TEL AVIV (Mar. 20)
Tel Aviv University and the Weizmann Institute of Science in Rehovoth agreed today to share credit for a series of scientific experiments which purportedly confirm Einstein’s theory that gravity acts in waves. The agreement followed a conciliatory meeting between the heads of the two institutions. The Weizmann Institute had objected to Tel Aviv University taking sole credit for the discovery.
The experiments were successfully conducted by Prof. Dror Sadeh of Tel Aviv University’s department of physics and astronomy. Prof. Sadeh used the Weizmann Institute’s geophysics observatory near Eilat, headed by Prof. Ari Ben Menahem. Tel Aviv U. announced the results on March 17, crediting Prof. Sadeh. Today, however, both institutions acknowledged that Prof. Sadeh and Prof. Ben Menahem were partners in the discovery.
Albert Einstein predicted in 1917 that gravity nets in waves. The prediction was part of his General Theory of Relativity. But it could not be confirmed experimentally because the waves are extremely weak. The experiments conducted by Profs. Sadeh and Ben Menehem made use of the 1967 discovery of pulsars, a type of pulsating star assumed to have very high density and very rapid rotation. According to Einstein’s theory, such bodies must emit gravity waves.
Prof. Sadeh’s innovation was to use the earth as a detector, but because the effects of the waves is very small, a sophisticated electronic system had to be built by the university and the advanced equipment at the Weizmann Institute facility had to be employed.
According to the announcement the experiment proved the existence of gravitational waves which up to now were merely an assumption; that pulsars are neutron stars having high density and a high rate of rotation; and that a seismograph on earth can serve as an astronomical telescope which measures the movements of stars.