npub1z2qdmfzhs2uwg8kmsh37xavt2hq48gch63e787ggd3s6mt8waxgsxu3yuf (npub1z2q…3yuf) npub1dkc8czfyk0drm4ln98ux3tnfkp4tkcfmtms32redy9ta2wtq0cmsuz8yll (npub1dkc…8yll) I think the certainty must lie in their definition of infinity, and it's a definition that seems to me to be shared by a lot of professional physicists:
"infinity is the size of all possibilities". Are there alternate realities? An infinite number you say? Obviously they must contain every conceivable variation of me, and of Earth, etc.
That's not true, of course; every reality could be the same, for instance. "But then you don't need infinity, that's only one." There may be a kind of conceptual size optimization there that brains do automatically. Perhaps.
But physicists talking about infinite realities, and/or infinite spatial universes, seem to make this conceptual error quite often.
They may make caveats about the obvious exceptions, like the above one where all are identical, but the *real* "infinite universes" tends to be assumed to be "all possible universes".
P.S. I have tried to wrap my mind around what new possibilties are possible (or required) if the number of (ergodic) realities / universes is ℵ 1 rather than ℵ 0 . It can definitely be a confusing topic.