Space and time disentangle - what does that mean?

Years ago, I saw a graphic in a magazine article about the evolution of the Universe. The graphic showed a timeline and on or about the Planck time, the caption said “space and time disentangle”. What does that mean exactly?

(Although, to be fair to the OP, the new government does have some neo-Nazi elements in it. Cite)


Are the Nazis forcibly disentangling space from time?

I have no idea what that second paragraph is doing there.

But to the cosmology question, we don’t have any theoretical basis for saying what goes on in the vicinity of the Planck scale. One might, I suppose, express this lack of theoretical basis by saying that “space and time were tangled together”, or something of the sort, in which case at some point shortly after that one would say that they “disentangled”. There’s no technical meaning to it, though.

My bad, the second paragraph was supposed to be attached to another post in another thread.

Clearly threads are displaying quantum entanglement, and perhaps tunneling through from GD.

I had not much of a clue about the answer to your question, until I realized the significance of mentioning Planck time.

Here’s my guess: Presuming that everything about Planck units is correct, then nothing can be physically smaller than one Planck length, and duration can be quicker than a Planck time. If so, then at the Big Bang, we first had nothing, and then, one Planck time later, we had Something. But that Something’s size was only 1 Planck length in any direction. Not enough time had passed for it to grow bigger in any direction.

Now, take my last sentence, and instead of the word “direction”, substitute “dimension”. At 1 Planck time, the Big Bang was not too big yet – only one Planck length in each dimension. Remember that time is a dimension too. And now that the universe is capable of length and width and height, it’s capable of duration too.

It’s a weird statement because I would’ve said space and time are entangled to this day. At least, that’s how I interpret relativity.

If space and time decoupled in some way - that is, spatial dimensions no longer had a firm relationship with time, how would anything work? Causality, motion, electromagnetic forces, gravity - everything would break up and become disorderly. I think that’s another way of saying the universe would come to an end.

Okay, I see your point. Let me try again. It all depends on exactly what we mean by “entangled”.

Are length and width currently entangled? If I have an object that is 2 feet long and 4 feet wide, then I can easily change that by just rotating it. On the other hand, the dimensions are distinct in the sense that in every reference frame, one dimension will be double another dimension.

But this is true only for 1 Planck Time and since then. Before that, the dimensions - including time - were so entangled that you couldn’t even tell them apart.

I suspect it was referring to space and time as well as the four fundamental forces “resolving” (aka “disentangling”) around the Planck time from some as yet undescribed Grand Unified state.

Those are the sort of words which go with the somewhat discredited blackhole=singularity idea.