... Blaise Pascal argued that it is a better bet to believe in God than not to do so. ... Fig. ... This article may be too technical for most readers to understand. ... Fig. ... The final anthropic principle (FAP) is defined by physicists John D. Barrow and Frank J. Tiplers 1986 book The Anthropic Cosmological Principle as a generalization of the anthropic principle as follows: Final anthropic principle (FAP): Intelligent information-processing must come into existence in the Universe, and, once it comes... Martin Gardner (b. ...

• Completely ridiculous anthropic principle (CRAP): "At the instant the Omega Point is reached, life will have gained control of all matter and forces not only in a single universe, but in all universes whose existence is logically possible; life will have spread into all spatial regions in all universes which could logically exist, and will have stored an infinite amount of information, including all bits of knowledge which it is logically possible to know. And this is the end."^[12]

In Carter's original definition, the WAP referred only to certain "cosmological" parameters, namely our space/time location within the universe, and not to values of the fundamental physical constants, which would fall under the SAP according to him. He also refers to "observers" rather than "carbon-based life". This ambiguity is a reason for the ongoing disagreements about the status of the various Anthropic Principles. Omega point is a term invented by French Jesuit Pierre Teilhard de Chardin to describe the ultimate maximum level of complexity-consciousness, considered by him the aim towards which consciousness evolves. ...

Proponents of intelligent design claim support from the SAP. On the other hand, the existence of the multiverse or alternate universes is hypothesized for other reasons and the WAP provides a plausible explanation for the fine tuning of our universe. Assuming there are possible universes capable of supporting intelligent life, some actual universes must do so and ours clearly is one of those. However, alternatives to intelligent design are not limited to hypothesizing the existence of alternate universes, and some advocates of evolution claim support from the Anthropic Principle. On the other hand, Ikeda and Jefferys (2006) argue that the Anthropic Principle as conventionally stated actually undermines intelligent design.^[13] This is discussed in more detail in fine-tuned universe. Intelligent design (ID) is the concept that certain features of the universe and of living things are best explained by an intelligent cause, not an undirected process such as natural selection. ... A multiverse (or meta-universe) is the hypothetical set of multiple possible universes (including our universe) that together comprise all of physical reality. ... A multiverse (or meta-universe) is the hypothetical set of multiple possible universes (including our universe) that together comprise all of physical reality. ... This article is about evolution in biology. ... The deepest visible-light image of the cosmos. ...

The Anthropic Cosmological Principle

The most thorough extant study of the anthropic principle is the controversial book The Anthropic Cosmological Principle by John D. Barrow, a cosmologist, and Frank J. Tipler, a mathematical physicist. This book contains an extensive review of the relevant history of ideas, because its authors believe that the anthropic principle has important antecedents in the notions of intelligent design, the philosophies of Fichte, Hegel, Bergson, and Alfred North Whitehead, and the omega point cosmology of Teilhard de Chardin. Barrow and Tipler carefully distinguish teleological reasoning from eutaxiological reasoning; the former asserts that order must have a consequent purpose; the latter asserts more modestly that order must have a planned cause. They attribute this important but nearly always overlooked distinction to Hicks (1883).^[14] This is a list of controversial non-fiction books aimed at the general reader which discuss controversial issues, or are (or were at the time of writing) controversial for other reasons. ... John David Barrow FRS (born November 29, 1952, London) is an English cosmologist, theoretical physicist, and mathematician. ... Frank J. Tipler is a professor of mathematical physics at Tulane University, New Orleans, physicist, theologian and cornucopian philosopher. ... The history of ideas is a field of research in history that deals with the expression, preservation, and change of human ideas over time. ... Intelligent design (ID) is the concept that certain features of the universe and of living things are best explained by an intelligent cause, not an undirected process such as natural selection. ... Johann Gottlieb Fichte Johann Gottlieb Fichte (May 19, 1762 - January 27, 1814) has significance in the history of Western philosophy as one of the progenitors of German idealism and as a follower of Kant. ... Georg Wilhelm Friedrich Hegel (August 27, 1770 - November 14, 1831) was a German philosopher born in Stuttgart, Württemberg, in present-day southwest Germany. ... Henri Bergson Henri-Louis Bergson (October 18, 1859 _ January 4, 1941) was a French philosopher, influential in France, but out of the main currents of his time. ... Alfred North Whitehead, OM (February 15, 1861 Ramsgate, Kent, England – December 30, 1947 Cambridge, Massachusetts, USA) was an English-born mathematician who became a philosopher. ... Omega point is a term invented by French Jesuit Pierre Teilhard de Chardin to describe the ultimate maximum level of complexity-consciousness, considered by him the aim towards which consciousness evolves. ... This article needs cleanup. ... Teleology (telos: end, purpose) is the philosophical study of design, purpose, directive principle, or finality in nature or human creations. ...

