how the “bending space-time” visualization of gravity works/looks like in 3D space? (i.e. gravity is often visualized with a picture of a flat sheet-like plane, with a round object sitting on that plane and bending it so that objects roll towards the object).

Question

Obviously gravity isn’t acting on a 2D plane or objects would gravitate to the “bottoms” of other objects. I’m curious about whether there is a way to visualize how this model works in 3D.

In: Physics

Answer 1

As it bends 4D space while you’re a 3D being it’s quite hard to visualize. This is exactly the reason why people use the other, albeit wrong, visualisation.

Just look at a simple 4D cube, one of the basic 4D shapes, it’s quite hard to wrap one’s head around as no matter what we will always only see at best a 3D projection of that space.

Basically you could imagine a 4D “grid”, that we obviously don’t see, and mass deforming the entire grid around a body. Bodies then still move on that grid, but as it is deformed their paths are different.

But then again you’ll hardly be able to visualize a 4D grid in the first place, let alone a deformed one.