Just a dump on what I know about Planck's hypothesis. Could you verify if my understanding is correct

@Arrowshaft?

Q: Describe how Planck's explanation of black body radiation changed the direction of scientific thinking in the early twentieth century. (3 marks)

Prior to Max Planck's hypothesis on the nature of black body radiation, the accepted model of light was Maxwell's continuous wave theory. However, Maxwell's theory was unable to account for the features of a black body curve. It predicted that vibrational modes of higher frequencies in cavity radiators were more likely than lower frequencies, which resulted in the predicted curve, according to Rayleigh-Jeans law, having no peak emission, and approaching infinite intensity at higher frequencies, violating the law of conservation of energy. This was known as the UV catastrophe. Physicists, such as Wien, attempted to account for the UV catastrophe through classical arguments, however essentially introduced arbitrary constants to fit a polynomial with no real underlying model.

Max Planck's hypothesis however had the extraordinary insight to approach the black body problem through a discrete, not continuous model. He modified Wien's law to remove the arbitrary constants and built a mathematical model with the underlying assumption that the atoms in the walls of a cavity radiator acted to transmit and receive only certain modes of oscillation based on their transitions between quantised thermal energy states. This resulted in the electromagnetic energy a black body could emit and receive being made up of discrete quanta E = hf.

Since most atoms in a black body would be at a given temperature, certain thermal energy transitions would be more likely than others, explaining the peak wavelength. The thermal energies required for atoms to undertake the large energy transitions required to release high frequency radiation were furthermore, very unlikely in the black bodies studied, explaining the UV catastrophe.

The immense success of Planck's quantised model in explained the black body curved hinted to physicists that there were shortcomings to the continuous, classical view of the world. Planck's hypothesis would go on to change the course of physics from the classical to the quantum, with his quantisation of electromagnetic energy being fully realised in Einstein's quantised photon model of light.