Barrow and Tipler set out in great detail the seemingly incredible coincidences that characterize our universe and that permit human beings to evolve in it. They then maintain that only the anthropic principle can make sense of this raft of coincidences. Everything from the energy states of the electron to the exact strength of the weak nuclear force seems tailored for us to exist. That our universe contains carbon-based life is contingent upon the values of several independent parameters, and were the value of any of those parameters to vary slightly, carbon-based life could not exist. While Barrow and Tipler (1986) is primarily a work of theoretical physics, it also discusses a variety of related topics in chemistry and earth science. The electron is a fundamental subatomic particle that carries an electric charge. ... The weak nuclear force or weak interaction is one of the four fundamental forces of nature. ... Chemistry (from Greek χημεία khemeia[1] meaning alchemy) is the science of matter at the atomic to molecular scale, dealing primarily with collections of atoms, such as molecules, crystals, and metals. ... Earth science (also known as geoscience, the geosciences or the Earth Sciences), is an all-embracing term for the sciences related to the planet Earth. ...

In 1983, Brandon Carter, qualifying his 1974 paper, stated that the anthropic principle, in its original form, was meant only to caution astrophysicists and cosmologists about possible errors in the interpretation of astronomical and cosmological data if they failed to take into account constraints arising from the biological nature of the observer. Carter also warned that the inverse was true for evolutionary biologists; in interpreting the evolutionary record, one must take into account cosmological and astrophysical considerations. With this in mind, Carter concluded that, given the best estimates of the age of the universe (then about 15 billion years, now 13.7 billion years), the evolutionary chain probably can allow only one or two low probability links. A. Feoli and S. Rampone^[15] argue for a higher number of low probability links, given the size of our universe and the likely number of planets. The higher number of low probability links is less consistent with the claim that the emergence of life and its subsequent evolution requires intelligent design. Intelligent design (ID) is the concept that certain features of the universe and of living things are best explained by an intelligent cause, not an undirected process such as natural selection. ...

Recent work in observational cosmology and the theory of quantum gravity has led to renewed interest in the anthropic principle. Quantum gravity attempts to unify gravity with the other forces. While there have been a number of promising developments, all such theories suffer from the problem that the fundamental physical constants are unconstrained. The observational motivation comes from more precise estimates of quantities such as the matter density of the universe. Recent estimates of this density are about 0.3, while cosmological theory generally predicts a value indistinguishable from one. // Cosmology, from the Greek: κοσμολογία (cosmologia, κόσμος (cosmos) order + λογια (logia) discourse) is the study of the Universe in its totality, and by extension, humanitys place in it. ... This article or section does not cite its references or sources. ...

There are alternatives to the anthropic principle, the most optimistic being that a Theory of everything will ultimately be discovered, uniting all forces in the universe and deriving from scratch all properties of all particles. Candidate "theories of everything" include M-Theory and various theories of quantum gravity, although all theories of this nature are currently deemed speculative. Another possibility is Lee Smolin's model of cosmological natural selection, also known as fecund universes, which proposes that universes have "offspring" which are more plentiful if they happen to have features common to our universe. Also see Gardner (2005) and his "selfish biocosm hypothesis."^[16] This article or section is in need of attention from an expert on the subject. ... M-theory is a solution proposed for the unknown theory of everything which would combine all five superstring theories and 11-dimensional supergravity together. ... This article or section does not cite its references or sources. ... Lee Smolin at Harvard Lee Smolin is a theoretical physicist who has made major contributions to the quantum theory of gravity. ... Cosmological natural selection is a hypothesis proposed by Lee Smolin intended as a scientific alternative to the anthropic principle. ... The fecund universes theory of cosmology advanced by Lee Smolin suggests that the rules of biology apply on the grandest scales. ...

