4 ms·
Curvature due to gravity does not depend on mass, which is kind of hinted at when mass cancels in F=ma for that force.
by sixo 6y ago
Curvature due to gravity does not depend on mass, which is kind of hinted at when mass cancels in F=ma for that force.
- dreamcompiler 6y agoCurvature due to gravity depends entirely on mass. No mass = no spacetime curvature. In this case, the mass of the Earth is causing the curvature.
- smallnamespace 6y agoSlight correction: curvature depends on the stress-energy tensor, of which energy is a component. A more energetic particle of the same mass will have a very slightly higher gravitational attraction.
- dreamcompiler 6y agoYes indeed. Thanks.
- thewakalix 6y agoThe curvature depends on the mass of the earth, but it _doesn't_ depend on the mass of the photon/ball.
- dreamcompiler 6y agoThe curvature does indeed depend on the ball's mass. The contribution to spacetime curvature the ball's mass brings to the table is extremely small compared to that of the earth, and the contribution that comes from the (massless) photon's energy[0] is smaller still, but they both influence the spacetime curvature. [0] Photons bend spacetime according to GR, although as far as I know this has not been proven experimentally. We'll probably need a theory of quantum gravity to be sure.
- thewakalix 6y agoI’d think that the curvature of spacetime due to the ball’s mass wouldn’t affect the ball’s trajectory, for similar reasons as why the electric field from a charged particle doesn’t move the particle itself.