|The dominant frequency of the radiation
emitted from a Black Body depends on its temperature.
At the end of the 19th century
most scientists thought that classical physics (built upon
Newton's mechanics and Maxwell's electromagnetism) reigned
supreme and could explain all aspects of matter and radiation.
There appeared to be just a few things which needed to be
fully understood. One of these was the nature of the electromagnetic
radiation emitted from a so-called 'Black Body'. This work
provided a crucial first step away from classical physics.
A Black Body is an object which continually absorbs and
re-emits all the electromagnetic radiation falling onto
it. A large effort was expended on measuring, and then
trying to explain the spectrum of frequencies in the radiation
emitted from a Black Body. The dominant frequency depended
on the temperature of the Black Body but no one could
find a single theory to describe the entire frequency
spectrum. Theories based on existing classical ideas predicted
an ever increasing intensity of radiation as the frequency
of the radiation increased towards the ultraviolet domain.
This was popularly dubbed the 'ultraviolet catastrophe'.
Clearly, these theoretical predictions had to be wrong,
otherwise the people studying Black Bodies would have
been severely injured by the high intensity of radiation!