What are the accepted theories for the source of gravity?

[mijalasthapit]

We can use Newton's Law of Universal Gravitation to calculate how strong the gravitational pull is between the Earth and the object you dropped, which would let us calculate its acceleration as it falls, how long it will take to hit the ground, how fast it would be going at impact, how much energy it will take to pick it up again, etc.

 

[mijalasthapit]

A theory starts as one or more hypotheses, untested ideas about why something happens. For example, I might propose a hypothesis that the object that you released fell because it was pulled by the Earth's magnetic field. Once we started testing, it would not take long to find out that my hypothesis was not supported by the evidence. Non-magnetic objects fall at the same rate as magnetic objects. Because it was not supported by the evidence, my hypothesis does not gain the status of being a theory. To become a scientific theory, an idea must be thoroughly tested, and must be an accurate and predictive description of the natural world.

 

[sophiecentaur]

Wait... my post says greatest at the surface. I think I meant at the core.
Which one did you mean?

Also, we might want to avoid talking GR in this thread, it's getting really messy.

Haha. I assumed you meant Centre. But mine was an actual question. I am not sure about any of this except to say "expect to be confused and misled". It will not be intuitive.
Any ideas we offer must be consistant with classical experience.

 

[ZionsRodeVos]

All the information is very useful too me as I want to understand all the theories related to gravity and how those theories relate to one another.

If I have understood correctly string theory is the theory that has a graviton in it and thus far there is little or no evidence to support string theory. Does that mean that even though it is called string theory it is really only a hypothesis at this point?

If graviton's were found would that change people's understanding of general relativity and/or Newton's theory of gravity?

 

[DrewD]

If I have understood correctly string theory is the theory that has a graviton in it and thus far there is little or no evidence to support string theory. Does that mean that even though it is called string theory it is really only a hypothesis at this point?

I'm pretty sure that Feynman and others worked out a gravitational field theory in the 60's that predicted a graviton. The theory did not work under certain circumstances (maybe all?) when combined with GR and was scrapped. I think gravitons show up in a number of theories, but none that are fully consistent with GR or that have been experimentally confirmed.

If graviton's were found would that change people's understanding of general relativity and/or Newton's theory of gravity?

I don't think that confirmation of a graviton alone would change theories much, but there might be certain values related to it that could rule out certain theories. For example, a graviton with mass would cause trouble in a number of theories. I don't think anyone is seriously looking for them though. They are (would be) very difficult to observe.



mijalasthapit, it would be better if you posted everything in one post.

 

[darkxponent]

I'll tell you why things have mass.
They just do.

Awesome lines!