anthropic principle

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Related to Anthropic reasoning: Anthropic principle, Anthropic argument

anthropic principle

(an-throp -ik) A principle that was put forward in the 1960s by R. Dicke and maintains that the presence of life in the Universe places constraints on the ways in which the very early Universe evolved: the possible initial conditions are limited to those that give rise to an inhabited Universe, i.e. what we observe must be restricted by the conditions necessary for our presence as observers.
Collins Dictionary of Astronomy © Market House Books Ltd, 2006

anthropic principle

[an′thräp·ik ′prin·sə·pəl]
(astronomy)
The assertion that the presence of intelligent life on earth places limits on the many ways the universe could have developed and could have caused the conditions of temperature that prevail today.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
References in periodicals archive ?
To make anthropic reasoning quantitative (and hence more scientific), one must specify the a priori probabilities of the various constants of nature, and the conditional probability that intelligent life will emerge which is capable of "observing" a universe characterized by those constants.
It is worth noting that there are multiple foundational problems that bedevil anthropic reasoning (such as how to define an "observer" (5)) and even if these are overcome, there are good reasons to doubt that the probabilities needed to carry out the Bayesian inferences can ever be made accurate enough to be of value to science.
But in fact, Guth and others argue, applying anthropic reasoning to the multiverse allows calculations of some observable properties of the known universe, otherwise inexplicable.
Anthropic reasoning suggests, then, that humans should occupy a bubble with something like a typical intensity of dark energy--based on the average dark energy expected for all the bubbles where life would be possible.
Anthropic reasoning is both defeatist and dangerous, Gross proclaimed at last October's Cleveland conference: defeatist because it suggests that a more scientific explanation can never be found, and dangerous because it plays into the hands of "Intelligent Design" supporters who feel that the universe was custom-made for human beings by a benevolent God.
It gets worse: While some argue that the solar-system example proves that anthropic explanations are sometimes valid ("The reason we find ourselves on Earth is due to anthropic selection"), others cite the same example to show the folly of anthropic reasoning ("Had early astronomers been satisfied with the anthropic explanation, they might never have bothered to investigate the structure of the solar system").
If a Godelian world is a possible world, could anthropic reasoning shed any light on whether or not our world is Godelian?
Anthropic reasoning has been unpopular among some scientists because it appears to surrender predictive power.