"The Creator is still on the job." California's great Robert Andrews Millikan has said that so often that it has become a slogan, epitomizing his personal philosophy as well as his scientific theories. Cosmic rays, he has time & again told the world, are born of the creation of matter in interstellar space. Last week in London, before most of the world's greatest physicists, Dr. Millikan was ready to admit, and did admit, that cosmic rays seem to be offspring of destruction as well as of creation.
Physicists have not been content to pursue the cosmic ray in laboratories. They have carried their ionization chambers to mountain peaks, installed them on round-the-world ships, sunk them to the bottom of deep lakes, taken them down in mines, flown them in airplanes, sent them up in balloons manned and unmanned. All over the world, from Panama to Ceylon, from the Equator to within 350 miles of the North Magnetic Pole, they have carried a cosmic quest which has cost at least two lives. It has been found that cosmic rays are either particles of matter or units of radiation, or both, with energies of billions of electron volts, energies beyond the power of any man-made device to reproduce. They bombard Earth continually from all directions. The most powerful can penetrate 3,200 ft. of water or 290 ft. of lead. Estimate: 30 cosmic rays pass through every human body every second. And it is suggested that cosmic rays cause old age, death.
Dr. Millikan was sure the rays were electrically neutral photons or light bullets. The University of Chicago's beetle-browed Arthur Holly Compton was equally certain they were electrically charged corpuscles. Dr. Compton's stand was strengthened by the piling up of evidence that cosmic ray intensity is less near the Equator than in high latitudes. That seemed to show that the rays were charged particles attracted to the Poles as a compass needle is. Then it was found that more cosmic rays come from the west than from the east. That datum, considered with reference to Earth's magnetic field, made it appear that most of the rays were positively charged protons or positrons.
Dr. Millikan rejoined that these corpuscles were very likely atmospheric ions, secondary products of the primary photons. Once on the verge of heated dispute (TIME, Jan. 9, 1933), the two savants re-established cordial relations by agreeing that the primary radiation might well be mixedeach retaining his own view of the proportion of mixture.
But there has also been a cosmic disturbance between Dr. Millikan and Sir James Hopwood Jeans, who thought the rays were by-products of the steady annihilation of star substance. To pious Dr. Millikan the notion of a universe crumbling to chaos was repugnant. But to honest Dr. Millikan a fact is a fact. The fact that moved him to change his mind, he admitted last week, was the high energy of some cosmic rays. Low energy rays might still be deemed to arise from the building of elements. But when rays of 10,000,000,000 volts are detected on the Equator, the only conceivable source of such energy is the conversion of matter into radiation. And to Dr. Millikan last week "conversion" seemed inescapably synonymous with outright destruction.