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by mr_mitm 1129 days ago
> Presumably everything started at a single point in the Big Bang

That was not the case. The universe is probably infinite, thus it always has been infinite. Distances decrease as t goes to zero, but at t=0 we have a singularity. Known physics break down before that.

Besides, keeping particles entangled is actually quite difficult. Entanglement is lost as soon as they interact with their environment, in particular when being observed. This is called decoherence.

> is there any reason to believe this is even possible in theory, let alone in practice?

Yes. It has been done. https://en.wikipedia.org/wiki/Bell%27s_theorem#Experiments
1 comments
dataflow 1129 days ago
I don't follow your comment unfortunately. At t = 0 it seems the claim is we had a singularity, which I understand pretty much by definition means that all the particles (or whatever there was in the universe) were at a single point. So they all had a causal connection at that time. Right?

Also, how can you "lose" entanglement to an environment that's itself already entangled? The scientists are the environment here; if they're already entangled, surely they can't make their particles unentangled?

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mr_mitm 1129 days ago
> At t = 0 it seems the claim is we had a singularity, which I understand pretty much by definition means that all the particles (or whatever there was in the universe) were at a single point.

There is a singularity in the equations. No one knows what it actually looked like or if it even makes sense to talk about the state at t=0.

> how can you "lose" entanglement to an environment that's itself already entangled?

I don't know what you mean the environment being entangled or why you think that this is the case.

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dataflow 1129 days ago
> There is a singularity in the equations. No one knows what it actually looked like or if it even makes sense to talk about the state at t=0.

I guess I don't really care about t = 0 itself necessarily. What I'm saying is that at some point near t ~= 0 (whether that's at t = 0 or some time shortly after), everything was packed so closely that all particles would've had the time to interact with each other (and thus to become entangled). Why wouldn't this have been the case?

> I don't know what you mean the environment being entangled or why you think that this is the case.

See the above paragraph.

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