Why gravitons?

[gib65]

If GR already accounts for gravity, why do we need a theory of gravitons?

[D H]

Because gravity is axiomatic in GR, as is the case in Newtonian physics. It exists. Not a particularly satisfying answer, is it? Physicists are always looking for deeper meaning.

[CanadaAotS]

Yah.

 

It's like saying, "well light heats us up. Its has different frequencies. yada yada yada. Why would it need a photon?"

 

Its not so much whether we need it or not.

It's about trying to explain the universe, and how it actually works. We could probably think up some really funny explanations about why things are the way they are, but they wouldn't necessarily be true.

 

I hope at least some of what I said has any relevance lol.

[gib65]

I understand what you mean. I must be misunderstanding the relationship between gravitons and GR. I always thought that gravitons were a substitute theory for GR, but the way you two put it, it sounds like gravitons are something more fundamental than GR, something that would explain why spacetime curves in the vicinity of matter. Is this true?

 

If this is true, then I can't imagine gravitons work on physical bodies. They would have to work on warping the space between them, and then the space works on bring them closer together. Is this correct?

[swansont]

GR is also a non-quantum theory, and there is a desire to explain it at the quantum level.

 

I'm by no means an expert in GR, but that desciption appears to be how it works. It explains why there is no retardation effect for gravity, i.e. gravitationally, the force points to where the sun is now relative to us, whereas for light, the sun appears to be where it was ~8 minutes ago. (Some misinterpret this to mean that the speed of gravity is infinite, but that's not what GR predicts)

[alan2here]

there is no way we fully understand or can manipulate graverty in the same was we understand and can manipulate magnatism or static electrisity, any advances are a good thing :¬)

[[Tycho?]]

there is no way we fully understand or can manipulate graverty in the same was we understand and can manipulate magnatism or static electrisity, any advances are a good thing :¬)

 

When you post, please take a moment to read over what you wrote to make sure it makes sense.

[alan2here]

ty, what it should have read was.

 

"There is no way we fully understand or can manipulate graverty in the same way we understand and can manipulate other forces such as magnatetic fields's or electric fields.

 

any advances are a good thing :¬)"

 

also read at least the first few lines of this

http://www.esa.int/SPECIALS/GSP/SEM0L6OVGJE_0.html