nprofile1qy2hwumn8ghj7un9d3shjtnddaehgu3wwp6kyqpqknzsux7p6lzwzdedp3m8c3c92z0swzc0xyy5glvse58txj5e9ztqaufa4k (nprofile…fa4k)
I have another question about your book. On p 379 you write the following:
"Einstein's explanation of gravity says, first of all, that gravity is not really a force! In other words, the natural state of motion is free fall, and it takes a force to create a deviation from free fall. To put it dramatically but quite correctly, there is not really a force of gravity pulling us down as we stand on the floor; instead, the electromagnetic repulsion of the molecules on the floor are pushing our feet up! (It is amusing to get into the habit of feeling things this way.) Geometrically speaking, free fall traces out a path in spacetime that is as straight as possible at every step of the way, a so-called 'geodesic'.• It is only the curvature of spacetime that makes these geodesics look different from straight lines in Minkowski spacetime. For this reason, the very notion of a 'gravitational field', as some sort of force field á la Newton, is misleading and not really appropriate to general relativity. There is only the metric, which, as we now show, determines the notion of a geodesic via the Levi-Civita connection."
Given that gravity "is not a force", then why have physicists put so much effort into attempting to quantise gravity? If the above is correct, surely the attempt to define the graviton in terms of a quantum field theory must prove fruitless?
Tony Vladusich /
npub173…rfeej
2025-02-16 01:50:12
Author Public Key
npub173x9mumh8heh8ndfsc07j2gylwtx950vy5u9e98730ksg4thlwpqgrfeejPublished at
2025-02-16 01:50:12Event JSON
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