Measurement of Hawking Radiation in an analog system

From QCLab
  • Speaker: Prof. Unruh, William (University of British Columbia, USA)
  • Date: Friday July 4, 2014 11:00

Hawking's predictions that black holes should radiate was one of the most surprizing result of late 20th century physics.Unfortunately, finding small black holes whose radiation would be measureable seems impossible. In 1981 I showed that there are analog systems, systems with horizons to the travelling of other kinds of waves (sound, light, surface waves,...) where the predictions of Hawking should also follow-- those systems should also emit quantum noise with a thermal spectrum. I will describe and experiment we carried out in which that thermal spectrum was measured for surface waves on flowing water. While the qunatum noise itself was unmeasureable, the stimulated emission ( which Einstein showed was closely related to the spontaneous emission) was measureable, and showed tha the quantum noise has a thermal spectrum. This talk illustrates the amazing feature of physics to reveal close ties between areas one would never have suspected were related.