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I find gravity interesting, because everything that exists interacts with everything via the gravitational field. This is not the case with any other sort of in
by Xcelerate 7y ago
I find gravity interesting, because everything that exists interacts with everything via the gravitational field. This is not the case with any other sort of interaction; gravity is truly different. See this diagram showing the ways that different particles can interact in the Standard Model: https://upload.wikimedia.org/wikipedia/commons/thumb/4/4c/Elementary_particle_interactions.svg/400px-Elementary_particle_interactions.svg.png https://upload.wikimedia.org/wikipedia/commons/thumb/4/4c/El...
Photons, for instance, cannot interact directly with each other via the electromagnetic field. Gluons do self-interact via the strong interaction. But both photons and gluons interact with all types of particles via gravity (although sometimes this interaction is so small that we would never be able to measure it).
- danbruc 7y agoPhotons do interact electromagnetically [1], just not in the same direct way as gluons. [1] https://en.wikipedia.org/wiki/Two-photon_physics https://en.wikipedia.org/wiki/Two-photon_physics
- Xcelerate 7y agoYeah, I was more so speaking of direct coupling but didn’t want to get too technical. That interaction is due to virtual fermion-antifermion pairs.
- 100ideas 7y agoIs it ok to mentally replace the word/concept “gravitational field” with “energy density field”? If so it resolves the mysterious central relationship this field has for all the others.
- liberte82 7y agoHow does one particle know that is here know that there's another one over there?
- 100ideas 7y agoHow does spacetime know to curve?