What makes gravity apply force to objects? Why does gravity not get pulled into the center of gravity itself, or scatter? I know that every physical body has some amount of gravity, that attracts other bodies. I also know that in order to make one physical body move, another physical body must apply force to it, so what is that physical body that gravity is made out of?
Also electric fields of magnets and atoms. What keeps the electrons from flying away from the nucleus? Is it same as gravity?
Is gravity our spacetime “sinking” into itself due to high amount of matter in one spot? Then what physical thing is the spacetime made out of to be affectable by matter?
I know its a lot of speculation and questions on my part, but i am fascinated by how physics does its thing.
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The answer isn’t completely ELI5-able, but there are two things that might help you here:
First, part of the problem is that you’re operating on this flawed premise: “in order to make one physical body move, another physical body must apply force to it.”
Forces, like the electromagnetic force or gravity, **don’t require physical contact to induce** ***accelaration***. Acceleration is a change in an object’s motion (either starting to move from relative rest, increasing or decreasing speed, or changing direction). Gravity isn’t a physical body – it’s not a *particle*, like a proton or a quark or something.
A magnet, for example, doesn’t have to touch a nail to make it move (different force, same idea). In the case of gravity, the amount of gravitational force is proportional to both mass and distance. Something massive and close exerts a lot of force, while something distant or small exerts very little.
Second… we don’t 100% know why gravity does what it does. Best guess, *very* roughly speaking, is that mass warps spacetime in a way that makes massive objects flow toward each other down the spacetime gradient. I’m sure you’ve seen the [rubber sheet analogy](https://www.youtube.com/watch?v=MTY1Kje0yLg). That’s an analogy to help people visualize the concept, rather than an actual explanation, but it’s about as close as you can get for ELI5. Getting into the moving parts much more than that requires equations and stuff.
And even then, the equations just describe the behavor – theoretical physics has been hammering away at the *why* of fundamental forces since at least the 17th century (Newton). We’ve gotten pretty good at figuring out exactly how gravity, electromagnetism, and the strong and weak nuclear forces operate – but we still don’t know exactly what makes them happen.
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