MOON AND THE EARTH

Otago Daily Times, Issue 22566, 9 May 1935, Page 11

MOON AND THE EARTH

RESEARCH IN AMERICA The gravitational pull of the tuoon apparently creates tides in the solid earth which change the distance between North America and Europe as much as (33ft, according to Dr Harlan T. Stetson, visiting professor at the Harvard Institute of Geographical Exploration, and Dr A. L. Lootnis, of the Loouiis Laboratory at Tuxedo Park, states the New York Times.

The effect of such an earth tide larger than could have been expected was detected when Dr Stetson and Dr Loomis found that discrepancies in astronomically checked clocks in Europe and in North America increased and decreased regularly with changes in the moon's position. Clocks are checked astronomically by comparison with the movement of stars across the meridian, a semi-circle running through north and south and a point directly over the observer's head. If discrepancies are found in two clocks, thus checked by the stars, then the position of either one or the other of the stations appears to have moved east or west, thus changing the observer's meridian. The scientists discovered that the discrepancies between American and European clocks, at astronomical stations where the checking was done regularly, moved either east or west of their normal positions. When the position of the moon caused both stations to move apart, the average distance between them might be iucreased by about 32ft, they found. If the moon caused them to move toward each other, they might be nearer together by the same amount. United States time signals checked at Washington are broadcast from the uaval station at Annapolis. English tinn signals, checked at Greenwich, are broadcast from Rugby, and French time signals, checked at Paris, are broadcast from Bordeaux. At specified times, each station picks up the signals of the other two.

Discrepancies noted between Annapolis time signals and those from Rugby were seen to rise and fall with the moon's position. Almost exactly the same curves of rise and fall appliad to the transmission between Annapolis and Bordeaux. But between Rugby and Bordeaux no such relationship was seen. Evidently something takes place over the Atlantic which does not take place between England and France.