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The third volume of The Collected Papers of Albert Einstein, The Swiss
Years: Writings, 1909-1911 (Princeton University Press, pp 437, £65/
$85 hbk, £19.50/ $29.95 pbk) is a record of the gap that lies between
special relativity and general relativity. His paper of June 1911, for example,
shows him groping toward the theory of general relativity but predicts the
wrong angle in the bending of light by gravity. Luckily, no eclipse occurred
that year to test Einstein’s prediction that a ray of light travelling past
the Sun would undergo a deflection amounting to 0.83 seconds of an arc.
By the time a solar eclipse was used to test the theory in March 1919, Einstein
had revised the deflection to 1.74 seconds of an arc, and the Royal Astronomical
Society observed this, so confirming a key part of his theory of general
relativity.