W. G. Unruh

William G. Unruh ( born August 21, 1945 in Winnipeg, Manitoba, Bill Unruh ) is a Canadian theoretical physicist and discoverer of the Unruh effect.


He studied at the University of Manitoba ( BSc 1967) and then at Princeton University, New Jersey (Master of Arts, 1969), where he received his doctorate in 1971.

In 1974 he was appointed as Assistant Professor at McMaster University. In 1976 he moved to the University of British Columbia, where he holds a chair since 1982. In addition, Unruh in 1985 as the first Director of the " Cosmology and Gravity " program of the Canadian Institute for Advanced Research ( CIAR ) called (until 1996 ).


Unruh has made pioneering contributions to the understanding of gravity, black holes, cosmology and the foundations of quantum mechanics. Best known is his well-known as Unruh effect prediction that an accelerated observer, what would be defined in an inertial system as a vacuum, as a heat bath with a temperature dependent on the acceleration (and the corresponding black-body radiation) would perceive.

Currently, he is concerned with the gravitational properties of cosmic strings, aspects of quantum gravity to understand the earliest moments of the universe as well as questions from quantum information theory.

Unruh also deals with acoustics ( he lectured on the physics of musical instruments ) and proposed in 1981 an acoustic analog of black holes before, "sonic black holes " (from his "dumb holes" called ) that occur in liquids, which in itself move in space by an audible " event horizon " separate areas once at a speed below the local speed of sound, and on the other hand supersonic speed.


Unruh has received for his research numerous awards and prizes, including the Rutherford Medal of the Royal Society of Canada (1982 ), the Herzberg Medal of the Canadian Association of Physicists (1983 ), the Killam Research Prize from the University of British Columbia (1990 ) and a CAP / CRM price in Mathematical Physics ( 1995).

He is a member of the Royal Society of Canada, the American Physical Society and the Royal Society of London.


  • William G. Unruh: Notes on Black Hole Evaporation. Phys. Rev. D 14 870, 1976 ( English)
  • William G. Unruh, Robert M. Wald: Time and the Interpretation of Canonical Quantum Gravity. Phys. Rev. D 40 2598 1989 ( English)
  • William G. Unruh, Wojciech H. Zurek: Reduction of a wave packet in quantum Brownian motion. Phys. Rev. D 40 1071 (English)
  • William G. Unruh, M. Choptuik: An introduction to the Multi -Grid Method for Numerical relativists. General Rel & Grav 18 813 1985 (English)

Pictures of W. G. Unruh