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timmdeeg

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https://www.physicsforums.com/threads/rod-falling-radially-towards-the-center-of-a-mass.871169/

I'm now puzzled by the question, what happens to the rod during his radial fall through the event horizon and what would the hypothetical observer at ##r=2M## measure.

Let's consider ##M## large enough to prevent any damage of the rod. Remembering said discussion, there is a "force-free" point somewhere on the rod, also called "locus of no acceleration". I think an observer at a constant radius ##r## will measure a radial velocity ##-\sqrt{2M/r}## of the force-free point only but of the low end a lower und for the top end a higher velocity compared to that. But if correct, would this be valid for the event horizon too? It seems implausible however, because it seems to imply that the low end would fall through the event horizon with ##v<c## and the top with ##v>c##.

Any help is appreciated.