I thought this was interesting.
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I do not think it is accurate to say that Mass and energy are interchangable. Some other thing must be added to convert one to the other, like the way we convert water and ice. It would follow from my viewpoint that energy has not been shown to have gravity. What "gravity has gravity" means is beyound me, and I admit it.
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mass can generate energy due to gravity.
the center of the earth is verry hot because the pressures exerted on the center.
everything from the edge of space downward to the center presses in on the center.
some say that gravity becomes weaker closer to the center but how can that be?
if so then gravity is in layers as DA says.
if gravity becomes weaker closer to the center then we are measuring gravity wrong.
because gravity is what we use to measure a object as it falls.
and if an object fell far enought then its acceleration due to gravity would diminish.
it would slow its acceleration.
