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
We live in 3D space, which means you need 3 numbers to describe where something is in space, like “1m forward, 1m left and 1m up” uniquely describes a position in space (relative to some starting point). In spacetime you describe events using 3 numbers for the location and one for the time an event happens, like “1m forward, 1m left, 1m up and 6 seconds in the future”. Whether spacetime is real or not is more of a philosophical question, but most people would say space and time are real, and spacetime just puts them together, so it should probably also be real. The 5th dimension thing means that, since spacetime is 4 dimensional (3 space dimensions + time), in order to really see something moving through spacetime, you’d have to look at it from “outside 4d space” (i.e. at least 5d), the same way you can only see an entire sheet of paper (2d) if you’re looking at it from above (3d).
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