W. G. Unruh

William G. Unruh
Dr. Unruh teaching "PHYS 407 - Introduction to General Relativity" at University of British Columbia (Dec. 2008)
Born	William George Unruh 28 August 1945(1945-08-28) Winnipeg, Manitoba
Residence	Canada
Citizenship	Canada
Nationality	Canada
Fields	Theoretical physics Relativity Quantum Mechanics
Institutions	University of British Columbia
Alma mater	University of Manitoba Princeton University
Doctoral advisor	John Archibald Wheeler

Dr. Unruh teaching PHYS 200 - Introduction to Relativity and Quanta - at UBC (Circa 2006)

William George Unruh (born August 28, 1945) is a Canadian physicist at the University of British Columbia, Vancouver, who discovered the Unruh effect. Unruh was born in Winnipeg, Manitoba. He obtained his B.Sc. from the University of Manitoba in 1967, followed by an M.A. (1969) and Ph.D. (1971) from Princeton University, New Jersey, under the directions of Professor John Archibald Wheeler.

Areas of research

Unruh has made seminal contributions to our understanding of gravity, black holes, cosmology, quantum fields in curved spaces, and the foundations of quantum mechanics, including the discovery of what is now known as the Unruh effect.

Unruh also appears to be interested in music and teaches the Physics of Music.

The Unruh effect

Main article: Unruh effect

The Unruh effect, which Unruh discovered in 1976, is the prediction that an accelerating observer will observe black-body radiation where an inertial observer would observe none. In other words, the accelerating observer will find himself or herself in a warm background. The quantum state which is seen as ground state for observers in inertial systems is seen as a thermodynamic equilibrium for the uniformly accelerated observer. The Unruh effect therefore means that the very notion of vacuum depends on the path of the observer through spacetime.

The Unruh effect can be expressed in a simple equation giving the equivalent energy kT of a uniformly accelerating particle (with a being the constant acceleration), as:

$kT = \frac{\hbar a}{2\pi c}$

Awards

• Rutherford Memorial Medal of the Royal Society of Canada, 1982
• Herzberg Medal of the Canadian Association of Physics, 1983
• Steacie Prize, 1984
• Steacie Fellowship, 1984–1986
• BC Science Council Gold Medal, 1990
• Appointed a Fellow of the Royal Society, July 13, 2001

Publications

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

External links

• University of British Columbia Physics Dept. page
• Dr. Unruh's course webpage - PHYS 200 Introduction to Relativity and Quanta
• UBC Theoretical Physics Homepage - a web server ran by Unruh