Rutherford’s Atom: 1897–1945

“If your experiment needs statistics, you ought to have done a better experiment,” said Ernest Rutherford. There was no single revolution, but atomic theory went through a series of paradigm shifts in the 20th century. Originally from New Zealand, known for believing that swearing at experiments made them work better, Rutherford was the person who started the ball rolling when he discovered that the atom has a dense nucleus, separate from its orbiting electrons. He followed this by discovering the proton; and then James Chadwick in his laboratory discovered the neutron. The first revolution in atomic structure revealed the atom as consisting of three discrete particles: protons and neutrons in the nucleus, with the much smaller electrons circling the nucleus. The atom was mostly empty space. This was the prequel to the discovery that the atom is a matter of statistics and probability rather than discrete particles.