From the May 18, 1929 issue
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One of England's most expert aerial photographers, Capt. Alfred G. Buckham, F.R.P.S., contributes the cover picture for this week in the form of the first aerial photograph of a sandstorm, known in Egypt as the "terror of the desert." The Great Pyramid of Cheops is in the foreground.
TEN VACUUM MILE BEAM FOR LIGHT CHECK
Reflecting a beam of light back and forth 10 times through a pipe a mile long, from which the air has been exhausted, is the experiment soon to be undertaken by Prof. A.A. Michelson, famous physicist of the University of Chicago. Professor Michelson is now in Pasadena, California, where the experiment will be performed in order to check more closely the speed of light.
His interest in the speed of light began 46 years ago, while he was an instructor at the U.S. Naval Academy at Annapolis. Two years ago, he completed a series of experiments along the same line which involved sending a beam of light from Mt. Wilson to a neighboring peak and back. These experiments showed that light travels 186,284 miles every second and gave the most accurate figure for it that has ever been obtained.
But Prof. Michelson is still not entirely satisfied. In a second, a beam of light might travel as much as a quarter of a mile more or less than 186,284 miles. Close as this is, he thinks that he can get it still closer, and so he will not be satisfied until he has done so.
RADIUM EFFECTS NOT DUE TO COSMIC RAYS
Whatever it is that makes radium and related elements disintegrate and give off the rays that are so helpful both to the physicist and the physician, the cosmic rays are not responsible. This has been found by Dr. Louis B. Maxwell, National Research fellow working at the Bartol Laboratory of the Franklin Institute. He will report his latest researches in the forthcoming issue of the institute's journal.
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