|MadSci Network: Physics|
Dear G. M. Saxena: Light and sound waves do exert pressure. How do we observe this pressure? It is by the momentum transfer from the quanta of light; or the momentum transfer from collisions with impinging molecules of air with sound waves. Molecules of matter have both wave and particle properties, and these particles (or wavelets if you wish to call them that) simply exert their pressure by momentum transfer when they make a collision. Remember light also has wave and particle behaviour; a quanta of light (which is also a little wavelet) exerts pressure by momentum transfer in a collision, as with a gamma ray colliting with an electron and making the electron move. (This is the Compton Effect). Radiation pressure is really the momentum transfer from collisions with wavelets! I hope this is clear to you. R. Bersin..
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