The Singing Cymbal: Is It Really Photon Momentum?

摘要

A simple demonstration that is occasionally used in the classroom to show that light carries momentum involves making an orchestral cymbal audibly ring using light from a common photoflash. A metal plate or a piece of foil can also be used; however, it appears that many people use a cymbal because the sound is easily heard at a reasonable distance. It is such an impressive example of the effects attributable to photon momentum that it is posted on the CERN website for educational resources under the name "singing cymbal."~1 Although it is an impressive demonstration, a series of simple classroom experiments can show that the sound of the singing cymbal is not due to the transfer of photon momentum.