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← The Dark-Matter Ages

Northampton's Avatar Jump to comment 19 by Northampton

Comment 18 by dgharmon :

Why doesn't “dark matter” clump?

It does clump because dark matter interacts gravitationally and gravity is ultimately what makes things clump. It does not clump in the way normal matter clumps because dark matter is weakly interacting (two blobs of dark matter would pass right through each other). If two clouds of dust were to head toward each other due to gravitation they would collide and heat up. The conversion of their kinetic energy to heat would slow them down and we get a good clump. Because dark matter is more ghostlike it is less efficient at clumping but it clumps nonetheless.

Now I've said "clump" so much it sounds like a nonsense word.

Tue, 19 Jun 2012 13:56:35 UTC | #947846