User:Trev42M/Simon Jacques Prokhovnik

Simon Jacques Prokhovnik (* June 15th 1920 in Paris, † June 20th 1994 in Sydney) was an Australian mathematician, cosmologist and professor. Internationally, he is known in professional circles for his publications in the field of theoretical physics in connection with the special theory of relativity.

Life
Simon Jacques Prokhovnik, born June 1920 in Paris (France), was the son of Polish Jewish immigrants. In 1931 the family moved further, first to New Zealand and finally to Melbourne (Australia). In Melbourne, he spent two years as an administrative clerk, then as a biochemist and analytical chemist, also working part-time as a teacher. Meanwhile, he completed part-time studies at the University of Melbourne and received in the years 1944-46, the degrees of Bachelor of Arts and Bachelor of Science in mathematics and an honours degree in chemistry. Twenty years later, he received from the same university the degree of Master of Science. From 1955 to 1981 Prokhovnik taught mathematics at the University of New South Wales in Sydney, achieving he rank of Associate Professor. He then continued until 1992 as professor emeritus and taught cosmology. He placed particular emphasis on interdisciplinary teaching, including philosophical and political aspects of science. [1] From 1956, he was a member of the scientific Royal Society of New South Wales.

Contribution to relativity theory
Prokhovnik was one of the main proponents of neo-Lorentzian relativity from the 1960s onwards, inspired at first by the publications of the contemporary Australian electrical engineer Geoffrey Builder. This theory demonstrates how H A Lorentz's ether theory provides a physically intelligible basis for Albert Einstein's special theory of relativity (SRT). He published many articles and two books on the subject, in which he argued for the existence of a unique, universal substratum of space, related conceptually to the “luminiferous ether” of James Clerk Maxwell, but without speculating on the physical nature of the substratum. Unlike others favouring the Lorentzian approach to SRT, such as Herbert E. Ives, Prokhovnik held that Einstein's relativity theory is logically coherent [2] and that Einstein's initial assumptions (or postulates) - the full ( isotropic ) constancy of the measured speed of light and the universality of physical laws of nature - inevitably followed from a Lorentzian substratum-based approach, in spite of the latter's physically real anisotropy of the speed of light relative to any arbitrary observer. [3][4]. Prokhovnik discussed in his article "The Case for an Ether" the so-called clock or twin paradox, where, as he stressed, the solution in his theory is completely equivalent to that in SRT (p. 201). He claimed, however, that his theory could give a clearer understanding of the physical situation (pp. 206-207). [5] He also tried (following J A Bastin), to derive the Lorentz contraction by a modified law of gravity (pp. 201-204). [5] The "Neo-Lorentzian" position represented by Prokhovnik and others is still not the generally accepted and taught interpretation of special relativity theory. [6] [7]

The Logic of Special Relativity
This book published in 1967 by Prokhovnik came against the background of the debate between supporters and critics of relativity theory in the 1950s and 60s, in an attempt to settle the dispute. Prokhovnik examined the arguments on both sides and refuted the objections of critics such as Herbert Dingle, showing in detail the mathematical and logical consistency of relativity theory from three different perspectives: Einstein's SRT, the space-time representation of Hermann Minkowski and the neo-Lorentzian theory (the latter as already set out earlier in "The Case for an Ether"). He pointed to a number of ways in which mathematically equivalent representations make all the same physical predictions. The cause of the on-going disputes over SRT and paradoxes like the twin paradox Prokhovnik saw as arising from an inadequate understanding of SRT. Such issues could, in his view, be more straightforwardly explained from the Lorentzian point of view. He also contended that other issues such as the reciprocity of the Lorentz Transformations and the impossibility of measuring the one-way speed of light are also readily understood in Lorentzian terms. Deviating from the classical ether theory and on the basis of contemporary astronomical knowledge and the ideas of E A Milne, Prokhovnik proposed the gravitational centers of the galaxies as fixed points to define a fundamental reference system. This cosmological view of relativity, he developed later in his 1985 book "Light in Einstein's Universe" in the light of further astronomical discoveries.

Significant Publications
The Case for an Aether, The British Journal for the Philosophy of Science, Vol 14, No. 55 (Nov. 1963), p. 195-207 Neo-Lorentzian relativity, Journal of the Australian Mathematical Society, Volume 5, Issue 02, May 1965, p. 273-284 The Logic of Special Relativity, Cambridge University Press, Cambridge, 1967, ISBN 978-0521059992, also translated into French, second edition: New South Wales University Press, Sydney, 1978, ISBN 978-0909465728 Light in Einstein's Universe: The Role of Energy in Cosmology and Relativity, D. Reidel Publishing, Dordrecht, 1985, ISBN 978-9027720931 The Physical Interpretation of Special Relativity - a Vindication of Hendrik Lorentz, Zeitschrift fur Naturforschung 48a (1993), p. 925-931.

Weblinks
Short Biography

Biography in the Encyclopedia of Australian Science