Narrator: ``So the theorists are working on it, and surely with a little more mathematical sophistication all these temporary fixits will reveal their sensible character. Sadly, the experimentalists are at it again too, and are generating more embarrassing problems. In a quaint backwater town of the snowy Canadian wilderness, Ernest Rutherford is visiting McGill University and tinkering with Marie Curie's alpha rays.''
Rutherford: ``It's amazing how many of these heavy elements decompose spontaneously, giving off alpha particles, which I have discovered are actually the nuclei of helium atoms.''
``I believe I'll move back to England to do some more experiments with these things.''
[Walks across stage to signify this.]
``Here in Manchester I tried scattering alphas off a thin gold foil.
[Uses chalk in demo of scattering.]
`Most of the time we see just what you'd expect: the alphas shoot right through the foil and out the other side, with only a little deflection. But occasionally - very rarely - one will bounce straight back from the foil. It is like firing shells at a piece of paper handkerchief and having them bounce back at you.
``The only way this could possibly happen is if most of the mass of the atom is contained in a small, hard, positively charged NUCLEUS about which the electrons orbit like planets about the sun!''
Born: [jumping up and down, ears steaming, foaming at the mouth]
``That's insanity! Orbiting electrons are accelerating and thus radiate away their energy!''
Grabs chalk, draws spiraling orbit; classical calculations show electron falls into nucleus in ns.
Bohr:
[takes chalk to blackboard]
`` . . . so we're forced to postulate discrete orbits
and energy levels in atoms.''
[Connects all three problems by quantization of angular momentum, thus also emitted and absorbed energy.]