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I always wondered about this. If changes in gravity propagated faster than light, could you build a transmitter by modulating a gravity field by colliding matte
by yeureka 13y ago
I always wondered about this. If changes in gravity propagated faster than light, could you build a transmitter by modulating a gravity field by colliding matter with anti-matter?
- jswhitten 13y agoHow would that modulate a gravity field? If you're thinking that the matter and antimatter have gravity and that gravity disappears when they annihilate because their mass is gone, that's not the case. All energy and momentum produces gravity, not just mass.
- stcredzero 13y agoYou could only modulate gravity as fast as you could move energy close to you or far away from you. An implausibly powerful gamma ray flashlight flicking on and off would let you do this. Get the beam powerful enough, and it will have a gravitational field.
- gliese1337 13y agoGet the beam powerful enough and it will have meaurable gravitational field. All beams of any intensity technically do contribute some, albeit infinitesimal, component to the gravitational field. It's a fun exercise to calculate just how strong a laser beam you'd need to have to make a black hole entirely out of photons.
- stcredzero 13y agoA black hole can actually cause an additional singularity due to the blueshifting of infalling light. IIRC, one researcher studied this phenomenon and called it a "blue sheet."
- nkuttler 13y agoThere was this one russian http://en.wikipedia.org/wiki/Eugene_Podkletnov#Podkletnov.27s_gravity_shielding_experiments http://en.wikipedia.org/wiki/Eugene_Podkletnov#Podkletnov.27..., but nobody has yet managed to replicate his results.
- yeureka 13y agoMy understanding of physics is very poor, I was under the impression that only mass produced gravity.
- RuggeroAltair 13y agoJust to make it clear. If gravity was propagating faster than light, then general relativity for how we conceive it would have to be reformulated. It would be similar to the problem of if neutrinos were actually going faster than the speed of light (they're not).