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Physics, Astronomy & Cosmology / Re: Are galaxies bigger on the inside and galactic πs LESS than 3.14?
« on: 13/04/2021 14:20:06 »
The graphic is massively exaggerated, illustrating why it's probably not a good idea to get your science from social media. Except within the event horizon, a black hole bends space no more than the same mass that is not in a black hole. In other words, if our sun was compressed to a black hole, no orbit of anything would change and the only way we'd notice is:
"Hey, Who turn out the lights?" - proper Dave.
The black hole in the center of our galaxy is tiny and comprises less than 0.000003 of the mass of the galaxy. The bending shown in the picture is nonsense. Yes, they take bending of spacetime into account when computing orbits and such, but the effect is so negligible that it takes very fine measurements of something very close (S2) to the black hole to detect the difference from Newtonian orbital motion.
It has also been measured in Mercury due to the precession of the orbit, but S2 has I think a 17 year orbit and it takes a seriously long time to get precession numbers from it.
"Hey, Who turn out the lights?" - proper Dave.
The black hole in the center of our galaxy is tiny and comprises less than 0.000003 of the mass of the galaxy. The bending shown in the picture is nonsense. Yes, they take bending of spacetime into account when computing orbits and such, but the effect is so negligible that it takes very fine measurements of something very close (S2) to the black hole to detect the difference from Newtonian orbital motion.
It has also been measured in Mercury due to the precession of the orbit, but S2 has I think a 17 year orbit and it takes a seriously long time to get precession numbers from it.
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