Dark matter makes up most of the mass in galaxies and galaxy clusters. In fact, scientists estimate that ordinary matter makes up only about 5% of the universe, while dark matter makes up about 27%.

Few things in the universe are as perplexing as dark matter — the invisible and exotic “stuff” that is thought to make up most of the matter in galaxies. The theory goes like this: To reconcile our ...

Dark matter is a real pain in the neck. The term dark matter itself refers to a hypothetical substance that seems to solely interact with the rest of the universe via gravity and to serve as the ...

The universe is packed with riddles, but few are as stubborn or as fascinating as dark matter. First proposed in 1933 by astronomer Fritz Zwicky, this elusive substance refuses to play by the rules: ...

Two recent studies by Professor Stefano Profumo at the University of California, Santa Cruz, propose theories that attempt to answer one of the most fundamental open questions in modern physics: What ...