Observation of negative-frequency waves in a water tank: A classical analogue to the Hawking effect?
Philbin, Thomas G.
New Journal of Physics
Institute of Physics
The conversion of positive-frequency waves into negative-frequency waves at the event horizon is the mechanism at the heart of the Hawking radiation of black holes. In black-hole analogues, horizons are formed for waves propagating in a medium against the current when and where the flow exceeds the wave velocity. We report on the first direct observation of negative-frequency waves converted from positive-frequency waves in a moving medium. The measured degree of mode conversion is significantly higher than expected from theory.
Copyright © 2008 IOP Publishing
Open Access journal
Vol. 10, article 053015