Criticisms

Some forms of the anthropic principle have been criticized as an argument by lack of imagination for assuming that the only possible chemistry of life is one based on carbon compounds and liquid water (sometimes called "carbon chauvinism", see also alternative biochemistry). The range of fundamental physical constants allowing evolution of carbon-based life may also be much less restrictive than proposed.^[17] However, many of the fine-tuned details of our universe would rule out complex structures of any kind - stars, planets, galaxies etc - if violated. The argument from ignorance, also known as argumentum ad ignorantium or argument by lack of imagination, is the assertion that because something is currently inexplicable, it did not happen, or that because one cannot conceive of something, it cannot exist. ... Carbon chauvinism is the viewpoint in xenobiology that carbon is necessarily the basis of all life on other planets, as carbons chemical and thermodynamic properties render it far superior to all other elements. ... Alternative biochemistry is the biochemistry of alien life forms that differ radically from those on earth. ... In physics, fundamental physical constants are, in the strictest sense, physical constants that are independent of systems of units and hence are dimensionless numbers. ...

The WAP is being called a tautology by its supporters and a truism by its critics, for stating something not obvious to everyone yet trivially true. The weak anthropic principle implies that our ability to ponder cosmology at all is contingent on all fundamental physical parameters having numerical values falling within quite a narrow range. Critics reply that this is simply tautological reasoning, an elaborate way of saying "if things were different, they would be different". If this is granted, the WAP becomes a truism saying nothing and explaining nothing, because in order for us to be here to ponder the universe, that universe has to be structured so that we can exist. Peter Schaefer denies that labelling the WAP a truism invalidates it, on the grounds that one cannot refute a statement merely by saying that it is true. Tautology refers to a use of redundant language in speech or writing, or, put simply, saying the same thing twice. Within the study of logic, a tautology is a statement that is true by its own definition. ... A truism is a claim that is so obvious or self-evident as to be hardly worth mentioning, except as a reminder or as a rhetorical or literary device. ... Peter Schaefer is Professor of Religion and the Ronald O. Perelman Professor of Judaic Studies at Princeton University. ...

Critics of the SAP claim that it is neither testable nor falsifiable, and thus is not science. The FAP is discussed in more detail under final anthropic principle; Barrow and Tipler (1986) state that while the FAP is a valid physical statement, it is also "closely connected with moral values". Scientific method is a body of techniques for investigating phenomena and acquiring new knowledge, as well as for correcting and integrating previous knowledge. ... The final anthropic principle (FAP) is defined by physicists John D. Barrow and Frank J. Tiplers 1986 book The Anthropic Cosmological Principle as a generalization of the anthropic principle as follows: Final anthropic principle (FAP): Intelligent information-processing must come into existence in the Universe, and, once it comes...

The anthropic principle at first glance seems to discourage research into a theory of everything, however it only suggests that progress made regarding a theory of everything must allow the observer of such progress to exist. This article or section is in need of attention from an expert on the subject. ...

Hawking (2004) suggests that our universe is much less 'special' than the proponents of the anthropic principle claim it is. According to Hawking, there is a 98% chance that a Big Bang will result in a universe of the same type as ours. However, some question whether the equations Hawking employs to reach this conclusion are scientifically meaningful, and what sort of universe can be said to be of the "same type as ours". Stephen William Hawking, CH, CBE, FRS (born 8 January 1942) is a British theoretical physicist. ... According to the Big Bang, the universe emerged from an extremely dense and hot state (bottom). ...

