The Structure of the Atom 167
10 -8 cm. Most of the atom therefore consists of empty space. This was
the only picture of the atom consistent with the result of Rutherford’s
experiment.
This picture of the atom presented a rather grave problem, however.
According to the classical theory of electromagnetic theory, any particle
accelerating will radiate light energy. Since the electron orbiting the
nucleus is continually accelerating, it should also be continually radiating
light and hence, losing energy. As it loses energy, it spirals into the
nucleus until it is finally absorbed. Essentially, the miniature solar
system atom is unstable from the point of view of classical
electromagnetic theory. The solution of this problem, which Bohr
proposed two years later in 1913, is related to the quantization of the
energy of light discovered earlier through the work of Max Planck in
1900 and Albert Einstein in 1905. Before continuing with our story of
the atom, we turn our attention to the discovery of the photon and the
quantization of energy.