Help me understand as you do.

Actual explanations

GR is the best example

It requires no discrete lengths in space or time basically so that you can for any given curvature in space create a locally “flat” thing called a spacetime metric

To do that the world has to be continuous in time and space, so infinitely divisible

It’s really analogous with epsilon delta I think it’s callled from calculus one. Which is why infinities are also required there

I understand the necessity of it, but I fail to see how this correlates with infinity with regards to creation? While I certainly hold no credentials, and that should be apparent, how does this figure into the Lemaitre-Tolman-Bondi model?

I mean how can accelerated expansion be believed in an infinite understanding?

Perhaps I'm misunderstanding the model.

Let me look that up tbh I haven’t heard of it. Are you saying howncould they theorize that the universe expansion is accelerating indefinitely?

The expansion of the universe, and the theory of it, seem to contradict the idea of an infinite universe. I mean, how could infinity expand infinitely? That makes no sense.

Oh the ltb metric is inhomogenous which our universe isn’t

Again that's why I brought up Lemaitre and Edwin Hubble, that was their bread and butter

Yeah they are describing an inhomogenous universe which ours isn’t. But as for how infinity can expland that depends on a few things. We can pm about it if you want because my background is actually in GR and I feel like people here won’t really care

So the idea is that the universe is expanding at an accelerated rate flies in the face of the theory that the big bang is just an infinitely recurring event in the history of the universe, right?

Yes it does

An infinite universe can expand though

So is in inhomogeneous and also not isotropic?

Expansion means that the space between the points has become greater. Not that more “points” have been created. That’s one of the big confusing points in GR

Our universe is homogenous and isotropic

Oh I misread what you said my bad.

Meaning the average energy density is the same roughly everywhere, and the universe looks the same from wherever you are in it

So it would just keep expanding and never retract to the point where there is another big bang

I mean, I was taught, albeit in high school, that galaxies could be moving away from the Earth.

And that would just kind of never end?

Yes but it’s worth noting that most people don’t believe in the cyclical universe. And yes there are galaxies that move away from us due to expansion, and then there are some closer ones that move towards us regardless of expansion

The further away something is, the more the expansion has an effect. That’s why we have an “observable universe”. Beyond that point the space between us and objects there expands faster than light so we could never interact

I'm still not understanding how expansion of the universe can be at all possible when its infinite.

So what does that say about the state of the universe before the big bang?

Sure so for one we don’t know if it’s infinite. But if it were, the way it would expand is by the space between points expanding.

What could have caused the big bang if it's not possible that things retracted to that state

contracted*

We don’t really deal with that in physics. A philosophers opinion on what happened “before” the Big Bang is just as valid as a physicists

To me it doesn't sound very plausible that time existed infinitely before that

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Yeah the argument goes “how could infinite time have passed for us to be here” but we pass through infinities every day if we assume space is continuous

poster below is gay

You mean like how matter or time is infinitely divisible?

^^^^poster above is gay

Not matter but space and time

joe fuck off and fire up your charcoal grill