3 ms·
Galaxies are drawn toward each other due to gravity, but when they meet ordinary matters "stop" because lumps of gas plow against each other, causing them to lo
by yongjik 6y ago
Galaxies are drawn toward each other due to gravity, but when they meet ordinary matters "stop" because lumps of gas plow against each other, causing them to lose energy and stop.
Dark matter doesn't interact with anything else (or even itself) so they pass right through each other.
- chadcmulligan 6y agoSo does that mean there are some galaxies without dark matter - because of a previous collision? And then some dark matter only galaxies, because they left their galaxy behind? I suppose this is unknown - but does the dark matter reappear in the galaxy later somehow, or it's left behind forever? Edit: well there are galaxies without dark matter (maybe) [1] and there are dark matter galaxies [2] [1] https://www.space.com/19-galaxies-missing-dark-matter.html https://www.space.com/19-galaxies-missing-dark-matter.html [2] https://www.space.com/33850-weird-galaxy-is-mostly-dark-matter.html https://www.space.com/33850-weird-galaxy-is-mostly-dark-matt...
- corty 6y agoreappearance is possible in collision sims, but the timescale is too long to be easily observable.
- The_rationalist 6y agoI remember that a few years ago a galaxy had been discovered with a claimed ~>90% of dark matter. Personally I believe the theory is epistemologically weaker than MOND