Discrete vs Continuous Spectra in Blackbody Radiation?

[greswd]

I was reading this article which talks about the theoretical model behind blackbody spectra:
http://www.cv.nrao.edu/course/astr534/BlackBodyRad.html

At the start, it mentions standing waves in a cavity. Standing waves in this model consist of an integer number of wavelengths. The standing waves can only occur at specific, discrete wavelengths.

Therefore, could a blackbody emit in a discrete spectrum under certain conditions?

 

[greswd]

If you want to discuss Planck vs Rayleigh-Jeans, take note that Planck's difference only comes in at this section:

In thermodynamic equilibrium at temperature T, equipartition of energy implies that each mode has average energy <E>=kT according to the classical Boltzmann law (but not according to quantum mechanics).