Hawking's wave function of the universe, he and others have claimed, shows how our universe could have come into existence without any relation to anything existing prior to it, i.e., could have come out of "nothing." As of 2004, however, this work remains debatable. Moreover, as Hawking wrote in 1988, "What is it that breathes fire into the equations and makes a universe for them to describe?...Why does the universe go to all the bother of existing?" (Hawking 1988). That "there is something instead of nothing" is the fundamental problem of metaphysics. In the most restricted usage in quantum mechanics, the wavefunction associated with a particle such as an electron, is a complex-valued square integrable function ψ defined over a portion of space normalized in such a way that In Max Borns probabilistic interpretation of the wavefunction, the amplitude squared... A physical law, scientific law, or a law of nature is a scientific generalization based on empirical observations of physical behavior. ... Plato and Aristotle (right), by Raphael (Stanza della Segnatura, Rome). ...

Anthropic bias and anthropic reasoning

In 2002, Nick Bostrom asked "Is it possible to sum up the essence of observation selection effects in a simple statement?" He concluded that it might be, but that: Nick Bostrom (Boström in the original Swedish) is a philosopher at the University of Oxford, and known for his work on the anthropic principle. ...

Many 'anthropic principles' are simply confused. Some, especially those drawing inspiration from Brandon Carter's seminal papers, are sound, but... they are too weak to do any real scientific work. In particular, I argue that existing methodology does not permit any observational consequences to be derived from contemporary cosmological theories, though these theories quite plainly can be and are being tested empirically by astronomers. What is needed to bridge this methodological gap is a more adequate formulation of how observation selection effects are to be taken into account.

His Self-Sampling Assumption is "that you should think of yourself as if you were a random observer from a suitable reference class." This he expands into a model of anthropic bias and anthropic reasoning under the uncertainty introduced by not knowing your place in our universe - or even who "we" are. This may also be a way to overcome various cognitive bias limits inherent in the humans doing the observation and sharing models of our universe using mathematics, as suggested in the cognitive science of mathematics. Anthropic bias is the bias arising when your evidence is biased by observation selection effects, according to philosopher Nick Bostrom. ... The universe from a speculative theoretical physicists point of view can be described as the sum of all matter and energy that exists and the space-time in which they are located and in which all events occur or could occur. ... Cognitive bias is any of a wide range of observer effects identified in cognitive science and social psychology including very basic statistical, social attribution, and memory errors that are common to all human beings. ... The shape of the universe is a subject of investigation within cosmology. ... Euclid, Greek mathematician, 3rd century BC, known today as the father of geometry; shown here in a detail of The School of Athens by Raphael. ... The cognitive science of mathematics is the study of mathematical ideas using the techniques of cognitive science. ...

Anthropic principle in cosmic inflation

Main article: Cosmic Inflation

A critique of cosmic inflation, questioning the very premise of the theory, was offered by Don N. Page^[18] who emphasized the point that initial conditions which made it possible that a thermodynamic arrow of time in a Big Bang type of theory must necessarily include a low entropy initial state of the Universe and therefore to be extremely improbable. The critique was rebutted by P. C. W. Davies^[19] who used an inflationary version of the anthropic principle. While accepting the premise that the initial state of the visible Universe (originally a microscopic amount of space before the inflation) had to possess a very low entropy value -- due to random quantum fluctuations -- to account for the observed thermodynamic arrow of time, he deemed it not a problem of the theory but an advantage. The fact that the small fragment of space from which our Universe grew had to be extremely orderly to allow inflation resulting in a universe with an arrow of time makes it unnecessary to adopt any ad-hoc hypotheses about the initial entropy state which are necessary in other Big Bang theories. In physical cosmology, cosmic inflation is the idea that the nascent universe passed through a phase of exponential expansion that was driven by a negative-pressure vacuum energy density. ... This article or section does not cite its references or sources. ... According to the Big Bang, the universe emerged from an extremely dense and hot state (bottom). ... Ice melting - classic example of entropy increasing[1] described in 1862 by Rudolf Clausius as an increase in the disgregation of the molecules of the body of ice. ...

