Poetry of Physics and the Physics of Poetry

170 The Poetry of Physics and The Physics of Poetry

the cavity. Any light, which does enter the cavity, is quickly absorbed by
the inner walls. The distribution of energy of the thermal radiation can be
studied by observing the radiation emerging from the hole in the shell.
The results of this study are shown in Fig. 18.2 where the intensity of
radiation is plotted versus the frequency for two different temperatures.
The total amount of energy radiated increases rapidly with the
temperature. It is proportional to the fourth power of the temperature. (If
E is the total energy, T, the temperature, and k, a constant, then E = kT^4 ).
As the temperature increases, the distribution shifts to the higher
frequencies. The frequency for which the intensity is a maximum is
proportional to the temperature.

162 The Poetry of Physics and The Physics of Poetry

the thermal emission of electromagnetic radiation from the inner walls of

the cavity. Any light, which does enter the cavity, is quickly absorbed by

the inner walls. The distribution of energy of the thermal radiation can be

studied by observing the radiation emerging from the hole in the shell.

The results of this study are shown in Fig. 18.2 where the intensity of

radiation is plotted versus the frequency for two different temperatures.

The total amount of energy radiated increases rapidly with the

temperature. It is proportional to the fourth power of the temperature. (If

E is the total energy, T, the temperature, and k, a constant, then E = kT^4 ).

As the temperature increases, the distribution shifts to the higher

frequencies. The frequency for which the intensity is a maximum is

proportional to the temperature.

Fig. 18.2

The experimentally observed energy distribution represented by the

solid curve differed very radically from the theoretical prediction

depicted by the dashed curve in Fig. 18.2. It was believed that the higher

frequencies would dominate the distribution since the probability of

exciting a frequency was thought to be greater, the higher the frequency.

This prediction was not fulfilled, however, and the intensity, instead of

steadily increasing with frequency, reached a maximum value and then

Fig. 18.2

The experimentally observed energy distribution represented by the
solid curve differed very radically from the theoretical prediction
depicted by the dashed curve in Fig. 18.2. It was believed that the higher
frequencies would dominate the distribution since the probability of
exciting a frequency was thought to be greater, the higher the frequency.
This prediction was not fulfilled, however, and the intensity, instead of
steadily increasing with frequency, reached a maximum value and then
decreased to zero. This result was a total mystery to the physicists of the