[Strilanc]

If the universe we find ourselves in is a result of post-selecting for mathematical models where life can exist (i.e. by the anthropic principle), why is the universe so large and so rich in neg-entropy? Shouldn't minimally-viable-habitat universes be vastly, vastly more numerous (and don't forget about Boltzmann brains!)? Shouldn't we expect to be in one of those, instead of here, and be forced to penalize the hypothesis by a corresponding amount? [1]

> So, as cosmologists, we have an issue to address — why was the entropy of our early universe so small? If high-entropy states are “natural,” why don’t we live in one? You might think to appeal to the dreaded anthropic principle, and argue that life couldn’t exist in a state with really high entropy. But that turns out not to be good enough; the entropy of our universe is much much lower than it needs to be to support the existence of life. So we are faced with the “arrow of time problem.”

1: http://www.preposterousuniverse.com/blog/2004/10/27/the-arro...

[jameshart]

The problem with these kinds of arguments-from-probability is that they are valid arguments even in highly improbable universes. So yes, maybe on average, most sentient life forms that ponder these questions are living inside tiny simulated universes created as undergraduate term projects for passing credit. But we happen to be in a really big universe. Maybe ours is a grad student lab project. Or an exhibit in a museum. Or maybe we hit the jackpot and ours is real. Point of such arguments is you can't really tell from a sample size of one.