Difference between revisions of "Arthur Eddington"

Revision as of 05:23, February 13, 2016

Sir Arthur Eddington (1882–1944) was a liberal British astronomer best known for venturing out on a boat off Africa in 1919 to observe the bending of starlight around the sun during a total eclipse. The theory of general relativity of Albert Einstein predicts twice the bending of light around massive objects compared to Newton's theory, and an eclipse is required to darken the sun so that the starlight may be seen in proximity to the sun.

Eddington was a conscientious objector during World War I. He needed an important-sounding project to justify his avoidance of military service, and the eclipse expedition was perfect for him.

Eddington liked publicity and probably dreamed of winning a Nobel Prize, and upon his return to England declared that his observations proven the theory of relativity. That was good enough for reporters and historians, but the Nobel committee was not impressed and declined to give him an award. Recent analysis of Eddington’s work revealed that he was biased in selecting his data, and that overall his data was inconclusive about the theory of relativity.^[1]

Eddington next promoted the theory of relativity to the English-speaking world in his Mathematical Theory of Relativity (1923). As the title suggests, this theory was more a mathematical vision of how the universe should be, rather than what it actually was. When a reporter asked Eddington whether only three people even understood the theory, Eddington supposedly arrogantly retorted, "Who's the third?"

But Eddington did not fare well after that. He strongly opposed a theory about massive stars known as white dwarves put forth by Indian physicist Subrahmanyan Chandrasekhar, but Eddington was proven wrong and Chandrasekhar later won a Nobel Prize for his work. Eddington finally lost all credibility when he first insisted that a physical constant (the fine structure constant) measured to be close to 1/136 must precisely equal 1/136 to make the math easier, but when later measurements suggested a value closer to 1/137 Eddington insisted that it must precisely equal to 1/137 instead. He was wrong both times.

References

↑ http://arxiv.org/abs/astro-ph/0102462

[1] ttp://arxiv.org/abs/astro-ph/0102462

[1]

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 [[Image:Eddington 2.jpg|right|thumb]]
-Sir '''Arthur Eddington''' (1882–1944) was a [[British]] scientist, science writer, and science "popularizer", somewhat in the mold of [[Carl Sagan]] and [[Neil deGrasse Tyson]] in modern times.<ref>''The Nature of the Physical World'', Arthur Eddington, MacMillan, 1929</ref>
+Sir '''Arthur Eddington''' (1882–1944) was a [[liberal]] [[British]] astronomer best known for venturing out on a boat off Africa in 1919 to observe the bending of starlight around the sun during a total [[eclipse]].  The [[theory of relativity|theory of general relativity]] of [[Albert Einstein]] predicts twice the bending of light around massive objects compared to [[Isaac Newton|Newton]]'s theory, and an eclipse is required to darken the sun so that the starlight may be seen in proximity to the sun.
-In the early decades on the 20<sup>th</sup> century, the world was in awe of two new theories of "modern physics"&mdash;[[Relativity]] and [[Quantum Mechanics]].  Both were known for being very abstruse.  He popularized them, both for experts and for the general public.  He particularly worked on getting relativity better known, both by the scientific community and by the public.  [[General Relativity]] was something he worked especially hard at.
+Eddington was a [[conscientious objector]] during [[World War I]]. He needed an important-sounding project to justify his avoidance of military service, and the eclipse expedition was perfect for him.
-He is best known for his observations of the bending of light from stars in the vicinity of the sun during a total [[eclipse]].  This had been predicted by General Relativity, but the theory was so esoteric that even the scientific community had a difficult time with it.  The problem was compounded by the fact that Einstein was German, and the controversy was around the time of [[World War I]].  His claimed success (not fully justified&mdash;see below) made Einstein a household name, even though the public still understood virtually nothing about relativity.
+Eddington liked publicity and probably dreamed of winning a [[Nobel Prize]], and upon his return to England declared that his observations proven the theory of relativity.  That was good enough for reporters and historians, but the Nobel committee was not impressed and declined to give him an award.    '''''Recent analysis of Eddington’s work revealed that he was biased in selecting his data, and that overall his data was inconclusive about the theory of relativity'''''.<ref>http://arxiv.org/abs/astro-ph/0102462</ref>
-Eddington was a [[conscientious objector]] during [[World War I]].<!-- He needed an important-sounding project to justify his avoidance of military service, and the eclipse expedition was perfect for him.  Not so!  The eclipse expedition was in 191, after the war was over. -->
-==The Eclipse of 1919==
-The [[theory of relativity|theory of general relativity]] of [[Albert Einstein]] predicts that light from stars grazing the sun will be deflected by 1.75 arc-seconds.  [[Isaac Newton|Newton]]'s "corpuscular" theory predicts a deflection of 0.875 arc seconds.<ref>Johann von Soldner calculated this deflection, and showed that would be independent of the (presumably very fast) speed of the "corpuscles", in 1801.</ref>  Scientists had mostly discarded Newton's theory in terms of the "wave" theory, which didn't address the issue at all.  The predicted deflections were near the limits of the technology of the time.  Furthermore, an eclipse was required to darken the sun so that the starlight may be seen in proximity to the sun.
-Eddington mounted two expeditions, with the best equipment available, to observe the solar eclipse of May 29, 1919.  One team went to Sobral, Brazil, and the other went to the island of Principe, off the African coast.  Upon his return, Eddington declared that he had successfully measured a deflection of 1.75 arc-seconds.  Einstein (and, to a lesser extent, Eddington) immediately became an international superstar of science.  (Neither Einstein nor Eddington won a [[Nobel Prize]] for this.)
-Recent analysis of Eddington’s work revealed that he was biased in selecting his data, and that overall his data were inconclusive about the theory of relativity.<ref>http://arxiv.org/abs/astro-ph/0102462</ref>  Modern techniques for analyzing data from experiments involves extremely careful statistical analysis of the data, and generally demands a "5 sigma" level of statistical certainty, which means that there is only a one-in-three-million chance that the measurements came out that way by chance rather than by the phenomenon being measured.
-Eddington's observation protocol was somewhat muddled by an incorrect initial calculation, by several people including Einstein himself, of what the effect would be, and some "cherry picking" of the data to be used <ref>''Einstein's Luck'', John Waller, Oxford University Press, ISBN 0-19-860719-9</ref>.  The data selection could be considered "manipulation" or "fudging", by Eddington, who had a personal stake in the outcome.  His analysis techniques would not pass muster today.  Nevertheless, the deflection has been verified with ever-increasing precision in subsequent eclipses, and, with exquisite precision, in the observations of quasar 3C273.
 Eddington next promoted the theory of relativity to the English-speaking world in his ''Mathematical Theory of Relativity'' (1923).  As the title suggests, this theory was more a mathematical vision of how the universe should be, rather than what it actually was.  When a reporter asked Eddington whether only three people even understood the theory, Eddington supposedly arrogantly retorted, "Who's the third?"

Difference between revisions of "Arthur Eddington"

Revision as of 05:23, February 13, 2016

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