This paper argues that contemporary cosmological theories give probability one to every possible human observation being made. This creates a puzzle: if a theory predicts that every possible observation is in fact made, then how do we test it? What could possibly count as negative evidence? How can we arbitrate between rivalling cosmological theories on empirical grounds? - Only by taking observation selection effects into account, using something like the Self-Sampling Assumption!

A classic anthropic argument in cosmology.

A concise introduction to observation selection theory and its applications to cosmology, with some discussion of the challenges that arise in the case of infinite spacetimes containing an infinite number of observers.

Abstract: Recent developments in cosmology indicate that every history having a nonzero probability is realized in infinitely many distinct regions of spacetime. Thus, it appears that the universe contains infinitely many civilizations exactly like our own, as well as infinitely many civilizations that differ from our own in any way permitted by physical laws. We explore the implications of this conclusion for ethical theory and for the doomsday argument. In the infinite universe, we find that the doomsday argument applies only to effects which change the average lifetime of all civilizations, and not those which affect our civilization alone.

We argue that if string theory as an approach to the fundamental laws of physics is correct, then there is almost no room for anthropic arguments in cosmology. The quark and lepton masses and interaction strengths are determined.

Argues that the measure problem has not been solved in the particular case of anthropic arguments concerning the Cosmological Constant.

5 page postscript appended to transcript (with original figures by photocopy) of 68 page manuscript printed by stencil in 1967 under subheading "The role of fundamental microphysical parameters in cosmogony", as a foundation for what was to become known as the anthropic principle.

Applies anthropic reasoning to predictions about dark matter, and argues that in general anthropic considerations may lead us to expect many as-yet-unobserved 'coincidences'.

Applies anthropic reasoning to the Higgs vacuum expectation value.

Applies anthropic reasoning to make predictions for the dark energy equation of state, for the dark energy density, and for the long-term fate of the universe.

Anthropic principle can help us to understand many properties of our world. However, for a long time this principle seemed too metaphysical and many scientists were ashamed to use it in their research. I describe here a justification of the weak anthropic principle in the context of inflationary cosmology and suggest a possible way to justify the strong anthropic principle using the concept of the multiverse.

Improves on the Carter-Carr-Rees anthropic explanations of the proton charge and mass.

Estimates the height of the tallest running, breathing organism on a habitable planet.

Applies anthropic reasoning to make predictions for neutrino masses.