Planck assuming that the walls
of the Black Body could be covered in electric oscillators.
The hotter the temperature, the more the oscillators
The father of quantum physics,
Max Planck, was based in Berlin and was known to be an extremely
conservative and passionate advocate of thermodynamics – the
classical theory describing the transformation of energy.
Despite this background, Planck took the bold and innovative
step of assuming that the walls of the Black Body could
be covered in electric oscillators. Remember, nothing was
known about atoms at this time. The oscillators vibrate
more and more as the temperature of the Black Body increases.
It was good that Planck was a thermodynamicist! Electromagnetic
theory could explain the emission, absorption and propagation
of radiation from the oscillators, but it had nothing
to say about how the energy was distributed between the
oscillators – only thermodynamics could answer this.
Borrowing ideas from thermodynamics, Planck managed to
derive an equation which perfectly described the Black
Body frequency spectrum.