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Robert S. Shankland



         


Robert S. Shankland (1908–1982) was an American physicist and historian.

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Biography

Shankland was an undergraduate at the Case School for Applied Sciences from 1925-1929 and received his masters degree in 1933. He received his Ph.D. in 1935 for work on photon scattering with Arthur Compton at the University of Chicago. Shankland's other research included work on the ionosphere and standard frequency regulations from 1929-1930 with the US National Bureau of Standards, and work on sonar for submarine warfare in World War II.

Shankland's final report on the Albert Michelson's Irvine Ranch experiments was published in 1933. Shankland in the British Journal Nature give the historical background of how Einstein formulates the first two principles, in 1905, of the Special Theory of Relativity from the Michelson-Morley experiment. Shankland believed that the accepted direct explanation for the Michelson-Morley experiment is provided by the special theory of relativity given by Albert Einstein in 1905. Shankland recorded that Michelson's Santa Ana trip was to look at the science of the aether. Physicists consider the results of the tests on Mount Wilson more accurate. Computer analysis after Miller's death on the available data has proven that the shifts were statistically significant. The interferometry apparatus work continued from 1886 until July 1887 (including the buildings on the Case and Western Reserve campuses).

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Analysis of the Miller Experiment

Shankland performed a debated analysis on how Dayton Miller's interferometric results could be caused by thermal fluctuations and therefore be consistent with special relativity; Shankland's explanation is now accepted by most mainstream scientists. He was in the physics department of Case Western Reserve University from 1940-1958 (becoming its chairman), worked on neutrino experiments with Argonne National Laboratory from 1953-1969, and had other interests including the history of relativity and architectural acoustics.

In 1925-1926, Dayton Miller performed interferometric observations at Mount Wilson, similar to the Michelson-Morley experiment, that appeared to reflect a measurable drift of the Earth through the luminiferous aether, in apparent contradiction with other experiments of that type and with relativity's prediction that no aether should be observable. Shankland believed that Dayton Miller's research was a major obstacle to and overshadowed any consideration of a Nobel Prize be awarded to Albert Einstein for his relativity theory.

In 1955, Shankland published a paper analyzing Miller's data, arguing that "the small periodic fringe displacements found by Miller are due in part to statistical fluctuations in the readings of the fringe positions in a very difficult experiment" and "the remaining systematic effects are ascribed to local temperature conditions." Moreover, he argues that the thermal gradients responsible for the effects "were much more troublesome at Mount Wilson than those encountered by experimenters elsewhere, including Miller himself in his work done at Case in Cleveland." Thus a large, but indefinite number of, mainstream scientists today hold the conviction that any signal that Miller observed was the result of experimenter's bias, which was a common source of systematic error before modern experimental techniques were developed (ed, Miller did publish an early textbook on experimental techniques; cf., Dayton Miller, Ginn & Company, 1903). In a 1973 review paper on the experimental development of relativity, Shankland included an August 31, 1954 letter to him by Einstein agreeing with his analysis. (Shankland had sent Einstein a manuscript prior to its publication.) Einstein wrote:

I thank you very much for sending me your careful study about the Miller experiments. Those experiments, conducted with so much care, merit, of course, a very careful statistical investigation. This is more so as the existence of a not trivial positive effect would affect very deeply the fundament of theoretical physics as it is presently accepted.
You have shown convincingly that the observed effect is outside the range of accidental deviations and must, therefore, have a systematic cause. You made it quite probable that this systematic cause has nothing to do with "ether-wind," but has to do with differences of temperature of the air traversed by the two light bundles which produced the bands of interference. Such an effect is indeed practically inevitable if the walls of the laboratory room have a not negligible difference in temperature.
It is one of the cases where the systematic errors are increasing quickly with the dimension of the apparatus.

In Shankland's re-analysis, no statistically significant signal for the existence of aether was found. The analysis is accepted by mainstream physicists, the denial in the existence of the aether is nearly universal, and Miller's observed signal was purportedly the result of experimenter's bias. Nevertheless, there are scientists who argue that Shankland's analysis was incorrect and that Miller's results were inconsistent with standard relativity. For example, A. K. Timiriazev, R. A. Monti (Physics Essays 9, 1996) and M. Allais (Comptes Rendus de l'Academie des Sciences 327, 1999) later disproved Shankland's allegation. These arguments, however, have not been published in a more prestigious scientific journal, nor are they accepted widely by physicists. William Broad and Nicholas Wade (Betrayers of the Truth: Fraud in Science; 1983) have stated that scientists should have reviewed Miller's research more seriously, in lieu of incompetence and unprofessional conduct.

Some believe that the "signal" that Miller observed in 1933 is actually composed of points that are an average of several hundred measurements each, and the magnitude of the signal is more than 10 times smaller than the resolution with which the measurements were recorded. As of 2004, there has been more of Miller's papers from the possession of R. S. Shankland to surface and they are awaiting future analysis.

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External links and references


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Appendix: partial list of Shankland's publications





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