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I don’t know much about General Theory Of Relativity but I have heard that it does not consider gravitational fields like Newtonian Mechanics.

If an object were to be free falling, then according to general relativity that object would be in an inertial frame and everything around it will be accelerating at g rate. So, if everything around is accelerating at g,then they must be gaining velocity, meaning they must be gaining energy or mass?

This is obviously not true, so I am confused as to how this works out.

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  • $\begingroup$ Kinetic energy is frame dependent. $\endgroup$ – Adrian Howard Oct 25 '20 at 16:39
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In the frame of reference of a freely falling body, you are gaining speed or energy(assuming you are standing on the ground), because the normal force is accelerating you and doing work on you(in that frame there will be no gravitational force). If that normal force was not there then you to would be in free fall.

Now in your own frame, you are not accelerating, despite there is an upward normal force because there is some force that is similar to a pseudo force acting on you. That is gravity.

Additional Note: One important thing is that Gravitational effects are not exactly equal to the effects caused due to acceleration inside an accelerating frame in space. The equivalence principle works only locally. In a variable gravitational field, we can do nonlocal experiments and find whether it is due to gravity or not. In this example since you are small compared to the radius of the earth, we can assume uniform gravity.

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