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I asked mostly for the conversation value, I certainly am not sure of anything myself! Well, a really spread out distribution across the universe would explain

I asked mostly for the conversation value, I certainly am not sure of anything myself! Well, a really spread out distribution across the universe would explain that. It would, but then there's the 'why' it's spread out. Maybe that's answered in the particle predictions but something is keeping it apart, but doesn't affect visible matter in the same way. It's obviously spread out just enough to not be clumpy, but not so much that it can't pull a galaxy together. If it were everywhere it wouldn't have the effect we think we see.

hugh_ 17y ago
Ordinary matter forms dense clumps like planets and stars because it's sticky. Atoms may be attracted to one another by gravity, but in order to get them to actually stick together into dust grains, planets, stars et cetera, you need them to collide inelastically, and that requires the electromagnetic force. Two dark-matter particles in the void will be attracted to each other (slightly) by gravity, but when they meet they'll just sail straight on through one another without colliding. This prevents the formation of small-scale (ie sub-galactic scale) dark matter clumps.