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Einstein's Apple: His First Principle of Equivalence

Engelbert L. Schucking·Eugene J. Surowitz
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Abstract

After a historical discussion of Einstein's 1907 principle of equivalence, a homogeneous gravitational field in Minkowski spacetime is constructed. It is pointed out that the reference frames in gravitational theory can be understood as spaces with a flat connection and torsion defined through teleparallelism. This kind of torsion was introduced by Einstein in 1928. The concept of torsion is discussed through simple examples and some historical observations.

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Engelbert L. Schucking, Eugene J. Surowitz. 2012-08-09. Einstein's Apple: His First Principle of Equivalence. https://arxiv.org/abs/gr-qc/0703149

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