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  Does an apple "falling" from a tree move only in the time direction in curved spacetime?

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Does it appear to a distant observer that the distance between the earth and the apple is decreasing as they move along their geodesics but only in the time direction , and in reality neither the earth or the apple move through space?

Closed as per community consensus as the post is not graduate-level
asked Nov 25, 2018 in Closed Questions by anonymous [ no revision ]
recategorized Nov 27, 2018 by Dilaton

not graduate+ level. Users with 500+ reputation may vote here to close. 

PhysicsOverflow is a site for advanced physics. Please ask elementary 
question in other online platforms that value such questions. 

I bet you can't answer it correctly..

Your statement reveals elementary problems in understanding the notions involved. Motion ''in time only'' depends on the coordinate system used, and would imply in this coordinate system that the spatial distance does not change, which is obviously wrong.

1 Answer

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In GR "moving through space" is implied; otherwise the notion of space would be useless. You mistake a "free motion" in space (=along geodesics) for "no motion at all".

answered Nov 27, 2018 by Vladimir Kalitvianski (112 points) [ no revision ]




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