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Physics, Astronomy & Cosmology / Re: Have we made any progress understanding why matter causes spacetime to bend?
« on: 12/12/2016 12:42:36 »
Note the word spacetime rather than space. And a good point. We know gravity involves a slowing down of time but I have always wondered if space is really bent.
Einstein used gravity bending light as proof. This with the logic that light has no mass.
Thing is light does have mass. Not admittedly rest mass but E=MC2 rearrange to M=E/C2. If you could put a perfect mirror coating inside a bottle and fill it with photons that is how much the contents would mass.
So when starlight passes the sun (Einstein's proof) gravity is going to bend its path a little, and, conserving momentum the sun must get a bit of a shift too. Admittedly not enough to notice.
Anyway, I sort of suspect that the time dilation is the most fundamental characteristic of gravity. I don't think the speed of time and the speed of light can be separated as at the most basic level everything travels at the speed of light - ether directly, as a standing wave, or some combination.
So, without being able to explain why mass reduces the speed of light it might be possible to simplify the maths by assuming it does. It does explain the pull of gravity. Given E=MC2 then E drops with C inside a gravitational field and that's where the potential energy comes from.
Einstein used gravity bending light as proof. This with the logic that light has no mass.
Thing is light does have mass. Not admittedly rest mass but E=MC2 rearrange to M=E/C2. If you could put a perfect mirror coating inside a bottle and fill it with photons that is how much the contents would mass.
So when starlight passes the sun (Einstein's proof) gravity is going to bend its path a little, and, conserving momentum the sun must get a bit of a shift too. Admittedly not enough to notice.
Anyway, I sort of suspect that the time dilation is the most fundamental characteristic of gravity. I don't think the speed of time and the speed of light can be separated as at the most basic level everything travels at the speed of light - ether directly, as a standing wave, or some combination.
So, without being able to explain why mass reduces the speed of light it might be possible to simplify the maths by assuming it does. It does explain the pull of gravity. Given E=MC2 then E drops with C inside a gravitational field and that's where the potential energy comes from.