| | In the 1980s astronomers discovered that the visible matter in rotating galaxies has insufficient [[gravity]] to hold the galaxy together. The term ''dark matter'' refers to whatever is generating the extra [[gravity]]. | | In the 1980s astronomers discovered that the visible matter in rotating galaxies has insufficient [[gravity]] to hold the galaxy together. The term ''dark matter'' refers to whatever is generating the extra [[gravity]]. |
| − | Academic [[physicist]]s feel that most of the [[mass]] in a [[galaxy]] is unseen dark matter, and that known substances like [[neutrino]]s, [[black holes]], and dead [[star]]s are insufficient. Many physicists believe that the dark matter is some as-yet-undiscovered subatomic particle, such as the axion, Higgs, or lightest supersymmetric particle.
| + | Many astro[[physicist]]s say that most of the [[mass]] in a [[galaxy]] is unseen dark matter, and that known substances like [[neutrino]]s, [[black holes]], and dead [[star]]s are insufficient. They think that the dark matter is some as-yet-undiscovered subatomic particle, such as the axion, Higgs, or lightest supersymmetric particle. Others say that there may be some other explanation, such as a modification of the law of gravity. |