Werner Heisenberg was known to the First Doctor as one of the notable scientists in 1933 Germany. (AUDIO: The Alchemists)
Heisenberg's uncertainty principle stated that the very act of measuring something changed its nature. (AUDIO: The Time of the Daleks)
Alistair Gryffen used the exclamation "what the Heisenberg?" to express shock. (TV: Alien Avatar)