Science: Nobelmen of 1958

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Even as all Moscow reverberated with the volleys of invective loosed upon Boris Pasternak (see FOREIGN NEWS), the Nobel Prize committee announced that the prize in physics had been awarded to Russian Physicists Pavel A. Cherenkov, Igor I. Tamm and Ilya M. Frank. Without a trace of embarrassment over its inconsistency, Soviet officialdom beamed, and nobody charged (as they had with Pasternak) that it would amount to accepting a "handout" from "the enemy." All three Russians rank high in the esteem of,the outside world as well as in the Soviet scientific hierarchy. Dr. Tamm is often rated as the leading Soviet nuclear physicist, represented Russia at the recent Geneva conference on technical means for detecting atomic explosions.

The research that led to the award began in 1934, when Cherenkov. then 30, noticed a bluish glow where gamma rays from radium were striking through water in a flask. The glow was exceedingly faint, and a less curious man might have put it aside as ordinary fluorescence, which is given off by many materials when struck by gamma rays. But Cherenkov's mysterious light proved to be strongly polarized, had a continuous (rainbow-like) spectrum, and was given off predominantly in the direction of the gamma rays.

The Cherenkov radiation remained a tantalizing mystery until three years later. Two other Soviet physicists, Ilya M. Frank and his senior, Igor Tamm (who studied at Edinburgh and speaks English with a Scottish burr), became interested, worked out a strange but correct theory. When gamma rays pass through water, they hit electrons, and the impact bumps the electrons up to high velocities. The electrons do not move faster than light in a vacuum (186,000 m.p.sec., the Einsteinian speed limit of the universe), but they do move faster than light in water, 140,000 m.p.sec. For exceeding the local speed limit, the electrons are "fined" a part of their energy, which shows up as Cherenkov radiation. Something analogous happens when a ship moves on the sea's surface. If the ship's speed exceeds that of the waves, as it usually does, some of the ship's energy appears as a bow wave that resembles the light waves observed by Cherenkov.

This led to the development of an extremely important modern instrument: the Cherenkov counter. It is made of some transparent substance such as Lucite. When a proton, electron or other charged particle enters it at a speed that is greater than the speed of light in the material, Cherenkov radiation is given off. Its angle (like the angle of a ship's bow wave) depends on the speed of the particle. When the angle is measured by a photomultiplier tube, the speed of the particles can be determined.

Cherenkov counters are now among the leading tools of physics. They fly high in rockets and Sputniks to measure the energy of cosmic rays. They keep watch in cyclotron laboratories. The Russians are now building a monster Cherenkov counter two stories high.

Bacteria and Flies. The award in medicine went to three U.S. scientists working in genetics—a field that had not even been named when Dynamite Maker Alfred Nobel died in 1896.

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