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Name: lord corwin
Status: N/a
Age: N/A
Location: N/A
Country: N/A
Date: Around 1993

Is it not a basic assumption in relativity theory an object is motionless relative to itself? If this is so, should this not also include spin? It seems to me that with only itself as a reference, an object cannot be spinning, but if this were so, then I would not understand how central force could work, or even exist.

Well, relativity and quantum mechanics have not been reconciled ...yet... Actually, though, your statement is not really true. A point object ought to be motionless with respect to itself, yes, but an extended object can be rotating, and there is a real meaning to rotation in our universe. Relativity eliminates the idea of a special frame of reference for translational motion, but there is still a special rotational frame of reference in our universe, and an object that is rotating relative to this frame really does experience the centripetal acceleration and corresponding apparent centrifugal force that tends to pull rotating objects apart. And, I guess, an elementary particle with spin really has some angular momentum.

Arthur Smith

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