shira
Diamond Member
Cosmology isn't my area, but I think that the probabilistic nature of particles would lead to vast differences in the outcomes of - say - two universes with identical initial conditions.
About two years ago, I read an article (I can't remember where) about how even the tiniest changes in the parameters that defined the degree and nature of cosmic inflation (CI) in the primordial universe would have led to a vastly different universe, such as one in which neither starts nor planets (nor, obviously, any life forms) could form. So it would seems that we humans are extraordinarily lucky to have been blessed with just the precise set of CI values that allowed a universe filled with stars and planets to arise. But that's the old "survivor bias" again: we wouldn't be here to marvel at our incredibly good luck if our universe had not had those rare CI values. Even if only one in 10^100 universes satisfies the necessary conditions, given 10^100,000,000,000 universes, there are a ton of universes containing intelligent beings marveling at their good fortune.
It also seems likely that the particular laws of physics that apply to a given universe might themselves be a consequence of the CI values. Perhaps if we could evaluate the laws of physics in a universe that was wildly different from our own we'd see laws that were wildly different. Unfortunately, such a universe wouldn't support life, so there would be no one to perform the needed measurements. At any rate, for any universe where there's someone around to do the evaluating (in other words, one of those very rare universes with stars and planets), the laws of physics are probably very, very similar.
