Freeman Dyson on Ernest Rutherford

“Rutherford's discovery was the beginning of the science that came to be called nuclear physics. ...The projectiles that he used to explore the nucleus were particles produced in the disintegration of radium... discovered by Marie Curie in 1898. The particles are helium nuclei that are emitted at high speed when radium atoms decay...The twenty years between 1909 and 1929 were the era of tabletop nuclear physics. ...Small and simple experiments were sufficient to establish the basic laws of nuclear physics.”

“The switch from natural sources of particles to accelerators would start a new era in the history of science, the era of accelerator physics. ...The two men who actually built the first accelerator were John Cockcroft and Ernest Walton, graduate students working... under the supervision of Rutherford. ...For five years they struggled to create a technology of big machines in a laboratory of tabletop experiments, just as the Wright brothers had struggled to create a technology of flying machines in a bicycle shop ....In April of 1932, they had a machine that produced a steady stream of hydrogen nuclei with an energy of about half a million volts. ...Walton was... ready to do the experiment... to bombard a target made of the light metal lithium. The result was spectacular. The lithium nuclei were split in two and fell apart into pairs of helium nuclei. The helium nuclei came out with thirty times as much energy as the hydrogen nuclei going in. ...Rutherford happily spent the rest of the day serving as Walton's assistant... That day, the era of tabletop nuclear physics ended and the era of big machines and big projects began.”

“He died a year before the discovery of the fission of the uranium nucleus in Berlin in 1938, the discovery which turned nuclear physics into a big industry and a weapon of war.”

“Rutherford did not pretend to understand quantum mechanics, but he understood that the Gamow formula would give his accelerator a crucial advantage. Even particles accelerated at much lower energies... would be able to penetrate into nuclei. Rutherford invited Gamow to Cambridge in January 1929... [They] became firm friends and Gamow's insight gave Rutherford the impetus to go full steam ahead with the building of his accelerator.”