Anthropic principle in string theory

Main article: String theory landscape

String theory predicts a large number of possible universes, called the backgrounds or vacua. The set of these universes or vacua is often called the "multiverse" or "anthropic landscape" or "string landscape". Leonard Susskind has argued that the existence of a large number of vacua puts the anthropic reasoning on firm ground; only universes with the remarkable properties sufficient to allow observers to exist are beheld while a possibly much larger set of universes without such properties go utterly unnoted. Steven Weinberg^[20] refers to the Anthropic Principle as a "turning point" in modern science since, applied to the string landscape, it "may explain how the constants of nature that we observe can take values suitable for life without being fine-tuned by a benevolent creator." Others, most notably David Gross but also Lubos Motl, Peter Woit and Lee Smolin, argue that this is not predictive. Max Tegmark ^[21], Mario Livio and Martin Rees^[22] respond that various ingredients of well-accepted theories will never be testable, and that the test of a physical theory is not that every aspect of it should be observable and/or testable, but rather that enough is observable and testable to give confidence in the theory's correctness. The string theory landscape or anthropic landscape refers to the large number of different false vacua in string theory. ... Interaction in the subatomic world: world lines of pointlike particles in the Standard Model or a world sheet swept up by closed strings in string theory String theory is a model of fundamental physics whose building blocks are one-dimensional extended objects (strings) rather than the zero-dimensional points (particles... A multiverse (or meta-universe) is the hypothetical set of multiple possible universes (including our universe) that together comprise all of physical reality. ... The string theory landscape or anthropic landscape refers to the large number of different false vacua in string theory. ... Lenny Susskind at Stanford University Leonard Susskind is a theoretical physics professor at Stanford University in the field of string theory and quantum field theory. ... Steven Weinberg at Harvard University Steven Weinberg (born May 3, 1933) is an American physicist. ... David Gross and his wife in Santa Barbara David Jonathan Gross (born February 19, 1941 in Washington, D.C.) is an American physicist and string theorist. ... Luboš Motl in a restaurant Luboš Motl (born 1973) is a Czech theoretical physicist who works on string theory and conceptual problems of quantum gravity. ... Peter Woit at Harvard University Peter Woit is a mathematician at Columbia University. ... Lee Smolin at Harvard Lee Smolin is a theoretical physicist who has made major contributions to the quantum theory of gravity. ... Max Tegmark Max Tegmark born 1967 in Sweden to Karin Tegmark and Harold S Shapiro, is a cosmologist formerly at the University of Pennsylvania and now at the Massachusetts Institute of Technology as an Associate Professor. ... Mario Livio (born 1945) is an astrophysicist and an author of works that popularize science and mathematics. ... The Right Honourable Martin John Rees, Baron Rees of Ludlow, FRS (born 23 June 1942) is a professor of astronomy. ...

See also

• Anthropic landscape
• Big Bounce
• Cosmological natural selection
• Doomsday argument
• Fine-tuned universe
• Inverse gambler's fallacy
• metaphysical naturalism
• Perfect Cosmological Principle
• Principle of mediocrity
• Rare Earth hypothesis
• Teleology
• Weakless Universe

The anthropic landscape is the term coined by Lenny Susskind and used for a large number of different possible universes that are required for the anthropic principle. ... According to one version of the Big Bang theory of cosmology, in the beginning the universe had infinite density. ... Cosmological natural selection is a hypothesis proposed by Lee Smolin intended as a scientific alternative to the anthropic principle. ... The Doomsday argument (DA) is a probabilistic argument that claims to predict the future lifetime of the human race given only an estimate of the total number of humans born so far. ... The deepest visible-light image of the cosmos. ... The inverse gamblers fallacy is a tempting mistake in judgments of probability, comparable to the gamblers fallacy whence its name derives. ... Metaphysical naturalism is any worldview in which nature is all there is and all things supernatural (which stipulatively includes as well as spirits and souls, non-natural values, and universals as they are commonly conceived) do not exist. ... The Perfect Cosmological Principle is an extension of the Cosmological Principle stating that the Universe is not only homogeneous and isotropic in space, but also in time. ... The mediocrity principle is the notion in the philosophy of science that there is nothing special about Earth, and by implication the human race. ... In planetary astronomy and astrobiology, the Rare Earth hypothesis asserts that the emergence of complex multicellular life (metazoa) on Earth required an extremely unlikely combination of astrophysical and geological events and circumstances. ... Teleology (telos: end, purpose) is the philosophical study of design, purpose, directive principle, or finality in nature or human creations. ... The Weakless Universe is a hypothetical universe that contains no weak interactions, but is otherwise very similar to our own universe. ...

