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glueball8
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Can gravitons bend space-time? How can it be shown experimentally? Ideas?
dmatador said:What does your intuition tell you concerning this question?
Space-time is bent by mass, and gravity (and thus, i suppose, the hypothetical gravitons) exists through this sloping of space-time. Gravitons are said to have no mass (if they exist), so intuitively, how do you suppose they could affect space-time? Secondly, no one is sure if gravitons exist, so maybe the question should initially be "how can we find out if gravitons exist?" and then ask what do they do and how do they behave.
dmatador said:What does your intuition tell you concerning this question?
Space-time is bent by mass, and gravity (and thus, i suppose, the hypothetical gravitons) exists through this sloping of space-time. Gravitons are said to have no mass (if they exist), so intuitively, how do you suppose they could affect space-time? Secondly, no one is sure if gravitons exist, so maybe the question should initially be "how can we find out if gravitons exist?" and then ask what do they do and how do they behave.
cragar said:A graviton must posses a self-energy . And doesn't a magnetic field create a gravitational field .
In what sense? Assuming that gravitons exist, a gravitational field would be an area in which the effects of a graviton would be exerted, therefore, to 'create' another gravitational field, one of two things might happen:cragar said:so then I am guessing that a gravitational field cannot create another gravitational field ?
n rereading my post #7, I don't like it much now...because as in other posts here we are mixing two theories...GR says gravity is a warping of space, a geometrical description ...gravitons result from quantum mechanical (particle) considerations rather than geometrical ones...so describing either particle interactions or geometric explanations depends on which theory you are using...GR and QM don't mesh/mix all that well so far...that would be the result of grand unification combining all forces.
However, there is a perfect analogy between space warping and exchanging virtual particles. These are two mathematical ways to describe the same thing. So GR and QFT are not as far away of each other as it seems.
I have never seen a theory which describes exchange of virtual particles bending spacetime via a back-reaction. So I don't see this analogy. Where shall it come from?However, there is a perfect analogy between space warping and exchanging virtual particles. These are two mathematical ways to describe the same thing. So GR and QFT are not as far away of each other as it seems.
Both theories describe interacting bodies.I don't see this analogy. Where shall it come from?
I don't say that QFT-like approach to GR will lead us to Truth. I just say, that both GR and QFT describe... something and that "something" is similar in these theories both physically and mathematically. We can call it spacetime warping from GR standpoint or virtual particles from other side, but it is the same. What I say: GR and QFT are not that incompatible as most people think. That is, we can "mix" GR and QFT to some extent, say introduce gravitons.What I am wondering is that so many people know about the similarities between QFT and GR and at the same time try to use concepts which are known to fail even in many areas of QFT
I agree with everything except for the "virtual particles from other side". They are a very limited concept and I don't think that they will help to understand QG.haael said:I don't say that QFT-like approach to GR will lead us to Truth. I just say, that both GR and QFT describe... something and that "something" is similar in these theories both physically and mathematically. We can call it spacetime warping from GR standpoint or virtual particles from other side, but it is the same. What I say: GR and QFT are not that incompatible as most people think. That is, we can "mix" GR and QFT to some extent, say introduce gravitons.
So GR and QFT are not quite that different. The last thing is to find interpretations of gauge fields in GR and spacetime bending in QFT. Kaluza-Klein-like theories are most promising IMO.
What do you mean by this , Could gravitons be similar to photons in their behavior ,Naty1 said:Gravity IS a self interacting phenomena..
haael said:In GR we have:
[tex]D_{\mu} \phi_{\nu} = d_{\mu} \phi_{\nu} - \Gamma^{\alpha}_{\mu \nu} \phi_{\alpha}[/tex]
while in QFT:
[tex]D_{\mu} \phi(q) = d_{\mu} \phi(q) - i A_{\mu} q \phi(q)[/tex]
Gravitons are theoretical particles that are hypothesized to carry the force of gravity in the framework of quantum mechanics. They are predicted by the theory of general relativity, but have not yet been directly observed.
Gravitons are thought to interact with particles and objects with mass, causing them to curve the fabric of space-time. This curvature is what we perceive as the force of gravity.
Currently, we do not have the technology to directly detect gravitons. However, scientists are working on experiments, such as the Laser Interferometer Gravitational-Wave Observatory (LIGO), to indirectly detect their effects.
Some theories, such as string theory, suggest that gravitons may exist in higher dimensions. However, this is still a topic of ongoing research and has not been confirmed.
The existence of gravitons would provide a better understanding of how gravity works at the quantum level. It would also help reconcile the theories of general relativity and quantum mechanics, which currently have different explanations for gravity.