The Chinese were the first to
observe that stars have a life span. With the first observation of a supernova
in the crab nebula in 1054 AD, the Chinese were the first to grasp the idea of
stars undergoing death. Since that observation, astronomers have discovered the
many forms which stars take on after death. These include white dwarfs, black
holes, and neutron stars.   Neutron
stars form after the collapse of an extremely massive star. The neutron star
consists of tightly bound matter that is under high pressure. In these highly
dense conditions the matter desires to be in the lowest energy state possible.
Through the extreme heat that is generated in the collapse of a star, the
fusion of subatomic particles is possible. When the matter desires to enter into
the lowest energy state it becomes neutrons. Since pressure and heat keep
building throughout the course of collapse, the subatomic particles find it
easier to form neutrons. During these extreme conditions, protons and electrons
fuse together to form both neutrons and neutrinos. After the collapse, neutrons
gather together to form the neutron star and the neutrinos scatter outward.