References

1. ^ Genesis of Eden Diversity Encyclopedia
2. ^ The Goldilock's Enigma,, Paul Davies
3. ^ Rabounski D. Zelmanov's Anthropic Principle and Infinite Relativity Principle. Progress in Physics, 2006, v.1, 35-37. [1]
4. ^ IAUS 63 (1974) 291
5. ^ Dicke 1957, "Principle of Equivalence and Weak Interactions," Rev. Mod. Phys. 29: 355
6. ^ Alfred R. Wallace (1904). Man's place in the universe: a study of the results of scientific research in relation to the unity or plurality of worlds, 4th ed. London: George Bell & Sons, 256-7. 
7. ^ The German Ideology, chpt. 1., Marx 1845
8. ^ John D. Barrow and Frank J. Tipler (1986). The Anthropic Cosmological Principle. Oxford Univ. Press, 16. ISBN 0-19-282147-4. 
9. ^ Barrow and Tipler 1986: 21
10. ^ Barrow and Tipler 1986: 22
11. ^ Barrow and Tipler 1986: 23
12. ^ Barrow and Tipler 1986: 677
13. ^ http://quasar.as.utexas.edu/anthropic.html
14. ^ Hicks, L. E. (1883). A Critique of Design Arguments. New York: Scribner's. 
15. ^ A. Feoli, and S. Rampone (1999). "Is the Strong Anthropic Principle too weak?". Nuovo Cim. B114: 281–289. arXiv:gr-qc/9812093.
16. ^ http://www.kurzweilai.net/meme/frame.html?main=/articles/art0647.html
17. ^ Stenger, Victor J (2000). Timeless Reality: Symmetry, Simplicity, and Multiple Universes. ISBN 1-57392-859-3. 
18. ^ D.N. Page, 1983, "Inflation does not explain time asymmetry", Nature, 304, 39
19. ^ P.C.W. Davies, 1984, "Inflation to the universe and time asymmetry", Nature, 312, 524
20. ^ http://arxiv.org/abs/hep-th/0511037
21. ^ M. Tegmark, Ann. Phys. 270, 1 (1998).
22. ^ M. Livio and M. J. Rees, Science 309, 1022 (12 August, 2003).

• Nick Bostrom, 2002. Anthropic Bias: Observation Selection Effects in Science and Philosophy. Routledge. ISBN 0-415-93858-9. 5 chapters available online.
• Brandon Carter, "Large Number Coincidences and the Anthropic Principle" in Longair, M. S., ed., IAU Symposium 63: Confrontation of Cosmological Theory with Astronomical Data. Reidel (Dordrecht, Netherlands): 291-98.
• ------, 2004, "Anthropic Principle in Cosmology." Paper presented at the conference "Cosmology: Facts and Problems," hosted by the College de France.
• Craig, William Lane, 1987, "Critical review of The Anthropic Cosmological Principle," International Philosophical Ouarterly 27: 437- 47.
• Gardner, James N., 2005, "The Physical Constants as Biosignature: An anthropic retrodiction of the Selfish Biocosm Hypothesis," International Journal of Astrobiology.
• Martin Gardner, "WAP, SAP, PAP, and FAP," The New York Review of Books 23, No. 8 (May 8, 1986): 22-25.
• Hawking, Stephen W. (1988). A Brief History of Time. New York: Bantam Books, p.174. ISBN 0-553-34614-8. 
• Kane, Gordon L., Malcolm J. Perry, and Anna N. Zytkow (2002). "The Beginning of the End of the Anthropic Principle". New Astron. 7: 45–53. arXiv:astro-ph/0001197.
• Simon Conway Morris, 2003. Life's Solution: Inevitable Humans in a Lonely Universe. Cambridge Univ. Press.
• Sober, Elliott, 2005, "The Design Argument" in Mann, W. E., ed., The Blackwell Guide to the Philosophy of Religion. Blackwell Publishers.
• Stenger, Victor J., 1999, "Anthropic design," The Skeptical Inquirer 23 (August 31 1999): 40-43
• Taylor, Stuart Ross, 1998. Destiny or Chance: Our Solar System and Its Place in the Cosmos. Cambridge Univ. Press.
• Max Tegmark, 1997, "On the dimensionality of spacetime," Classical and Quantum Gravity 14: L69-L75. A simple anthropic argument for why there are 3 spatial and 1 temporal dimensions.
• Max Tegmark, 1998, "Is `the theory of everything' merely the ultimate ensemble theory?" Annals of Physics 270: 1-51.
• Frank J. Tipler, 2003, "Intelligent Life in Cosmology," International Journal of Astrobiology 2: 141-48.
• Ward, P. D., and Brownlee, D., 2000. Rare Earth: Why Complex Life is Uncommon in the Universe. Springer Verlag.
• A Universe without Weak interactions - Roni Harnik, Graham Kribs, Gilad Perez - Phys. Rev.D74:035006,2006.

