It is very common to introduce quantum physics in an historical context. Though there are advantages
to this, it is a problem that many of the stories that have become central to the physics lore
are mere pseudo-histories far detached from the real events.

It is about time that we stop uncritically copying these stories and instead make an effort to present
the development of quantum physics as it actually was. This paper deals with one of the most
common myths in quantum history, the one about the ultraviolet catastrophe and how it motivated
Planck’s introduction of quantum physics.

On closer inspection it turns out this story has the time-line completely turned on its head. The
ultraviolet catastrophe was first discussed several years after Planck published his radiation law
so it played no role in his motivation. Instead Planck was concerned with finding a theoretical
derivation of the law for blackbody radiation. This law was first thought to be Wien’s radiation
law, but when new data disagreed, Planck came up with his own law that fitted the data.

Planck’s radiation law first came about as an elaborate fit to data and to derive it he found no other
way than to use statistical mechanics and divide the energy that was to be distributed on the atomic
oscillators into packages ℎ 𝑓 so that he could count the number of ways to distribute this energy.
Planck did not consider this a quantization, but merely a mathematical trick to be able to calculate
the entropy of the oscillators.