1
vote
1answer
171 views

Fine tuning: why is multiverse with anthropic principle considered a better explanation than anthropic principle alone?

I got the impression from several public lectures that, when it comes to the fine tuning problem, physicists tend to give multiverse together with anthropic principle as a plausible solution, but ...
6
votes
2answers
1k views

Why aren't we Boltzmann brains in an infinite universe?

Either space is finite or it is infinite. a) - If space is infinite in extent, either it is thermal over an infinite volume, or it is in the vacuum state for most of it. If it is thermal, infinity ...
4
votes
1answer
220 views

Is the only diffeomorphism invariant anthropic principle the final anthropic principle?

Quantum gravity is a gauge theory with the gauge symmetry spacetime diffeomorphisms. Presumably the quantum state of our universe is invariant under spacetime diffeomorphisms, including timelike ...
2
votes
1answer
306 views

Does a complete theory of quantum gravity require anthropic post-selection?

Does a complete theory of quantum gravity require anthropic post-selection? Certainly the black hole complimentarity and causal patch conjectures highlights the essential role of observers, at least ...
4
votes
1answer
156 views

Fine Tuned Universe

Is the fine tuning that cosmologists talk about (that our Universe is fine tuned for intelligent life) is the same as the fine tuning of the squared mass parameter of the Higgs in the Standard Model? ...
6
votes
6answers
882 views

Are many-worlds and the multiverse really the same thing?

Are many-worlds and the multiverse really the same thing? Not too long ago, Susskind and Bousso uploaded the article "The Multiverse Interpretation of Quantum Mechanics" with the thesis that the ...
5
votes
2answers
398 views

Undergraduate-friendly reading material on the multiverse?

I'll be teaching a seminar for first-year undergraduates next year. The idea of my university's first-year seminar program is to expose students to exciting ideas and important texts in a somewhat ...
8
votes
6answers
571 views

Can (or How) Anthropic Principle be Made into a Scientific Theory?

Anthropic Principle says physical Universe must be compatible with the conscious life that observes it. I thought it is just philosophy mumbo-jumbo and it's not physics. But I could be ...