Degeneracy
A state of matter characterized by extreme compactness or density.
Degenerate matter can be more than a million times more dense than water.It is
so compact that it's behavior can only be described quantum mechanically.
Neutron stars are composed of degenerate matter. The pressure created by their
gravitational collapse is so great that the protons and electrons in atoms
are fused together, resulting in a whole star composed entirely of neutrons.
