Science: Ray Circus

The quest for the cosmic ray was a four-ring circus last week.

The main purpose of Belgian Professor Auguste Piccard’s stratosphere balloon flight (see p. 32) was to record the effect of cosmic rays at high altitudes. At his ceiling of almost eleven miles the rays “were like rain on a tin roof.” The professor is a mild hyperbolist. To cosmic rays the wide-spaced atoms of his aluminum gondola were less hindrance than a chicken-wire fence to bird shot.

Next year Professor Piccard hopes that some U. S. or Canadian physicist will “take off from the Northwest shore of Hudson Bay, as close as we can get to the North Magnetic Pole. Our purpose will be to complete the study of cosmic rays at a point where the lines of magnetic force penetrate the stratosphere.” The North Magnetic Pole is a point on the Boothia Peninsula of Canada’s Northwest Territories, close to where the 96th-meridian of west longitude crosses the 71st parallel of north latitude. It is 1,311 statute miles from the North Pole, about 800 miles due north from Churchill on Hudson Bay. Travellers can get to Churchill by grain freighter directly from England. With special Governmental permission they may travel by railroad via The Pas, Manitoba.

Racing up toward Churchill last week was Professor Arthur Holly Compton of the University of Chicago. The week prior he had been atop the Nevada de Toluca near Mexico City. Mrs. Compton and their son Alan were with him.

As soon as he made his readings of cosmic rays above Mexico, he dashed for a north-bound train. At Kansas City he said good-by to Mrs. Compton and Alan. They proceded to Chicago & home, he to Winnipeg. He wants to get to Chesterfield Inlet north of Churchill in time to note what the solar eclipse does to cosmic rays near the North Magnetic Pole. In his dash Professor Compton hastened past the U. S. Aerological Station at Ellendale, N. D. Thereby he just missed conjunction with his fellow Nobel Laureate, Dr. Robert Andrews Millikan of California Institute of Technology. Dr. Millikan was heading for Ellendale to fly around with Station Director Thomas Lawlor this week. They are to take aloft a self-recording electroscope whose invention Dr. Millikan announced from Pasadena last week. It is ten times as sensitive to cosmic rays as any other electroscope he knows of. Vibration does not disturb it. Hence unlearned Army fliers are to take up replicas to heights of from 20,000 to 25,000 ft. Co-inventors of the new Millikan electroscope were Professors Ira Sprague Bowen. and Henry Victor Neher who works under Dr. Millikan at Caltech. The highest Dr. Millikan has sent an electroscope was in a free balloon to 9.6 miles, a height surpassed by Professor Piccard last year, and again last week. Last fortnight Professor Erich Regener of the Institute of Technology at Stuttgart despatched a free balloon from Stuttgart. Attached were a self-recording altimeter and electroscope. The balloon returned to earth, close to home. It had risen to 92.000 ft., nearly 17½ mi., about 7 mi. higher than Professor Piccard’s. Professor Regener’s automatic electroscope readings disagreed with those which Professor Piccard reported last year. (Last week Professor Piccard had no time to interpret his new readings.) Professor Piccard then said that the intensity of cosmic rays increased steadily up to ten miles. Professor Regener found that the intensity increased steadily up to 39,000 ft. (72-mi.) beyond which the rate of increase slowed up until 85,000 ft. (16 mi.) was reached. After 85,000 ft. and up to the ceiling of 92,000 ft. the field of cosmic rays was steady. If this apparent Regener-Piccard discrepancy disappears after study of the new Piccard data, then no longer need he risk life and comfort. Free balloons will serve to carry electroscopes aloft. The uniform cosmic ray field above 85.000 ft. indicates—if Professor Regener’s record is accurate—only that Earth’s lower atmosphere impedes the cosmic rays of their arrival from some source off Earth. It does not show what that source is—whether the rays originate from the destruction of matter in the stars (Jeans theory) or from creation of matter in the void between stars (Millikan theory). Certain aspects of cosmic rays suggest that they may be the newly recognized neutrons. Or they may be electrons drifting down from the heavily ionized, pulsating casing called the Kennelly-Heaviside Layer which at a distance of 100 mi. or so encloses Earth as a shell encloses its yolk. Against that yielding, yet fluctuating casing radio waves rebound and in it flutter the curtains of the Northern Lights.