Does Space Disappear In The Big Crunch?

[Rev. Green]

If the Universe ends with a Big Crunch is "empty" space left behind or does it disappear. In fact, does space every disappear e.g. near a black hole?

[Peter Pedant]

I have real difficulty with this

I can understand easily a balloon being blown up in 3D space
but the equations involved show that in the expanding universe, this is not the case - this is cosmology and not balloon-blowing ! - and space itself is expanding or contracting

yeah OK that's why they study it at uni ....

[Peter Pedant]

My nephew is the crazy frizzy haired hand waving cosmologist and not me

[douglas9401]

You're very alike though, easy mistake to make.

My sadly limited brain says that empty space remains and waits for the next big bang to expand back into it.

See you there.

[Old_Geezer]

It is looking increasing unlikely that this universe will "end" in a "big crunch". If anything the thinning out is accelerating.

But were it to do so, physics as we know it breaks down at around the singularity, so there is a certain amount of speculation possible; but since space and matter seems to come as a set, the universe shrinking to zero is as good a definition of space = 0 as one can get.

I'm unsure of your e.g. though. Existing black holes have space, you can measure small and large ones. There's supposed to be a massive one at the centre of the Milky Way.

[ToraToraTora]

yes

[mibn2cweus]

How does something invisible . . . disappear?

[ToraToraTora]

oh dear!

[Rev. Green]

For "disappear" read "cease to exist". Space holds such a HUGE energy deficit that it isn't obvious that there is enough matter and gravitational energy to remove it.

[Old_Geezer]

Before your very eyes m2c.

If some force doesn't remove it then your Big Crunch doesn't happen and the question becomes invalid. All you are then referring to is a black hole. Like the Big Bang it'd be an all or nothing type event. Either the universe comes/goes or it does not.

[scowie]

The universe will never end in any way shape or form as there are no irreversible processes going on. The universe exists in a perpetual state of equilibrium.

Space is not a substance that can appear, disappear, warp, etc.

[Old_Geezer]

In which case, scowie, you need to come up with a better explanation of the universe and what we witness.

[scowie]

@Old_Geezer: State an observation and I will give you an explanation for it. I guarantee my explanation will be a lot more sensible than what big bang theorists have to offer.

[jim360]

Will it though? Will it?!

I mean, go on, try explaining the gravitational waves thing without, you know, General Relativity.

[scowie]

sry, I meant *real* astronomical observations, not these imaginary "detections" manufactured with abstract mathematical wizardry by theoretical physicists in order to justify the significant public funds being spent on these extravagant sideshows like CERN and LIGO ;-)

[jim360]

Ah -- can't refute the science? Then just make it sound all about the money.

P.S. My work is based on CERN physics. I can assure you it isn't ***. But then I would say that, because I get a massive amount of not all that much money for it... ?

I don't even get the arguments against, which seem entirely motivated (if memory serves) by the idea that Newton was right about everything. This seems pretty remarkable, since Newton himself was literally the first person to point out that he wasn't right about everything.