(September 17, 2021 at 9:28 am)Mister Agenda Wrote:(September 16, 2021 at 2:44 pm)Klorophyll Wrote: The no boundary proposal entails that the universe began to exist,
https://en.wikipedia.org/wiki/Hartle%E2%...king_state
QUOTE :However, Hawking does state "...the universe has not existed forever. Rather, the universe, and time itself, had a beginning in the Big Bang, about 15 billion years ago."
If the universe has not existed forever, it began to exist.
Thanks for sharing Hawking's opinion, but his hypothesis, like the other hypotheses for the origin of the universe, can't be tested yet. If Hawking is right, the universe began to exist from nothing. If Hawking is wrong, a universe that has always existed in some form is still on the table. And there's no way to know if Hawking at this time is right or wrong on this matter.
Arguing from Hawking as an authority on cosmology is at least citing a relevant expert, but the problem is cosmology isn't settled and plenty of eminent cosmologists disagree with him.
The no-boundary proposal is just that - a proposal. It also seems the math may not work.
The idea is that there was "something" before the big-bang, but it wasn't a singularity, and time and space as we know it emerged smoothly as a phase transition.
There is also no causality "as we know it" in this pre-universe state.