Supermassive black holes, or SMBHs, are black holes with masses that are several million to billion times the mass of our sun. The Milky Way hosts an SMBH with mass a few million times the solar mass. Surprisingly, astrophysical observations show that SMBHs already existed when the universe was very young. For example, a billion...
Anew theory about the nature of dark matter helps explain why a pair of galaxies about 65 million light-years from Earth contains very little of the mysterious matter, according to a study led by a physicist at the University of California, Riverside. Dark matter is nonluminous and cannot be seen directly. Thought to make up...
