Earlier quoted context omitted.
Quantum mechanics doesn't imply at all that everything possible is actual. That is a misconception. I do agree that it makes sense, but not because of what quantum mechanics says.
Yes, it doesn't imply, but parallel universes is one of possible interpretations.
Research suggests Big Bang may have taken place inside a black hole
531–540 of 647 posts
Re: Research suggests Big Bang may have taken place inside a black hole
#532Earlier quoted context omitted.
I don't think the spacetime swap idea is particularly well explained though? Like although it's sort of mathematically true, my impression was that it's not like time suddenly becomes a dimension you're moving in once inside the event horizon, just that spacetime is acting so weird because there's now a deliberate direction where one did not exist before.
> I don't think the spacetime swap idea is particularly well explained though? What exactly do you mean by "spacetime swap idea"? If you're saying the behavior of Schwarzschild coordinates at the event horizon is not well-understood, then I disagree. There is nothing particularly weird or surprising going on, there's just a trapped surface[0]. [0]: https://en.m.wikipedia.org/wiki/Trapped_surface
Some of the problem is that Schwarzschild coordinates have surprises buried in them, and what \Delta r and \Delta t mean are not what most people tend to think.
Someone should do an ELI12 of Unruh's (ca. 2014) excellent (give or take varying the spelling of Martin Kruskal's surname) Schwarzschild BH global coordinates pedagogic review http://theory.physics.ubc.ca/530-21/bh-coords2.pdf> and add in a bit on Fermi normal coordinates as a maybe-obvious not-a-chart follow-on to the commenary just above eqn (55). But on "maybe-obvious", Unruh has the choice line: "Since in a large number of cases, the single horizon coordinates were discovered long before Schild’s coordinates, this is an exercise in alternate reality – what could have so easily happened if only the generators of those coordinate systems had recognized what they had."
Re: Research suggests Big Bang may have taken place inside a black hole
#533I have two problems / questions with this: 1. This theory requires a parent universe that can't have been formed inside a black hole. This means there must a be second "universe creation" mechanism that we can / may never know about from our child universe. For me, this doesn't really answer the true question: "How did our universe begin?" Yeah, it may the "unknown field with strange properties" but instead we get an…
> requires a parent universe Not exactly . A universe can expand, slow down, then collapse. In this case, bouncing back out. Does that repeat forever? Does it lose energy in the bounce? If so, to where and how? > The black hole in the parent universe must be much much bigger than anything we see in ours Yes and no. You're not thinking about contraction. With relativity we can fit a 100ft ladder inside a 10ft barn. Mo…
>> Yes and no. You're not thinking about contraction. With relativity >> we can fit a 100ft ladder inside a 10ft barn.
I believe the OP was talking about mass, not linear dimension. (And if he wasn't, I am.) Unless somehow mass inside a black hole is not constant? (ignoring accretion)
Re: Research suggests Big Bang may have taken place inside a black hole
#534In my view, there is one universe. We are in it. It cycles from maximum to minimum condition endlessly. This cycle is much longer than any entity lifespan and for any entity, the current state is THE state for them, and all they will know and become.
What does it expand into?
Nothing. Space itself just gets bigger and smaller over time.
No beginning, no end. It all just is.
Re: Research suggests Big Bang may have taken place inside a black hole
#535Re: Research suggests Big Bang may have taken place inside a black hole
#536Earlier quoted context omitted.
Why not? If you can't observe it, test it, and reproduce it, then it lies outside the realm of science and in the realm of belief. Until someone figures out a way to experimentally verify the big bang hypothesis (or any other explanation for the origin of the universe or what came "before"), it's entirely fair to attribute it to whatever you feel like, be it a god or anything else. There is no law of the universe tha…
If you can't observe it, test it, and reproduce it, then it lies outside of the realm of (natural) science and may lie within the realm of mathematics, philosophy, or (gasp) theology. > There is no law of the universe that guarantees that science is capable of answering all questions. There's a name for a more nuanced version of this "law" and there's a good amount of work being done arguing for and against weaker an…
Re: Research suggests Big Bang may have taken place inside a black hole
#537I have two problems / questions with this: 1. This theory requires a parent universe that can't have been formed inside a black hole. This means there must a be second "universe creation" mechanism that we can / may never know about from our child universe. For me, this doesn't really answer the true question: "How did our universe begin?" Yeah, it may the "unknown field with strange properties" but instead we get an…
Re: Research suggests Big Bang may have taken place inside a black hole
#538Earlier quoted context omitted.
But who would be as cruel to put us here without giving us those answers? Who? And where did that entity come from?
Oh that was me - I figured if I let you guys work it out for yourselves, it’d be more meaningful or whatever. As for where I came from, I gotta admit I feel curious about that too, but mostly I’m just happy to be here. Real excited to see what you do next.
Re: Research suggests Big Bang may have taken place inside a black hole
#539Earlier quoted context omitted.
I think the benefits greatly outweigh any dangers. I far prefer to read something like this than something written up by a journalist. > I acknowledge that not everyone involved in science has or wishes to acquire the skills needed to write blog-form content. They should. If your research is publicly funded you should make it as available to be public as possible. Academics should be able to communicate, and I very m…
>They should. If your research is publicly funded you should make it as available to be public as possible. Academics should be able to communicate, and I very much doubt they are unable to acquire the skills So in addition to being: -professional researchers -professional teachers -professional project managers -professional budget specialists -professional scientific writers -a failed idea away from losing it all T…
However, we live in an imperfect world. When people say "should" in these contexts, they're not describing some ideal way the world works. They're prescribing actions that are realistic based on the current system we live in.
The world sucks. It's more useful to work with the small amount of control one has, than to do nothing because the action doesn't solve a wider systemic problem.
Re: Research suggests Big Bang may have taken place inside a black hole
#540I have two problems / questions with this: 1. This theory requires a parent universe that can't have been formed inside a black hole. This means there must a be second "universe creation" mechanism that we can / may never know about from our child universe. For me, this doesn't really answer the true question: "How did our universe begin?" Yeah, it may the "unknown field with strange properties" but instead we get an…
I don't see this idea as very new. There are many models of black holes, such as the Schwarzchild solution, that have an area of "asymptotically flat spacetime" which is, from the viewpoint of our universe, part of the black hole. That something happens around the singularity that creates this new universe doesn't sound that crazy. If our universe is a child of another universe and that is a child of another universe…
To those who say "oh but if this parameter was slightly off, that thing I subjectively decided to pick wouldn't have happened!":
How would you know that this universe could exist in any other way? Wouldn't things just stabilize into certain frequencies and lengths after some time?
To me "fine tuning" isn't really a conundrum, it is just question begging and you don't need to wish it away with multiverses.