386 THE QUANTUM THEORY
1918, Rutherford commented on the Duane-Hunt results, 'There is at present no
physical explanation possible of this remarkable connection between energy and
frequency' [R7]. One can go on. The fact of the matter is that, even after Ein-
stein's photoelectric law was accepted, almost no one but Einstein himself would
have anything to do with light-quanta.
This went on until the early 1920s, as is best illustrated by quoting the citation
for Einstein's Nobel prize in 1922: 'To Albert Einstein for his services to theoret-
ical physics and especially for his discovery of the law of the photoelectric effect'
[A2]. This is not only an historic understatement but also an accurate reflection
on the consensus in the physics community.
To summarize: the enormous resistance to light-quanta found its roots in the
particle-wave paradoxes. The resistance was enhanced because the light-quan-
tum idea seemed to overthrow that part of electromagnetic theory believed to be
best understood: the theory of the free field. Moreover, experimental support was
long in coming and, even after the photoelectric effect predictions were verified,
light-quanta were still largely considered unacceptable. Einstein's own emphasis
on the provisional nature of the light-quantum hypothesis tended to strengthen
the reservations held by other physicists.
Right after March 1905, Einstein sat down and wrote his doctoral thesis. Then
came Brownian motion, then special relativity, and then the equivalence principle.
He did not return to the light-quantum until 1909. However, in 1906 he made
another important contribution to quantum physics, his theory of specific heats.
This will be the subject of the next chapter. We shall return to the light-quantum
in Chapter 21.
References
Al. A. B. Arons and M. B. Peppard, Am. J. Phys. 33, 367 (1965).
A2. S. Arrhenius in Nobel Lectures in Physics, Vol. 1, p. 478. Elsevier, New York,
1965.
Bl. U. Benz, Arnold Sommerfeld, p. 74. Wissenschaftliche Verlagsgesellschaft, Stutt-
gart, 1975.
B2. N. Bohr, Phil. Mag. 26, 1 (1913).
B3. , Nature 92, 231 (1913).
Cl. P. Curie and G. Sagnac, C. R. Acad. Sci. Paris 130, 1013 (1900).
Dl. W. Duane and F. L. Hunt, Phys. Rev. 6, 166 (1915).
El. A. Einstein, Forschungen undFortschritte 5, 248 (1929).
E2. , Naturw. 1, 1077 (1913).
E3. , in Albert Einstein: Philosopher-Scientist (P. A. Schilpp, Ed.), p. 2. Tudor,
New York, 1949.
E4. , in Out of My Later Years, p. 229. Philosophical Library, New York, 1950.
E5. ,AdP 17, 132(1905).
E6. ,Naturw. 1, 1077 (1913).
E7. ,AdP 14, 354 (1904).