Scientific alternatives to the anthropic principle

Abstract

It is explained in detail why the Anthropic Principle (AP) cannot yield any falsifiable predictions, and therefore cannot be a part of science. Cases which have been claimed as successful predictions from the AP are shown to be not that. Either they are uncontroversial applications of selection principles in one universe (as in Dicke's argument), or the predictions made do not actually logically depend on any assumption about life or intelligence, but instead depend only on arguments from observed facts (as in the case of arguments by Hoyle and Weinberg). The Principle of Mediocrity is also examined and shown to be unreliable, as arguments for factually true conclusions can easily be modified to lead to false conclusions by reasonable changes in the specification of the ensemble in which we are assumed to be typical. We show however that it is still possible to make falsifiable predictions from theories of multiverses, if the ensemble predicted has certain properties specified here. An example of such a falsifiable multiverse theory is cosmological natural selection. It is reviewed here and it is argued that the theory remains unfalsified. But it is very vulnerable to falsification by current observations, which shows that it is a scientific theory. The consequences for recent discussions of the AP in the context of string theory are discussed.

Contribution to "Universe or Multiverse", ed. by Bernard Carr et. al., to be published by Cambridge University Press. Some references and clarifications added

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Cited by in corpus (12)

• Loop Quantum Gravity: An Inside View
• Is Our Universe Natural?
• The status of cosmological natural selection
• A perspective on the landscape problem
• The Internal and External Problems of String Theory - A Philosophical View
• Realization of Minimal Supergravity
• On making predictions in a multiverse: conundrums, dangers, and coincidences
• Towards a High Energy Theory for the Higgs Phase of Gravity
• Unification of the state with the dynamical law
• Natural intelligence and anthropic reasoning
• The Implications of the Early Formation of Life on Earth
• A Definition for Fine Tuning in Analogy to the Chaos