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I’m sure physicists have already thought about this but… Has anyone considered modeling the effect currently explained via dark matter as a new kind of force o

by api 4y ago

I’m sure physicists have already thought about this but… Has anyone considered modeling the effect currently explained via dark matter as a new kind of force or field? Like a distinct force generated by mass and its relationship to space time? This wouldn’t be modified gravity but a proposal for an entirely new force whose effect is what we currently explain with the “fudge factor” of dark matter. From the rough picture I do have of dark matter this force would be one whose relationship to distance is different from the usual inverse square law that governs forces. That would be weird but maybe no weirder than particles that can never be detected or MOND.

mr_mitm 4y ago
Someone has: https://en.wikipedia.org/wiki/Self-interacting_dark_matter https://en.wikipedia.org/wiki/Self-interacting_dark_matter They even think about dark chemistry: https://iopscience.iop.org/article/10.3847/1538-4357/ac75ef https://iopscience.iop.org/article/10.3847/1538-4357/ac75ef Didn't have much support last time I checked.
igiveup 4y ago
If the unmodified gravity and this new force always oocur together, why not just call them one force? What is it that makes them "distinct"?
- api 4y ago
  Do we know they always occur together?
SAI_Peregrinus 4y ago
"Dark matter" implies a new field. Or rather, a new field or force that affects gravity implies some sort of interaction exactly like a massive particle that interacts only gravitationally. Particles are just localized disturbances in fields (in quantum field theory), and new fields can have such disturbances and thus have particles. In this (trivial) sense, MOND is a type of "dark matter" theory that posits a particle with only gravitational interactions. Of course we don't have a quantum field theory for gravity, so the above is hand-waving away a HUGE issue of what that new field would be like, how its particles would act, etc, since we don't even know what the quantum gravitational field is like and what its particles are like (assuming such a thing even makes sense).

by api 4y ago

mr_mitm 4y ago

Someone has: https://en.wikipedia.org/wiki/Self-interacting_dark_matter https://en.wikipedia.org/wiki/Self-interacting_dark_matter They even think about dark chemistry: https://iopscience.iop.org/article/10.3847/1538-4357/ac75ef https://iopscience.iop.org/article/10.3847/1538-4357/ac75ef Didn't have much support last time I checked.

igiveup 4y ago

If the unmodified gravity and this new force always oocur together, why not just call them one force? What is it that makes them "distinct"?

api 4y ago
Do we know they always occur together?

SAI_Peregrinus 4y ago

"Dark matter" implies a new field. Or rather, a new field or force that affects gravity implies some sort of interaction exactly like a massive particle that interacts only gravitationally. Particles are just localized disturbances in fields (in quantum field theory), and new fields can have such disturbances and thus have particles. In this (trivial) sense, MOND is a type of "dark matter" theory that posits a particle with only gravitational interactions. Of course we don't have a quantum field theory for gravity, so the above is hand-waving away a HUGE issue of what that new field would be like, how its particles would act, etc, since we don't even know what the quantum gravitational field is like and what its particles are like (assuming such a thing even makes sense).