Let us place our ideal solid, [S.sub.1], in an imaginary box.
Thus, an ideal solid containing no heat energy is close to absolute zero as defined by the 3rd law of thermodynamics.
For our ideal solid, thermal equilibrium can only be achieved through thermal conduction which in turn is supported by energy contained in the vibrational degrees of freedom.
In our ideal solid, the vibrations of the atoms are the underlying support for this process.
For an ideal solid, the light emitted in an attempt to reach or maintain thermal equilibrium will contain a continuous range of frequencies (see Figure 4).
Planck's equation states that the light produced, at a frequency [upsilon], by a blackbody (or an ideal solid), [B.sub.[upsilon]], depends only on two variables: temperature, T, and the frequency, [upsilon].
As mentioned above, an ideal solid is a blackbody, or a perfect absorber of light ([[kappa].sub.[upsilon]] = 1).
The next available means of dealing with heat lies in breaking bonds that link up the atoms forming the ideal solid. As these bonds begin to break, the atoms (or the molecules) gain the ability to change their average location.
Graphite, perhaps the closest material to an ideal solid, sublimes (see Figure 6) and never melts.
