Why do scientists care about dark energy and dark matter?

Scientist want to understand, and to describe, the universe. If we understand something, we can make predictions from our understanding. read more

Dark Energy, Dark Matter In the early 1990s, one thing was fairly certain about the expansion of the universe. It might have enough energy density to stop its expansion and recollapse, it might have so little energy density that it would never stop expanding, but gravity was certain to slow the expansion as time went on. read more

Dark matter emits no light, and cannot be directly observed, but scientists think that it and dark energy make up most of the mass of the universe. Dark matter emits no light, and cannot be directly observed, but scientists think that it and dark energy make up most of the mass of the universe. read more