Editing Anthropic principle (section)

=== String theory ===
{{Main|String theory landscape}}

[[String theory]] predicts a large number of possible universes, called the "backgrounds" or "vacua". The set of these vacua is often called the "[[multiverse]]" or "[[String theory landscape|anthropic landscape]]" or "string landscape". [[Leonard Susskind]] has argued that the existence of a large number of vacua puts anthropic reasoning on firm ground: only universes whose properties are such as to allow observers to exist are observed, while a possibly much larger set of universes lacking such properties go unnoticed.<ref name="arXiv:hep-th/0302219"/>

[[Steven Weinberg]]<ref>{{Cite conference |author=Weinberg, S. |author-link=Steven Weinberg |year=2007 |title=Living in the multiverse |book-title=Universe or multiverse? |editor=B. Carr |publisher=Cambridge University Press |isbn=978-0-521-84841-1 |arxiv=hep-th/0511037 |bibcode=2005hep.th...11037W }}</ref> believes the anthropic principle may be appropriated by [[cosmologist]]s committed to [[nontheism]], and refers to that principle as a "turning point" in modern science because applying it to the string landscape "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 [[Luboš Motl]], [[Peter Woit]], and [[Lee Smolin]]—argue that this is not predictive. [[Max Tegmark]],<ref>Tegmark (1998) op. cit.</ref> [[Mario Livio]], and [[Martin Rees]]<ref>{{Cite journal |author=Livio, M. |author2=Rees, M. J. |name-list-style=amp |title=Anthropic reasoning |journal=Science |volume=309 |pages=1022–1023 |year=2003 |doi=10.1126/science.1111446 |pmid=16099967 |issue=5737 |bibcode=2005Sci...309.1022L |s2cid=40089857 }}</ref> argue that only some aspects of a physical theory need be observable and/or testable for the theory to be accepted, and that many well-accepted theories are far from completely testable at present.

[[Jürgen Schmidhuber]] (2000–2002) points out that [[Ray Solomonoff]]'s [[Solomonoff's theory of inductive inference|theory of universal inductive inference]] and its extensions already provide a framework for maximizing our confidence in any theory, given a limited sequence of physical observations, and some [[prior distribution]] on the set of possible explanations of the universe.

[[Zhi-Wei Wang]] and [[Samuel L. Braunstein]] proved that life's existence in the universe depends on various fundamental constants. It suggests that without a complete understanding of these constants, one might incorrectly perceive the universe as being intelligently designed for life. This perspective challenges the view that our universe is unique in its ability to support life.<ref>{{cite journal |last1=Wang |first1=Zhi-Wei |last2=Braunstein |first2=Samuel L. |year=2023 |title=Sciama's argument on life in a random universe and distinguishing apples from oranges |journal=Nature Astronomy |volume=7 |issue=2023 |pages=755–756 |doi=10.1038/s41550-023-02014-9 |arxiv=2109.10241 |bibcode=2023NatAs...7..755W }}</ref>

{{Anchor|Spacetime}}