Physics & Fantasy

Physicists look and act like ordinary men, but when they get together, many of the things they talk about approach the frontier of fantasy. Last week the American Physical Society, in convention in Manhattan, heard plenty of frontier talk. A few of the high-level matters discussed:

Deep-Frozen Amplifier. Some theoretical physicists have no visible connection with practicality, but others who are just as erudite hope that "hardware" will eventually grow out of their bold thinking. Professor Malcolm W. Strandberg of M.I.T. bases his reasoning on the weird idea of temperatures below absolute zero. Such temperatures do not exist in the ordinary, tangible sense, but they help Dr. Strandberg think about phenomena strongly affected by temperature.

One of these is the amplification of radio messages. If an ordinary amplifier is set for too great a gain, all it does is magnify the random noise caused by the thermal motions of atoms and electrons. At the extremely low temperature of liquid helium, thermal motions almost stop, so Dr. Strandberg figured that an amplifier that would work at such temperature might be efficient beyond dreams.

Theoretical studies told him that a speck of the proper kind of crystal, held in a magnetic field at a temperature close to absolute zero, should work as an almost noiseless amplifier. Naming the unborn device the Versitron, Dr. Strandberg predicted extraordinary powers for it. In electronic communication, the power of the transmitter might be cut to one-thousandth. The telescopes of radio astronomy might become so sensitive that astronomers would have to spend years digesting the records of a short observing period. No Versitron has been built, but Bell Telephone Laboratories, guided mainly by Dr. Strandberg's theories and those of Professor N. Bloembergen of Harvard, has tested successfully a deep-frozen device that acts as an oscillator and promises to grow into a Versitron-like amplifier. Magnetic Explosion. The magnetic fields that exist around horseshoe magnets are gentle, harmless things, but when a magnetic field gets really intense, it acts like a high explosive. Physicists H. P. Furth of the University of California, M. A. Levine of the Air Force Cambridge Research Center, and R. W. Waniek of Harvard showed a ring of hard beryllium copper that had been expanded plastically by a magnetic field, even though it was surrounded by steel many inches thick.

Working together at Harvard, the three scientists shot an enormous current for a few millionths of a second through their copper ring. Inside the ring the magnetism jumped to the unheard-of level of 1,600,000 gauss.* Pressure rose above 1,000,000 lbs. per sq. in., and the metal churned and writhed as the magnetism clawed into it. Such pressure and violent motion may have some bearing on nuclear fusion, and this may be why Furth is now working at the famous hydrogen-bomb laboratory at Livermore, Calif.

A single magnetic explosion, which makes a bang like a big gun, destroys costly apparatus, so Furth, Levine and Waniek are trying to design a super-magnet that will not destroy itself. The basic idea is to oppose one magnetic force by another magnetic force instead of by the passive strength of metal. Theoretically this can be done by elaborately wound coils, or by copper sheets intersecting in intricate ways. The theory looks so good that the three scientists are promising to deliver many million gauss of magnetic field, and to churn matter in ways that it has never been churned before. One possibility: a magnetic gun that can shoot a small pellet at 100,000 ft. per second. This is nearly three times the speed needed to shoot it wholly free of the earth's gravitation.

Head-On Accelerator. Another team of dealers in magnetic fields. Dr. Lawrence W. Jones of the University of Michigan and Tihiro Ohkawa of Tokyo University, told their colleagues about a new and cataclysmic kind of atom smasher. The most powerful one in operation at present is the Bevatron at Berkeley (6 billion electron volts), and a 25-Bev monster is under construction at Brookhaven National Laboratory on Long Island. These are rather puny little gadgets, think Jones and Ohkawa. The way to get real power is to force head-on collisions between high-speed particles.

Simplest way to do this would be to build two conventional accelerators and make their particles collide, but all the machines known today shoot out so few particles that collisions between them would be too rare. Dr. Jones described a special accelerator that yields a beam so dense that it should cause many collisions with another beam. Better yet is Ohkawa's idea: an accelerator with two streams of particles circulating in opposite directions in the same circular path. Guided in a chainlike pattern by magnetic fields of alternating direction, the streams will cross each other many times as they go round the circle, and their particles will experience many magnificent crackups at each intersection.

Head-on collisions between particles, say Jones and Ohkawa, will begin a new epoch in physics. The rules that govern such matters are complicated by relativity, but generally speaking, two particles that collide with energies of 15 billion electron volts each will have the smashing effect of a single particle with 540 billion electron volts. Such enormous energy is found only in rare cosmic rays, which can be studied undisturbed only at the inaccessible top of the atmosphere. If goodly numbers of these collisions can be caused in the laboratory, where they can be observed accurately, a new and horrendous kind of physics should be the result.

*A unit of magnetism. The earth's magnetic field is approximately .3 of one gauss at New York City.

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