I Free fall not accelerating but standing on Earth accelerating

How does this work exactly? I can understand depending on frame of reference but I read that Einstein stated there is a right way to think about that based on inertial and non-inertial frame of references.

Simon Bridge

Science Advisor
Homework Helper
In physics, if there is no way to distinguish two things, they are the same.

If you are in a box that is accelerating, what you experience is being pushed to one side of the box.
You would intuitively assign that side the special label "floor", and how hard you press into it would be your "weight".

This is also what you experience standing in a box on the Earth, but not when you are in a box in freefall... it follows that standing on the earth is not distinguishable from a situation where you are accelerating while freefall is not distinguishable from the situation where you are not accelerating.

That's not all there is to it - but it's a starting point.


Science Advisor
How does this work exactly?
Look up "equivalence principle" and "proper acceleration" vs. "coordinate acceleration".

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