If the expansion of the universe continues to speed up forever

[Yora]

Current data shows that the universe is expanding and that the rate of expansion is increasing.

As a consequence, even though the observable universe is getting bigger in volume, stuff is spreading out faster, so there is less and less stuff that we can see.

Currently, the gravitational pull of stars on the scale of galaxies and galaxy groups is strong enough to overcome the expansion of space and keep the galaxies together.

But could the rate of expansion become so fast that no two particles in the universe could interact with each other at the speed of light? Would that be a contender for the definition of "the end of the universe"?

[Lord Torath]

That is the currently-understood end of the universe, yes. Things just spread out and keep on spreading until there are billions of light years between any to sub-atomic particles forever.

[Vahnavoi]

Accelerating expansion leading to end of the universe is called the Big Rip hypothesis (https://en.m.wikipedia.org/wiki/Big_Rip). It's been around for a while. Current observations suggest it may not happen.

[Bohandas]

The question that's always intrigued me is how this scenario would interact with color confinement (https://en.wikipedia.org/wiki/Color_confinement). If color confinement is absolute, would a big rip result in a new big bang?

[Solauren]

There is also the question of what is the universe part of, if anything.

If it's part of multiverse, with each universe being like it's own cell in a larger body, should a big rip occur, the matter within will not be destroyed, but either end up in a region between universes, and possibly sucked up into other universes.

There is also the possibility that once our universe gets to a certain point, it will hit other universes, and the impact of that will cause our universe (or at least part of it) to rebound back.

Essentially turning each universe into it's own game of pool, with each galaxy being one of billions of balls bouncing around, colliding with each other, as they bounce off the edge of the unverse, and recolide towards the middle, or eventually get sucked into the side pockets (black holes)

[halfeye]

There is also the question of what is the universe part of, if anything.

If it's part of multiverse, with each universe being like it's own cell in a larger body, should a big rip occur, the matter within will not be destroyed, but either end up in a region between universes, and possibly sucked up into other universes.

I think anyone who thinks there's a case for a multiverse just doesn't understand how big this universe is, this current universe is totally, ridiculously, huge.

[Solauren]

I think anyone who thinks there's a case for a multiverse just doesn't understand how big this universe is, this current universe is totally, ridiculously, huge.

You realize, of course, how that could have been applied to several other 'theories' and views that were misproven?

Like....
"Anyone who thinks there a case for the world being flat just doesn't understand how big the Earth is. It's totally, ridiculously, huge"

"Anyone who thinks the Earth revolves around the sun just doesn't understand how the universe works"

etc.

[halfeye]

You realize, of course, how that could have been applied to several other 'theories' and views that were misproven?

Like....
"Anyone who thinks there a case for the world being flat just doesn't understand how big the Earth is. It's totally, ridiculously, huge"

"Anyone who thinks the Earth revolves around the sun just doesn't understand how the universe works"

etc.

Sure, but how big do you think the universe is? Are you really arguing that the earth is flat?

[Lord Torath]

Sure, but how big do you think the universe is? Are you really arguing that the earth is flat?No. He's just saying the argument that the universe is really, really, really huge is not proof that there can't be something larger, or something beyond it.

[halfeye]

No. He's just saying the argument that the universe is really, really, really huge is not proof that there can't be something larger, or something beyond it.

It's not proof, but it's very, very suggestive.

Just look at this lot:

https://www.syfy.com/syfywire/a-moment-of-the-universe

That's not just a bit further than the shop on the street corner.

[asda fasda]

It's not proof, but it's very, very suggestive.

Just look at this lot:

https://www.syfy.com/syfywire/a-moment-of-the-universe

That's not just a bit further than the shop on the street corner.

The image is beautiful, although as my wallpaper I have ultradeep field photo from Hubble so yeah the universe is so vast huge, but I don't see why this would mean that there is a little possibility for multiverse, if anything it proves that our reality doesn't adhere to any human concept of size, so there is no reason why there couldn't be anything even bigger.

Even if you argue that universe is infinite then this still doesn't preclude multiverse as we know that there are bigger and smaller infinites as well as there can be infinite bound between something finite (like there is infinite numbers between 0 and 1)

[halfeye]

The image is beautiful, although as my wallpaper I have ultradeep field photo from Hubble so yeah the universe is so vast huge, but I don't see why this would mean that there is a little possibility for multiverse, if anything it proves that our reality doesn't adhere to any human concept of size, so there is no reason why there couldn't be anything even bigger.

Even if you argue that universe is infinite then this still doesn't preclude multiverse as we know that there are bigger and smaller infinites as well as there can be infinite bound between something finite (like there is infinite numbers between 0 and 1)

The way it seems to me is that the hugeness of the universe precludes multiverses because there's no need for them, we can explore this universe for as long as we like, and we'll never get to the end of it.

The universe as it stands is undetermined whether it's massive enough that it constitutes a black hole or not, bring in another of a similar mass and a black hole would be almost inevitable, three or four and it's totally certain.

[Fyraltari]

The way it seems to me is that the hugeness of the universe precludes multiverses because there's no need for them, we can explore this universe for as long as we like, and we'll never get to the end of it.

Reality doesn't care about what we need.

[halfeye]

Reality doesn't care about what we need.

It at least seems to care about the elegance and economy of rulesets. Multiverses are inelegant and the rulesets seem likely to be a mess.

[Lord Torath]

How closely have you looked at the laws of physics for this universe? Bits are elegant, but there are also bits that are a mess.

[Bohandas]

It at least seems to care about the elegance and economy of rulesets. Multiverses are inelegant and the rulesets seem likely to be a mess.

The universe runs on poor accounting. Waveform collapse is the universe going "oh **** we need to know where that electron is"

[asda fasda]

I'm not sure what is inelegant in multiverse.

Additionally multiverse helps to explain elegantly some constants in physics which doesn't seem to have any reason to have the value that are measured.

[Mastikator]

I think anyone who thinks there's a case for a multiverse just doesn't understand how big this universe is, this current universe is totally, ridiculously, huge.

There are many cases for multiverses, different kinds of multiverses.

The many worlds interpretation of quantum field theory states that when a wave function collapses it splits the universe into multiple universes, one for each possible result
Then there's eternal inflation, which is just inflation but without assuming it would have to end everywhere at the same time
There's also the string theory one, but I dislike how popular string theory is, it's just not justified by the evidence
There's also the "before big bang" one, where we try to answer "why is the universe so well suited for life" (it's not), and you merely replace a fine-turning assumption with the anthropic principle
Also arguably any part of the universe that is behind some kind of event horizon is arguably in a separate universe since it is causally disconnected