IS EINSTEIN WRONG?

Greymouth Evening Star, 30 August 1932, Page 2

IS EINSTEIN WRONG?

DEFLECTION DISCUSSION. When Albert Einstein propounded in 1916 his revolutionary views concerning the nature of matter, space, and gravitation, he gave three tests of an astronomical character by means of which his theory might »be tested. Of these the best known and most easily comprehensible is that which requires that rays of light, passing in cosmic space near to any celestial body, will,, in virtue of that body’s gravitational influence, be bent out of their straight course in a manner similar to that experienced by a material body, such as a comet, passing near the sun. The computed amount qf this deviation, mainly because of the great speed with which light travels, is. very small indeed, so that of all the bodies in our solai- system the

sun is the only one competent to produce an effect large enough to be measurable —the change of direction to a ray grazing the sun’s limb is about the same as the angle between two lines drawn to the ends of the diameter of a half-penny three and a-half miles distant —and this is observable only during those rare and brief occasions when the sun’s disc is totally eclipsed by the moon, says a writer in the Melbourne “Age.”' Four separate eclipse expeditions since 1916 have made it their chief aim to test the truth or untruth of this prediction. The first observations and made in 1919 by British astronomical .expeditions under the leadership of Sir Frank Dyson and ’Professbi' (Sir Arthur) Eddington, gave results, which, though showing considerable differences for the different stars, on the whole tended.

very definitely to support Einstein’s theory. Nevertheless, it was felt that confirmation was desirable, and in 1922 a well-equipped party of American observers, led by Professor Wallace Campbell, of the Lick Observatory, came.to Australia and set up an observing station at Wallal, in northwest Australia. Excellent photographs were obtained, and the measurement and reduction of these again gave results in accordance with Einstein’s theory. , Two plates secured at Cordillo Downs by the South Australian eclipse expedition on the same occasion were

sent to Greenwich Observatory for measurement. These, too, gave confirmatory results, and the majority of astronomers and interested scientific men generally regarded the “Einstein deflection” as a proven verity—all the more since the two other astronomical consequences of his theory predicted by Einstein had also given evidence highly favourable to its truth. . In 1929 a German party, led by Einstein’s personal friend and fellowworker in astronomy, Professor Freundlich, provided with the best equipment which German workshops .could supply, and employing an elaborate procedure designed to eliminate or control every possible source of error, made fresh observations on the track of the total eclipse in Sumatra. The results of their measurements and calculations, announced by Professor Freundlich at a meeting of the Royal Astronomical Society in London last December, and now published and discussed in German scientific journals, are decidedly disturbing to devout believers in the new revelation. They do, indeed, reveal a deflection of the light rays in the sense expected, but the amount of this deflection, on the average, exceeds by 30 per cent, the value which the theory requires. Worse still, a recomputation by the German scientists of the Lick Observatory measurements, using a procedure which they claim to be free from

certain vitiating assumptions involved in that used by Drs. Campbell and Trumpler, gives a value closely agreeing with their own. There is, of course, the possibility that all these measurements are affected by some unknown, systematic error, which, when discovered and allowed for, would reduce the value of the deflection found to that demanded by the relativity theory. This, at least, will be the hope of all who find satisfaction and conviction in the logical completeness and consistency of the Einsteinian system of natural philosophy, and who would feel a sense of tragedy should so beautiful a theory be condemned to suffer death on the evidence of on awkward little fact.