What is gravity?

Question

I am not asking why it occurs, but what it is. Everything understood is something.

Something would entail the existence of a property, whether or not tangible.

We know photons exist, but we know they are subatomic particles.

Speaking on states and matter, is gravity matter? Does it have states? Is it solid, liquid, gas, plasma? Is it atomic, subatomic, etc.?

Natural phenomenom doesn't tell me absolutely anything about what gravity is.

So I ask again in pure simplicity ... what is gravity?

Is gravity magnetism? As such it would be a force. But I've been told that's incorrect.

Also, Eintein's "theory" doesn't answer any of these questions:

1.What causes gravity?

2.What is gravity?

3.Is gravity a force?

4.Can gravity be controlled?

Answer 1

Gravity is a fundamental force in addition to the other 3 known forces of nature that are: electromagnetism, the weak force and the strong force. Gravity acts on matter, but it is absolutely not matter.

Einstein's theory do answer the questions you listed:

1. Gravity is caused by the presence of matter who curves the spacetime continuum.
2. Gravity between two bodies is the result of the curvature of spacetime of those same bodies.
3. Einstein's theory treats gravity as something other than force, namely that it isn't a force. I will add an analogy here, to qualify gravity as a force depends on your point of reference. For instance, centrifugal force looks as if it doesn't exist to an outside observer who isn't rotating, but to an object that is doing the rotating, it's very real. To clarify more, gravity is a force relative to us who feel it's consequences, but in a more fundamental level, it is not a force but the result of the curvature of the spacetime continuum.
4. That depends on your definition of "control".

Answer 2

Andy, actually, Einstein's theories do answer at least your questions 1 through 3, and could give us a plausible reply to #4 too. In a sense #1 and #2 are the same question. I like the "net" picture for gravity: stretch a net like trapeze artists use, only make the ropes closer together. If you put something into that net, say a beach ball, and then pull the net from below, the ball will roll into the cone shape you've created. That pull on the net is mass.

So if you could control the mass, you could control gravity - but the forces to do so would be ginourmous! (You, know, it's only science fiction, (and we shouldn't pursue this more here, but it is a good image: it was either the Romulans or the Klingons who put black holes (a rip in the net by pulling too much) in front of the ships to pull them ahead at tremendous speeds. How the heck the 'held' onto a black hole is another question :))

Answer 3

Physics is not involved in telling you what things "are", but just "how" things work.

I'm sorry, but your question is totally meaningless, because you're trying to describe gravity with other things that don't have a basic definition.

Like David Hume has described: phyiscs can never give the final answer on anything, because behind every answer there's another question, while mathematics gives you final answers. So the explanation of gravity can always change, and will always entail more questions with more answers, while 1+1=2 will never ever change.