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I remember looking into the question of gravitation transmission before. As far as I could amatueurly determine, gravitational transmission is an unanswered qu

I remember looking into the question of gravitation transmission before. As far as I could amatueurly determine, gravitational transmission is an unanswered question. This is to say, if the sun "dissapeared" would the Earth feel it straight away (because spacetime had been altered) or would it take as long as the time for light to reach us because gravitrons (if they exist) could only travel as fast as the speed of light? I'm aware of the whole limit on information transmission so I assume the latter, but I thought it was still unanswered.

derefr 17y ago
I think the real problem with that question is deciding exactly what you mean by "disappear." If you blow the sun up, it still has all its mass, it's just spreading apart, and the effect this has on Earth can be graphed continuously. Likewise if you just move it somewhere else really fast (because you can't move it faster-than-light.) If you convert it completely into energy, by the mass-energy equation, it still has all its mass. Thinking about gravity becomes a lot simpler when you realize that every one of those particles of the Sun is quantum-entangled with all the particles of the Earth. If you want to "remove" the Sun, you have to decide what that means for the decoherence of the configuration subspace consisting of (what was previously) Sun + Earth. Configurations only evolve toward more definite subsections of themselves, not completely "new," remote amplitudes. Also, as far as we can tell, decoherence is computable from the completely local neighborhood of the amplitude-mass in question. Thus, gravitational transmission has to take some amount of time, in the same way that one domino can't knock down another across the room instead of going through the dominos in-between. The interesting thing is that some of the particles of the Earth (analogously, the intermediate dominos) would be immediately affected—but it would take Au/C before enough of them were affected that that decoherence would become detectable.
- nopassrecover 17y ago
  Wait so gravity is quantum entanglement? I've never been given that view before. If I understand you correctly, gravity does have an effect faster than the speed of light but there is no detectable effect faster than the speed of light?

derefr 17y ago

I think the real problem with that question is deciding exactly what you mean by "disappear." If you blow the sun up, it still has all its mass, it's just spreading apart, and the effect this has on Earth can be graphed continuously. Likewise if you just move it somewhere else really fast (because you can't move it faster-than-light.) If you convert it completely into energy, by the mass-energy equation, it still has all its mass. Thinking about gravity becomes a lot simpler when you realize that every one of those particles of the Sun is quantum-entangled with all the particles of the Earth. If you want to "remove" the Sun, you have to decide what that means for the decoherence of the configuration subspace consisting of (what was previously) Sun + Earth. Configurations only evolve toward more definite subsections of themselves, not completely "new," remote amplitudes. Also, as far as we can tell, decoherence is computable from the completely local neighborhood of the amplitude-mass in question. Thus, gravitational transmission has to take some amount of time, in the same way that one domino can't knock down another across the room instead of going through the dominos in-between. The interesting thing is that some of the particles of the Earth (analogously, the intermediate dominos) would be immediately affected—but it would take Au/C before enough of them were affected that that decoherence would become detectable.

nopassrecover 17y ago
Wait so gravity is quantum entanglement? I've never been given that view before. If I understand you correctly, gravity does have an effect faster than the speed of light but there is no detectable effect faster than the speed of light?