BOOK REVIEW
Paradigm Lost
Suman Seth
Einstein's Jury: The Race to Test Relativity. Jeffrey
Crelinsten. xxx + 397 pp. Princeton University Press, 2006. $35.
In a letter written on February 6, 1920, astronomer Keivin Burns of
California's Lick Observatory expressed his doubts about Einstein's
general theory of relativity. "Of course no one at Lick
believes in the Einstein effect," he wrote, referring to the
gravitational redshift in spectroscopic lines predicted by the
theory, "it being contrary to philosophy, judgment, and horse
sense. But since so much is being said on the subject it is
necessary to be interested. It may take a long while to show the
error of the ways of the English astronomers."
The timing, location and subject of Burns's epistle are all central
to our understanding of the early reception and testing of one of
the pillars of modern physical theory. Most popular accounts of
Einstein's theory tend to depict the 1919 eclipse expedition, led by
Arthur Stanley Eddington, as the crucial test for general
relativity. Eddington's announcement that the paths of starlight
were deflected or "bent" by the Sun's gravitational field
by almost exactly the amount predicted by the theory was met with
incredulity and amazement among scientists and sparked an
international press furor. Within two weeks of the first media
reports, the British humor magazine Punch recorded in lines
of doggerel that an English "patriot" had been forced to
write a funeral march, "To record, as he said, that a
Jewish-Swiss-Teuton / Had partially scrapped the Principia
of Newton."
As Jeffrey Crelinsten's crisply written and impressively researched
book shows, however, the "patriot fiddler-composer of
Luton" gave up his faith in Newtonian physics long before
American astronomers were convinced to do so. The ongoing skepticism
of the Americans was to have real import, for in the 1920s it was
increasingly to the Lick and Mount Wilson observatories, both in
California, that European and British scientists would look for the
final word on the validity of a theory that few professed to
understand fully.
There is no dearth of literature on Einstein, but two elements make
Einstein's Jury stand out: First, it looks at
astronomers, rather than physicists or mathematicians, providing a
focus that comparatively few others have offered. Second, and even
more important, Crelinsten's book crosses the Atlantic to offer a
genuinely novel perspective on the question of relativity's
reception. (The most notable exception to both of these points is
historian Klaus Hentschel's extensive work, of which Crelinsten
makes good use.)
American scientists repeatedly bemoaned their inability to deal with
the theoretical intricacies of Einstein's new formulation of the
nature of space and time. As a result, theory takes a back seat in
Crelinsten's story; he stresses instead the ways in which
observational materials and practices changed in order to grapple
with "the Einstein problem." At the same time, Crelinsten
uses debates over Einstein's theory as a lens through which to
examine the tensions within the U.S. astronomical community, as
better-funded and better-equipped astronomers in the West came to
accept and later argue for general relativity in the face of
skepticism and even hostility from their eastern colleagues.
The book is divided into four parts, the first two of which deal
with the years between Einstein's publication in 1905 of what would
later become known as his "special theory" and the initial
responses to the 1919 eclipse expedition. This is the material,
especially the European side of the story, that will be more
familiar to the specialist. But the account is deftly told, and we
arrive at the end of the 1910s with a good sense of the major
contours of international astronomy and a real sense of surprise
that the English would so willingly ignore the negative or neutral
evidence from the Lick in favor of Eddington's eclipse data.
American astronomers critical of the theory clearly felt the same
surprise and accused their British colleagues of launching a
publicity campaign on Einstein's behalf, a claim that recent
scholarship tends to support (as shown, for example, in articles by
Alistair Sponsel in the British Journal for the History of
Science and by Matthew Stanley in Isis).
Part three covers the years between 1920 and 1925, as researchers at
Mount Wilson took up the redshift problem in earnest and Lick
observers continued their work on the gravitational bending of
light. In 1922 the Lick would confirm the results of Eddington's
expedition with data deemed so solid that the Lick's director,
William Wallace Campbell, informed Frank Dyson, Britain's Astronomer
Royal, that the observatory would not bother with further testing of
the problem at the next eclipse in September 1923. On the basis of
redshift data collected during that eclipse, even the formerly
reticent astronomer Charles E. St. John of Mount Wilson stepped
forward in support of the theory.
For more cautious and critical researchers, however, the 1923
results were no more decisive than those of 1919. The director of
the Allegheny Observatory in Pittsburgh, Heber Doust Curtis, for
example, was forced to concede the existence of a deflection larger
than that predicted by Newtonian theory, but he still balked at
accepting Einstein's theory. He held out hope that Newtonian
mechanics would eventually explain both evidence from the Lick and
the perihelion of Mercury. (The perihelion of a planet's
orbit—that is, the point at which the planet passes closest to
the Sun—shifts slowly over time. It had earlier been shown
that Newtonian mechanics alone could not easily explain the movement
of the perihelion of Mercury. Einstein's theory, however, could
account for it.)
Curtis was not alone in his opposition. Crelinsten delineates the
ways in which postwar, anti-European sentiment played into the
debate, as some scientists were critical of Einstein personally, as
well as his theory. T. J. J. See, astronomer at the Mare Island Navy
Yard, would make use of the vicious propaganda promoted in Germany
by a group of anti-Semitic scientists who accused Einstein of
plagiarism. Charles Lane Poor, professor of celestial mechanics at
Columbia University, referred to Einstein as "the bolshevist of
science" and called his theory "the most dangerous
doctrine of modern times." Curtis remained strongly anti-German
and complained to Campbell at one point that "the personnel
list of Lick and Mount Wilson are getting to read too much like a
page of a Swedish directory."
Crelinsten's story shifts in the fourth section, which deals with
the "final acceptance" of Einstein's theory in the second
half of the 1920s. He notes that one of the effects of strident
antirelativist attacks was to shift the positions of the directors
of the leading observatories in the western U.S. from their studied
neutrality to an open advocacy. "The nature of the ensuing
debates," he writes, "forced Lick and Mount Wilson
astronomers to go beyond defending their observations. They ended up
supporting the theory."
The book's symmetry of description—strong when discussing Old
and New World astronomers—wavers somewhat in this section. No
similar equality functions between leading U.S. institutions and the
individuals who would remain opposed to relativity. Campbell's
actions, for example, are depicted as "natural" and
"appropriate" while the motives of See, Poor and Curtis
are both personal and "suspect." This treatment seems
inadequate for Curtis, in particular, who is portrayed earlier in
the book as far too rich and multifaceted a character to be
explained so simply.
In spite of this shortcoming, the book remains an impressive one
throughout. It belongs to that rare breed of works that will be of
genuine interest and enjoyment to the casual reader while at the
same time being required reading for the specialist.