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MOND does amazingly well at galactic rotation curves, less well at anything else. If you think it started with Vera Rubin in 1966 MOND seems natural, but if
by PaulHoule 6mo ago
MOND does amazingly well at galactic rotation curves, less well at anything else. If you think it started with Vera Rubin in 1966 MOND seems natural, but if you know that it started with Fritz Zwicky in 1933 than dark matter is easier to believe.
- adgjlsfhk1 6mo agoMOND only really does well on galactic rotation curves because it has free parameters that are tuned to "predict" the correct answer for galactic rotation curves.
- wetpaws 6mo ago[dead]
- dnautics 6mo agoI think you mean LCDM only does well on galactic rotation curves because it has free parameters per galaxy. MOND only has one free parameter, maybe two if you use the MOND+Relativity model that doesn't work.
- drdeca 6mo agoI don’t think these are free parameters in the same sense. Like, if one theory says that a hunk of metal actually is made of many microscopic grains of various sizes and orientations, where the sizes and orientations of these grains has an effect on the behavior of the metal, you don’t count the “the sizes and orientations of these grains” as free parameters, do you?
- adgjlsfhk1 6mo agoYou would if you didn't have any ability to observe those sizes and orientations.
- jahnu 6mo agoThere are galaxies that appear to be free of dark matter and rotate accordingly. How does MOND account for that? My understanding is that these observations are a fatal blow to any serious MOND models.
- yxhuvud 6mo agoMOND obviously don't have to account for the lack of dark matter, as all galaxies lack it under MOND. You have to actually do the calculations and compare what MOND output to the observed behaviour of the galaxies in question.
- firebot 6mo agoMOND reduces but doesn't eliminate the need for dark matter.