In astrophysics and cosmology, the anthropic principle is the philosophical consideration that observations of the physical Universe must be compatible with the conscious life that observes it.

Some proponents of the anthropic principle reason that it explains why the Universe has the age and the fundamental physical constants necessary to accommodate conscious life.

The strong anthropic principle ( SAP ) as explained by Barrow and Tipler ( see variants ) states that this is all the case because the Universe is compelled, in some sense, for conscious life to eventually emerge.

Critics of the SAP argue in favor of a weak anthropic principle ( WAP ) similar to the one defined by Brandon Carter, which states that the universe's ostensible fine tuning is the result of selection bias: i. e., only in a universe capable of eventually supporting life will there be living beings capable of observing any such fine tuning, while a universe less compatible with life will go unbeheld.

The anthropic principle states that this is a necessity, because if life were impossible, no one would know it.

The term anthropic in " anthropic principle " has been argued to be a misnomer.

The anthropic principle has given rise to some confusion and controversy, partly because the phrase has been applied to several distinct ideas.

Steven Weinberg and a number of string theorists ( see string landscape ) have used this as evidence for the anthropic principle, which suggests that the cosmological constant is so small because life ( and thus physicists, to make observations ) cannot exist in a universe with a large cosmological constant, but many people find this an unsatisfying explanation.

We have only one example, rendering statistical estimates impossible, and even the example we have is subject to a strong anthropic bias.

A speculative solution is that many or all of these possibilities are realised in one or another of a huge number of universes, but that only a small number of them are habitable, and hence the fundamental constants of the universe are ultimately the result of the anthropic principle rather than a consequence of the theory of everything.

This anthropic approach is often criticised in that, because the theory is flexible enough to encompass almost any observation, it cannot make useful ( i. e., original, falsifiable, and verifiable ) predictions.

Explanations often invoked to resolve fine-tuning problems include natural mechanisms by which the values of the parameters may be constrained to their observed values, and the anthropic principle.

* A simple anthropic argument for why there are 3 spatial and 1 temporal dimensions.

One possible explanation for the small but non-zero value was noted by Steven Weinberg in 1987 following the anthropic principle.

The reason for the noocytes ' inability to remain in this reality is somewhat related to the strong anthropic principle.

* The anthropic fine tuning of the universe: He quotes with approval Freeman Dyson, who said " the more I examine the universe and the details of its architecture, the more evidence I find that the universe in some sense must have known we were coming " and suggests there is a wide consensus amongst physicists that either there are a very large number of other universes in the Multiverse or that " there is just one universe which is the way it is in its anthropic fruitfulness because it is the expression of the purposive design of a Creator, who has endowed it with the finely tuned potentialty for life.

In The Anthropic Cosmological Principle ( 1986, see anthropic principle for details ) John D. Barrow and Frank J. Tipler identify Whiggishness ( Whiggery ) with a teleological principle, of ' convergence ' in history to liberal democracy.

Lucas ( 1961 ) began a lengthy and heated debate over the implications of Gödel's incompleteness theorems for the anthropic mechanism thesis, by arguing that:

The debate over anthropic mechanism seems here to stay, at least for the time being.

The second option, common amongst philosophers who adopt anthropic mechanism, is to argue that the arguments given for incompatibility are specious: whatever it is we mean by " consciousness " and " free will ," they urge, it is fully compatible with a mechanistic understanding of the human mind and will.

Nick Bostrom ( born Niklas Boström on 10 March 1973 ) is a Swedish philosopher at the University of Oxford known for his work on existential risk and the anthropic principle.

In this way, top-down cosmology provides an anthropic explanation for why we find ourselves in a universe that allows matter and life, without invoking the existence of the Multiverse.

Climax vegetation is the vegetation which establishes itself on a given site for given climatic conditions in the absence of anthropic action after a long time ( it is the asymptotic or quasi-equilibrium state of the local ecosystem ).

Known as the anthropic coincidence or fine-tuned universe, it simply states that the large numbers in LNH are a necessary coincidence for intelligent beings since they parametrize fusion of hydrogen in stars and hence carbon-based life would not arise otherwise.

# Some people have philosophical reasons for doubting the possibility of human extinction, for instance the final anthropic principle, plenitude principle or intrinsic finality.

Brandon Carter, FRS ( born 1942 ) is an Australian theoretical physicist, best known for his work on the properties of black holes and for being the first to name and employ the anthropic principle in its contemporary form.

Bonny Susan Hicks ( 5 January 1968 – 19 December 1997 ) was a Singapore Eurasian model who gained her greatest notoriety for her contributions to Singaporean post-colonial literature and the anthropic philosophy conveyed in her works.

The anthropic principle is a controversial argument of why the fine-structure constant has the value it does: stable matter, and therefore life and intelligent beings, could not exist if its value were much different.

The thesis in anthropic mechanism is not that everything can be completely explained in mechanical terms ( although some anthropic mechanists may also believe that ), but rather that everything about human beings can be completely explained in mechanical terms, as surely as can everything about clockwork or gasoline engines.

This provided a simple scientific interpretation of the cosmological anthropic principle: Our world may consist of different parts, but we can live only in those parts of the multiverse which can support life as we know it.

The hypothetical concept of the anthropic landscape in string theory follows from a large number of possibilities in which the integers that characterize the fluxes can be chosen without violating rules of string theory.

The weak anthropic principle could then be applied to conclude that we ( as conscious beings ) would only exist in one of those few universes that happened to be finely tuned, permitting the existence of life with developed consciousness.

* 1961 — Robert Dicke argues that carbon-based life can only arise when the gravitational force is small, because this is when burning stars exist ; first use of the weak anthropic principle

This was the first modern application of what is now called the weak anthropic principle.

You can only be born into one, so the indifference principle within this ( humans-across-universes ) reference class would mean that the chance of being born into a particular universe is proportional to its weight in humans, N. ( Echoing the weak anthropic principle.

He believes the chances of life arising on a planet like the Earth are many orders of magnitude less probable than most people would think, but the anthropic principle effectively counters skepticism with regard to improbability.

A somewhat similar belief today is anthropic principle, but it only states that laws of physics are useful.

Today, as in the past, the main points of debate between anthropic mechanists and anti-mechanists are mainly occupied with two topics: the mind — and consciousness, in particular — and free will.

Critics also suggest that the fine-tuned Universe assertion and the anthropic principle are essentially tautologies.

The Multiverse hypothesis assumes the existence of many universes with different physical constants, some of which are hospitable to intelligent life ( see multiverse: anthropic principle ).

But this hypothesis is not central to their book, a very thorough study of the anthropic principle, and of how the laws of physics are peculiarly suited to enable the emergence of complexity in nature.

They believe that quantum wave-functions do not collapse like the Copenhagen interpretation holds, nor that each collapse actually buds off separate universes ( like the quantum multiverse hypothesis holds ) but rather that the universe is a participatory universe: the entire universe exists as a single massive quantum superposition, and that at the end of time ( in the open universe of the Xeelee Sequence, time and space are unbounded, or more precisely, bounded only at the Cauchy boundaries of " Time-like infinity " and " Space-like infinity "), when intelligent life has collected all information ( compare the Final anthropic principle and the Omega Point ), and transformed into an " Ultimate Observer ", who will make the " Final observation ", the observation which collapses all the possible entangled wave-functions generated since the beginning of the universe.

Geographers and soil scientists are interested in the utility of anthropic soils caused by burning in the past.