Eli5: What exactly is space-time?

361 viewsOtherPlanetary Science

So I was reading up about gravity and how objects with a bigger mass actually “bend” the fabric of space which is often called space-time. But what is it exactly?

Can we see space-time? Does it actually exist or is it just a concept/hypothetical?

Also, an article mentioned that that we need to be in the 5th dimension to actually see space-time. So, does that prove higher dimensions do in fact exist and are having an impact on our 3D world?

In: Planetary Science

5 Answers

Anonymous 0 Comments

Spacetime is real in the sense that we can measure it and model it and see how changes in spacetime have real effects, but it’s not actually a physical thing that you can see or touch. Rather, it’s a mathematical construct for us to understand how things exist in and move through 3 dimensions in space and 1 dimension of time, and how events can influence each other in space and time.

As to that article you read, I’m not sure where that came from, but it sounds like a pop-sci article, and you should be very careful with those because they are usually wrong. In short, no, you would not need to be a a 5th dimension to see spacetime, since spacetime isn’t a thing you can see anyway, and it does not in any way prove or even hint at the existence of higher spatial dimensions. There’s zero evidence of the existence of more than the 3 dimensions of space that we already know.

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