Tuesday, January 14, 2020

waves - Energy conservation in interference?


Does interference of light follows first law of thermodynamics?


If yes then where does light vanishes in minimum interference pattern?



Answer



Light doesn't "vanish" - it "finds another way".


When you have a thin bubble you see interference fringes in the reflection - when the bubble gets sufficiently thin, the reflection disappears completely. This means that the light was transmitted.


In general, if you have an interference pattern, for every minimum (fewer photons) there is a corresponding maximum (more photons) leaving the total energy unchanged.


The first law holds. If you can think of a situation where it does not, please describe it in more detail.


No comments:

Post a Comment

classical mechanics - Moment of a force about a given axis (Torque) - Scalar or vectorial?

I am studying Statics and saw that: The moment of a force about a given axis (or Torque) is defined by the equation: $M_X = (\vec r \times \...