Progress in Physics is a peer-reviewed American scientific journal, registered with the United States Library of Congress. ... Alfred Russel Wallace For the Cornish painter, see Alfred Wallis. ... John David Barrow FRS (born November 29, 1952, London) is an English cosmologist, theoretical physicist, and mathematician. ... Frank J. Tipler is a professor of mathematical physics at Tulane University, New Orleans, physicist, theologian and cornucopian philosopher. ... arXiv (pronounced archive, as if the X were the Greek letter χ) is an archive for electronic preprints of scientific papers in the fields of physics, mathematics, computer science and biology which can be accessed via the internet. ... Sphere symmetry group o. ... The universe from a speculative theoretical physicists point of view can be described as the sum of all matter and energy that exists and the space-time in which they are located and in which all events occur or could occur. ... Nick Bostrom (Boström in the original Swedish) is a philosopher at the University of Oxford, and known for his work on the anthropic principle. ... Brandon Carter is a theoretical physicist, most famous for his work on the properties of black holes and for introducing the anthropic principle. ... The Coll ge de France is a higher education teaching and research establishment located in Paris, France. ... Martin Gardner (b. ... arXiv (pronounced archive, as if the X were the Greek letter χ) is an archive for electronic preprints of scientific papers in the fields of physics, mathematics, computer science and biology which can be accessed via the internet. ... Simon Conway Morris is a British paleontologist. ... The Ancient and Medieval cosmos as depicted in Peter Apians Cosmographia (Antwerp, 1539). ... Max Tegmark Max Tegmark born 1967 in Sweden to Karin Tegmark and Harold S Shapiro, is a cosmologist formerly at the University of Pennsylvania and now at the Massachusetts Institute of Technology as an Associate Professor. ... Frank J. Tipler is a professor of mathematical physics at Tulane University, New Orleans, physicist, theologian and cornucopian philosopher. ... In planetary astronomy and astrobiology, the Rare Earth hypothesis asserts that the emergence of complex multicellular life (metazoa) on Earth required an extremely unlikely combination of astrophysical and geological events and circumstances. ...

External links

• Nick Bostrom: web site devoted to the Anthropic Principle.
• Chown, Marcus, Anything Goes, New Scientist, 6 June 1998. On Max Tegmark's work.
• Stephen Hawking, Anthropic Reasoning Kavli-CERCA Conference Video Archive.
• Ikeda, Michael, and Jefferys, Bill, 2006, The Anthropic Principle Does Not Support Supernaturalism
• Tobin, Paul N., 2000, "Is the Universe Fine-Tuned for Life?" A critique of the Anthropic Principle from an atheist viewpoint.
• Steven Weinberg, 2005, Living in the multiverse
• "Anthropic Coincidence" — the anthropic controversy as a segue to Lee Smolin's theory of cosmological natural selection.
• Leonard Susskind and Lee Smolin debate the Anthropic Principle.
• debate among scientists on arxiv.org.
• Evolutionary Probability and Fine Tuning
• Critical review of "The Privileged Planet"
• Cosmologists apply anthropic reasoning different from Steven Weinberg's to universes different from ours and arrive at different(lower) "optimal" values for the cosmological constant