Gravity force: Isn't it just the shape of space?

[chris4642]

Isn't the force of gravity just a result of the shape of space as it is affected by masses within it? Why is it believed that it is a force associated with theoretical force particles "gravitons"? I can understand that the electric or magnetic force is a product of particles with fundamental interactions, but isn't gravity different? I always imagined gravitational force being more a geometric result of masses bending the shape of space. I am only in Physics 2, undergraduate level, but this is a question I have been thinking about for months now. Should I be thinking about this in a different paradigm?

 

[adjacent]

I think it will be very helpful to read this first: http://en.wikipedia.org/wiki/General_relativity

 

[ChrisVer]

Yes the gravity has to do with the geometry of spacetime. However QFT doesn't work like that, and so that's why you need to ask for a graviton to exist. And in the standard model you don't only have force mediator for the EM interactions (photon), you do have for the weak and strong interactions too (W's, Z and gluons).
Also there are people trying to connect the spacetime geometry to the gauge symmetries ones. For an example one could have a look at Kaluza Klein theories, trying to get a 5D spacetime and compactify the 5th dimension to a perfect circle- the result is to get gravity to the 4D and electromagnetism from the compactification (together with an extra scalar field).

 

[pervect]

Isn't the force of gravity just a result of the shape of space as it is affected by masses within it?

If you replace space with space-time, the above is the classical view of general relativity. It's a good place to start learning GR.

Why is it believed that it is a force associated with theoretical force particles "gravitons"?

That comes from a non-classical view of quantum gravity. What we need to ask here is "are the experimental predictions of this theory any different" from the former theory. I'm afraid I don't know the answer for sure.

I can understand that the electric or magnetic force is a product of particles with fundamental interactions, but isn't gravity different? I always imagined gravitational force being more a geometric result of masses bending the shape of space. I am only in Physics 2, undergraduate level, but this is a question I have been thinking about for months now. Should I be thinking about this in a different paradigm?

I would suggest sticking with your current belief as representing the prevailing picture of gravity in the textbooks and literature at the current time, but keep in mind the fundamental principle that it should be observation that ultimately decides the issue, and that no theory, however elegant, can stand unless it's confirmed by experiment.

To make a decision between the two theories, it becomes necessary to understand what the two theories (the geometric theory and the spin 2 theory) actually predict. I'm reasonably familiar with what the curved space-time theory predicts, but not so familiar as to what the spin-2 theories predict.

Two widely respected papers with somewhat different views on the topic of whether the spin-2 theory has equivalent predictions to GR:

http://arxiv.org/abs/astro-ph/0006423
http://xxx.lanl.gov/abs/gr-qc/0409089

The bottom line - I would personally recommend that you keep on as you have been, but try to keep an open mind and not get totally "locked into" one viewpoint as much as you can.

 

[sardar]

Your thinking about gravity as a result of the shape of space is not incorrect. In fact, this is the basis of Einstein's theory of general relativity, which describes gravity as the curvature of space-time caused by the presence of mass and energy. However, in order to fully understand the behavior of gravity, scientists often use the concept of gravitons, which are hypothetical particles that are thought to mediate the force of gravity.

The reason for this is that while general relativity provides a very accurate description of gravity on a large scale, it breaks down at the quantum level. This means that it cannot fully explain the behavior of gravity at a subatomic level. In order to reconcile this discrepancy, scientists have proposed the existence of gravitons, which would be the particle carriers of the gravitational force, similar to how photons are the particle carriers of the electromagnetic force.

So while your understanding of gravity as a result of the shape of space is valid, it is important to also consider the quantum nature of gravity and the potential role of gravitons in fully understanding this force. As for your level of understanding, it is great that you are thinking about these concepts deeply and asking questions. However, it is important to continue learning and exploring different perspectives and theories in order to gain a more complete understanding of complex scientific concepts. Keep up the curiosity and critical thinking!