Seward daily gateway., 1925-02-20
Why There Are Zones
 of Silence In the Air

During the great war it was observ- ed that there were mysterious zones of silence in which the reports of the heaviest artillery could not be heard.
 During the bombardment of Ant werp, for example, the boom of the big guns was heard sixty miles away. Beyond that for thirty miles it was not heard, and then farther still it was heard again. There were other in- stances where cannonading such as the world had never known was heard very far away, while at a nearer dis tance nothing could be heard In front of the church at Neuilly, sub- urb of Paris, in the calm of the night, the big guns at the front, 80 miles away, were heard distinctly while at Chantilly, twenty miles nearer the front, nothing was heard.
 Since the close of the war, scien- lists in France and England have been seeking to establish the cause of the strange phenomenon.
 Among these scientific investigators is Miller Christy, an English meteroI- ogist who has made an elaborate study of the audibility of Continental gunfire at Chignal, near Chelmsford, England. Among the results of his observation, reports the British Sci ence Guild News Service, was the fact that the direction of the wind had very little influence. If anything the fir ing was heard most plainly when the
 wind blew from a more or less west erly direction. A most interesting point however, in connection with the trans
 mission of the sound was that in every year apparently there was a regular
 and well-defined period during which
 the gunfire was audible at Chelmsford followed by long period during which !! it was seldom or never heard 1 There are numDer of theories as to why these zones of silence exist. l The first of these formulated was that by Won dam Borne, who based his ar
 gument on the hypothesis that at great heights the principal constitu- ent of the atmosphere was hydrogen, in which gas sound would travel much faster than in ordinary air. The pro- posaI has, however, certain difficult ties. It is not easy to see how a sound wave in hydrogen could force it's way back through the denser lay CTS of the atmosphere any more than it would be easy to see how a feather could have an appreciable influence on a ton of steel. Further, there is no evidence that upper layers of air con- sist of hydrogen.
 Fresh light was thrown on the problem by Lindemann of Oxford, in studying the death agony of particles cutting into the earth's atmosphere. Others had found by correlating obser- vations made of shooting stars at va rious distant points at what height in the atmosphere the death agony oc- cured. They worked on such data as that star bIazed for two seconds with luminosity as great as that of Venus. By calculating the distance travelled they were able to translate 1 the eneregy emitted into terms of horsepower, and determine the mass l of shooting star. They have come to | the conclusion that meteor as bright as Venus is in fact only as large as grain of sand. The effect, they con- tend, is not one of mere friction, but the air in front of the grain of sand becomes compressed and gets heated
 much as a bicycle pump does as re. suit of the air it is pumping being
 compressed. The particle then melts and incandesces."