This is related to this question which provided evidence about dark matter, and this question which asked what would happen if dark energy started disappearing.

This question assumes that dark matter is an actual real 'thing' of 'something', just like any other known particle.

The question I wanted to ask is, what would happen if all dark matter was removed from the universe?

Would the galaxies rotation speeds just slow down or are there any other known (or realistically assumable) effects (locally, or on the universe scale)?

Update: what I am looking for is are the 'beneficial functions' that does dark matter provide, sort of like its 'raison d'être'.

  • $\begingroup$ HBO, "The Leftovers" . That's only partly a joke. $\endgroup$ – Carl Witthoft Oct 29 '15 at 18:07
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    $\begingroup$ rotations will not slow down, rather the galaxies and galactic cumulus would spread apart (but nothing will happen with smaller objects such as stars) $\endgroup$ – user83548 Oct 29 '15 at 18:26
  • $\begingroup$ All else being equal, if you remove dark matter from the universe, then there wouldn't be a universe as you know it. The remaining matter would not have enough gravity to form galaxies and stars and the universe would be accelerating much faster. To be honest, though, you can't do this. Dark matter exists for some very deep reason which we just don't know, yet, and you can't simply cut it out and do a "what if" analysis in science. That's by definition of science as a rational explanation system for the observed world. $\endgroup$ – CuriousOne Oct 29 '15 at 20:24
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    $\begingroup$ @CuriousOne, you seem to don't like experiences of thought, how useful they can be to figure the role of things for many people :-) . A way to understand the role of dark matter in the balance is to evaluate the unbalance that would result in the proposed case. So that's not a bad question. ;-) $\endgroup$ – Fabrice NEYRET Oct 29 '15 at 23:04
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    $\begingroup$ @FabriceNEYRET: You have to forgive me. I have been a working experimental physicist who was focused on producing data about the real universe. That is what working physicists do. Of course there is a place for philosophers who think about all the other things that don't exist. That's all fun and games, but it is not physics. $\endgroup$ – CuriousOne May 16 '16 at 9:36

If anything I believe that without dark matter everything in the universe would be accelerated as someone pointed out. But reason being is that particles that form anything with a gravitational force possibly feed off of that dark energy and is what makes it has it own gravity. That being said maybe dark matter is attracted to different substances and masses therefore effecting gravity and messing up orbits or creating new ones.

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    $\begingroup$ Answers aren't really for blind speculation. $\endgroup$ – JMac Mar 14 '17 at 18:15

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