Ernest O. Lawrence

1939 - For his invention and development of the cyclotron

The cyclotron was the first circular-shaped particle accelerator or “atom-smasher.” This circular design made possible the acceleration of particles to unprecedented energies before being smashed, thereby opening the door to modern experimental physics.

Edwin M. McMillan

1951 - (With Glenn Seaborg) for their discoveries in the chemistry of the transuranium elements

In 1879, uranium, element 92, named after the planet Uranus, had been declared the upper limit of the periodic table. Sifting through the debris of nuclear fission, McMillan and Philip H. Abelson found element 93 in 1940 and named it neptunium after the next planet, Neptune. Their discoveries proved that elements existed beyond uranium on the periodic table.

Owen Chamberlain

1959 - (With Emilio Segrè) for their discovery of the antiproton

In 1952, using the Bevatron accelator and an elaborate network of detectors, Chamberlain, Segré, and colleagues Clyde Wiegand and Thomas Ypsilantis smashed atoms of copper with highly energized protons. This brought into fleeting existance the negatively-charged protons that confirmed antimatter theories.

Emilio Segrè

1959 - (With Owen Chamberlain) for their discovery of the antiproton

The existance of antimatter or “mirror matter” was theorized in 1930. Two years later, the positron, an electron with a positive charge was found, but until a proton with a negative charge could be identified, antimatter could not be confirmed. Segrè was an expert on nuclear forces and the discoverer of technetium, the first artificially-produced chemical element.

Donald A. Glaser

1960 - For his invention of the bubble chamber

Bubble chambers gave scientists their first means of studying the swarm of fast-moving, short-lived nuclear particles that emerge from accelerator collisions. Sending such particles through a chamber filled with superheated liquid leaves signature “tracks” of bubbles that can be photographed and analyzed.

Charles H. Townes

1964 - For inventing the maser and concepts that led to the creation of the laser

An acronym for “microwave amplification by stimulated emission of radiation.” Using a weak microwave beam, a maser produces “a cascade of transitions in ammonia molecules,” which reinforces the beam. It was the forerunner of the laser, “light amplification by stimulated emission of radiation.” These devices spawned a new industry and advances in medical treatment.

Luis W. Alvarez

1968 - For his decisive contributions to
elementary particle physics

Alvarez’s identification of resonance state—ephemeral states of matter that flare up within the nuclei of atoms—unleashed a stampede of sub-atomic particle findings and laid the groundwork for the discovery of quarks.