Adapted from Eric's Treasure Trove. Go to original for links shown in blue, and references.

Heisenberg, Werner (1901-1976)

German physicist who in 1925 invented matrix mechanics, the first full version of quantum mechanics.
In 1927, Heisenberg derived the Uncertainty Principle, which states that

$$\Delta p\Delta x \geq {h\over 4\pi}.$$

In 1932 he was awarded the Nobel Prize in physics for this work.

He also developed operator methods for the solution of quantum mechanical problems.
On his death bed, Heisenberg is reported to have said, "When I meet God, I am going to ask him two questions: Why relativity? And why turbulence? I really believe he will have an answer for the first." However, this quote is also attributed to Horace Lamb.

Additional biographies: MacTutor (St. Andrews), the Nobel site, and a major site at AIP Center for History of Physics.

References

Cassidy, D. Uncertainty: The Life and Science of Werner Heisenberg. New York: W. H. Freeman, 1991.

Heisenberg, W. Der Teil und das Ganze: Gesprache im Umkreis der Atomphysik. Munich, Germany: R. Piper, 1969.

Heisenberg, W. The Physical Principles of the Quantum Theory. New York: Dover, 1930.

Powers, T. Heisenberg's War: The Secret History of the German Bomb. New York: Knopf, 1993.