Word: dirac
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Every time an honored theory is disproved or amended, science makes a little progress. For 20 years the Dirac theory of electron behavior has been the bible of wave (quantum) mechanics.* Last week Columbia University announced that two of its young scientists, Professor Willis Lamb, 34, and Robert Retherford, 35, had knocked a prop from under the Dirac theory. Their experiment, said Columbia's Nobel Physicist Isidor Isaac Rabi, revealed new facts which will be of "inestimable value in future research...
...Dirac theory predicts, among many other things, that hydrogen atoms can exist in two different "states"-one stable, the other unstable-which contain the same amount of energy. Lamb & Retherford checked up with ultrashort radio waves (war-developed for radar), and found that this prediction was not correct...
...their frequency is enormously smaller, they carry much less energy per "photon."* They therefore provide what scientists call an "elegant" method of dealing out very small quantities of energy. Using a formidable-looking gadget, Lamb & Retherford shot radar waves of the proper frequency through hydrogen atoms in one of Dirac's predicted states. As soon as the energy was added, the atoms turned into the other state. Since energy was required to make the change, the experiment showed that the two states did not have the same energy originally. Therefore, Dirac's theory was proved incomplete...
...Dirac is the genius who sensed the existence of the positron (positive electron) by figuring how a "hole" would behave if one should appear in a field of (negative) electrons. The hole, he decided, would act like a positive electron. Though no such particle had ever been found, colleagues began to look. Sure enough, they found the holes, as tangible as anything in basic physics, and named them "positrons...
...Princeton, 15 years later, Dr. Dirac, who had forecast a particle, theorized about what happens when one particle strikes another. He selected the two simplest: the electron and the photon (unit of electromagnetic radiation, such as light). To explain how they interact, he ploughed through relativistic bafflements, covered a blackboard with lacy mathematics. Many listeners looked as if they had been hit on the head. Dirac himself seemed unsure...