To test the hypothesis, Anderson placed a lead plate in the chamber. The resulting photographs surprised Anderson by revealing that cosmic rays produced showers of both positively and negatively charged particles, and the positive charges could not be protons, as one might expect, because the track radius would specify a proton stopping distance much shorter than the length of the track.Īnderson and Millikan speculated that perhaps the positively charged particles were electrons traveling in the opposite direction. By measuring the curvature of those tracks, he could calculate the particles' momentum and determine the sign of the charge. He surrounded his chamber with a large electromagnet, which caused the paths of ionizing particles to bend into circular paths. And he obtained much better photographs than his colleagues.
He also used a mixture of water and alcohol in the chamber. By measuring the density of the droplets, scientists can deduce how much ionization is produced-indicating the kind of particle that passed through.Īnderson built his own, improved version of a cloud chamber, incorporating a piston so that he could get the pressure to drop very rapidly. If an ionizing particle passes through the chamber, it leaves a trail of water droplets, which can be photographed. Most scientists were doing this by using cloud chambers: a short cylinder with glass end plates containing a gas saturated with water vapor. Millikan, Anderson turned his attention to studying those high energy particles. His early research was on X-rays, but then Victor Hess discovered cosmic rays in 1930. He ultimately went on to earn a PhD in physics engineering (now known as applied physics) from Caltech.Īnderson spent most of his career at Caltech. He originally intended to study electrical engineering but switched to physics after taking a particularly inspiring class in the subject.
Anderson helped support the family at a very young age, but still managed to get a college education at Caltech. When he was 7, the family relocated to Los Angeles, and his parents divorced shortly thereafter. Anderson would win the race.Īnderson was born in 1905 to Swiss parents in New York City.
ANTIMATTER PARTICLE VERIFICATION
The hunt was on to find experimental verification of this hypothesis a Caltech postdoc named Carl D. In 1928, British physicist Paul Dirac showed that Einstein's relativity implied that every particle in the universe has a corresponding antiparticle, each with the same mass as its twin, but with the opposite electrical charge. One of those is the matter/antimatter engines that power the Enterprise, enabling it to supposedly travel at speeds faster than the speed of light.
ANTIMATTER PARTICLE SERIES
Star Trek creator Gene Roddenberry incorporated a lot of actual science into what has become one of the most successful series franchises of all time. The particle enters from the bottom, strikes the lead plate in the middle and loses energy as can be seen from the greater curvature of the upper part of the track. Anderson, Physical Review Vol.43, p491 (1933)Īnderson's cloud chamber picture of cosmic radiation from 1932 showing for the first time the existence of the anti-electron.
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