4 ms·
To me it seems the equivalence principle is actually false. It was an inspiration to come up with general relativity but the resulting theory supports it kind o
by cjfd 3y ago
To me it seems the equivalence principle is actually false. It was an inspiration to come up with general relativity but the resulting theory supports it kind of, but not really. To start out with, it only holds either looking at an infinitesimal extent of space or in a homogeneous gravitational field. As soon as the gravitational field cannot be seen as homogeneous, you are going to know that you are falling instead of floating through space. E.g., spaghettification near a black hole. Another case in point is the somewhat well-known question if a falling electron radiates. Yes, it should, but that violates the equivalence principle.
- SamBam 3y agoMy understanding is that the equivalence principle only applies to a specific, local region of space time, and this region could be arbitrarily small. Tidal forces are only measurable across something with size, by measuring a difference between one point and another. Even if your body is being spaghettified, an arbitrarily small region of your body still can't tell that it's under anything but freefall.