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To any single observer that crosses, I agree with your statement, but it changes the moment you have two observers. I also agree that at the North Pole, "all di
by gosub100 3y ago
To any single observer that crosses, I agree with your statement, but it changes the moment you have two observers. I also agree that at the North Pole, "all directions are south", but the difference is you are free to move back and forth.
If you picture us in an X-Y plane (which somehow represents all 3 spatial coords), and "up" is the time dimension, then a black hole would be the X-Y plane deformed into a 90-deg "pipe" facing straight down. Once you are in the pipe, your "X-Y" is our "up-down", this is probably the "artifact" you are referring to.
- eigenket 3y ago> If you picture us in an X-Y plane (which somehow represents all 3 spatial coords), and "up" is the time dimension, then a black hole would be the X-Y plane deformed into a 90-deg "pipe" facing straight down. This is not correct, there is no 90 degree bend. Space-time is locally Minkowskian ("flat") at the event horizon. It looks like a sharp 90 degrees turn in some coordinate system, just as when you walk in a "straight line" (a great circle if you prefer) over the north pole you go discontinuously from "walking north" to "walking south" even though your real motion is continuous.