Andres Espineira's List: dark matter

• Most of the stuff in clusters of galaxies is invisible and, since these are the  largest structures in the Universe held together by gravity, scientists then  conclude that most of the matter in the entire Universe is invisible.

• Scientists using different methods to determine the mass of galaxies have found a discrepancy that suggests ninety percent of the universe is matter in a form that cannot be seen. Some scientists think dark matter is in the form of massive objects, such as black holes, that hang out around galaxies unseen.
• Other scientists believe dark matter to be subatomic particles that rarely interact with ordinary matter.
• implies
• But something supplied the initial gravity to allow galaxies to form. Physicists suggest dark matter WIMPs as the solution.

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