- #1
kelly0303
- 579
- 33
Hello! In the descriptions of the BB radiation that I read, I see that we assume we have a cavity at a fixed temperature in equilibrium, we make a hole in it and we look at the intensity of different frequencies emitted through that hole. As far as I understand, the intensity dependence on the frequency (and temperature) doesn't depend on the shape of the cavity. I am not sure I understand why. For a given shape of the cavity, certain frequencies are not allowed (for example for a box, only wavelength that are a divisor of the length of the box work). So how can we talk about the intensity at a given frequency (and temperature), if that frequency is not allowed at all in the cavity? Shouldn't it be zero? And doesn't this mean that the shape of the cavity matters? What am i missing? Thank you!