Dark Matter

Since the original suggestion of the
existence of dark matter,
the evidence has become overwhelming.
The question has changed from
"Does dark matter exist?" to
"What is this most common of substances?"
G.Jungman, M.Kamionkowski, K.Griest

In the beginning of thirties of the last century a Swiss cosmologist F. Zwicky applied the virial theorem (in the gravitational field $2\langle E_{kin}\rangle+\langle E_{pot}\rangle=0$) in order to estimate the mass of the Coma cluster (Berenice's Hair). He was surprised to discover that in order to support the finite motion of the galaxies belonging to the cluster, its mass must be at least two orders of magnitude greater than the observed mass (in the form of luminous galaxies). He was the first to introduce the term "dark matter" which strongly entered the vocabulary of modern cosmology. At present the term is understood as the non-baryon matter component which neither emits nor absorbs electromagnetic waves in any range.