- #1
Xilor
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Because gravity travels at the speed of light in GR, there seem to be a few possible places where gravity could pull you towards if dealing with some massive object in some orbit, which one of these is predicted?1. To the position where you see the object (the place where the object used to be)
Or one of these options where you are pulled towards the expected present location of the object:
2. Using the Newtonian perspective of a straight line (wherein orbits are only due to acceleration), using the perspective of 'present location' in your reference frame.
3. Using the GR perspective of a straight line (wherein gravity involves moving along straight lines), using 'present location' in your reference frame.
4. Using Newtonian lines, using 'present location' as seen in some other frame, like that of the object.
5. Using GR lines, using 'present location' as seen in some other frame, like that of the object.
Or:
6. Where it 'actually' is (in some frame?), after accounting for factors like non-gravitational acceleration etc. Aka, some form of instantaneous-like position.It feels there's some potential problems with all of them, so I can't figure this one out nor find any conclusive statements elsewhere, except that it probably isn't option 1.
And followup question, has whatever answer is predicted actually been shown experimentally/through data? I imagine that with the difficulty of measuring gravitational acceleration to one particular object, and with the low velocities in our area of space the minimal differences would actually be rather hard to detect.
Or one of these options where you are pulled towards the expected present location of the object:
2. Using the Newtonian perspective of a straight line (wherein orbits are only due to acceleration), using the perspective of 'present location' in your reference frame.
3. Using the GR perspective of a straight line (wherein gravity involves moving along straight lines), using 'present location' in your reference frame.
4. Using Newtonian lines, using 'present location' as seen in some other frame, like that of the object.
5. Using GR lines, using 'present location' as seen in some other frame, like that of the object.
Or:
6. Where it 'actually' is (in some frame?), after accounting for factors like non-gravitational acceleration etc. Aka, some form of instantaneous-like position.It feels there's some potential problems with all of them, so I can't figure this one out nor find any conclusive statements elsewhere, except that it probably isn't option 1.
And followup question, has whatever answer is predicted actually been shown experimentally/through data? I imagine that with the difficulty of measuring gravitational acceleration to one particular object, and with the low velocities in our area of space the minimal differences would actually be rather hard to detect.