THE LAW OF GRAVITY.

Taranaki Daily News, 14 November 1919, Page 2

THE LAW OF GRAVITY.

To tho Editor. Sir,—The cabled statement of Sir Joseph Thompson that "a whole continent of the most important new scientific ide:i3 relating to physics has been dscovered," owing to the demonstration of the truth of Einstein' 3 theory, is not to bo taken as implying that the law of gravity has been upset. To know that light, during its passage from one part of the universe to another is subject to gravitational laws, is a matter of vast interest to tho physicist aud astronomer, but it cannot alter the fact that tho laws of graviy, as set forth by Newton, have frequently been successfully employed in demonstrating the mechanism of the universe It may bo brlloved, however, i that this new discovery will assist in ex- 1 plaining certain minute displacements in the 1 calculated, as compared with the true, position iof heavenly bodies, which displacements have ! hitherto baffled the most practical skill and 1 metriculou3 core of our computers. A special instance will assist in making this clear. Some years before 1910, when Jlaliey's comet returned, after an absence of nearly 75 years, Drs. Crommelin and Cowell undertook the arduous work of calculating the comet's exact path. Prom this x they were able to indicate where, and In what part of the heavens, the celestial visitant would first appear. So excellent was , the work of these skilful computers that, when i the earliest observation of the comet was j made, it was found that its actual position j was within about, two minutes of arc of the 1 calculated place, and the time of its arrival I was within three days of that predicted. Now, j this luiJ'hematical triumph had as its basis | known laws of gravity, and it may be that j futuro computations of tho comet's path, taking into account this newly discovered law of which we hear, will bo able to be still more exact, and enable those who follow us, to look at a particular time and in a particular Bpot In tho heavens with an absolute certainty of finding the returning body there —I am, etc., OSCAR BLUNDELL.