Werner Karl Heisenberg (1901-1976), a German theoretical physicist
was one of the leading scientists of the
20th century. He did important work in nuclear and particle
physics, but his most significant contribution was to the
development of quantum mechanics. He is best known for his
uncertainty principle, which restricts the accuracy with which
some properties of atoms and particles--such as position and
In 1932 he was awarded the Nobel Prize in physics.