Einstein (118 page)

16
. Einstein, “On a Heuristic Point of View Concerning the Production and Transformation of Light,” Mar. 17, 1905.

17
. “We are startled, wondering what happened to the waves of light of the 19th century theory and marveling at how Einstein could see the signature of atomic discreteness in the bland formulae of thermodynamics,” says the science historian John D. Norton. “Einstein takes what looks like a dreary fragment of the thermodynamics of heat radiation, an empirically based expression for the entropy of a volume of high-frequency heat radiation. In a few deft inferences he converts this expression into a simple, probabilistic formula whose unavoidable interpretation is that the energy of radiation is spatially localized in finitely many, independent points.” Norton 2006c, 73. See also Lightman 2005, 48.

18
. Einstein’s paper in 1906 noted clearly that Planck had not grasped the full implications of the quantum theory. Apparently, Besso encouraged Einstein not to make this criticism of Planck too explicit. As Besso wrote much later, “In helping you edit your publications on the quanta, I deprived you of a part of your glory, but, on the other hand, I made a friend for you in Planck.” Michele Besso to Einstein, Jan. 17, 1928. See Rynasiewicz and Renn, 29; Bernstein 1991, 155.

19
. Holton and Brush, 395.

20
. Gilbert Lewis coined the name “photon” in 1926. Einstein in 1905 discovered a quantum of light. Only later, in 1916, did he discuss the quantum’s momentum and its zero rest mass. Jeremy Bernstein has noted that one of the most interesting discoveries Einstein did
not
make in 1905 was the photon. Jeremy Bernstein, letter to the editor,
Physics Today
, May 2006.

21
. Gribbin and Gribbin, 81.

22
. Max Planck to Einstein, July 6, 1907.

23
. Max Planck and three others to the Prussian Academy, June 12, 1913, CPAE 5: 445.

24
. Max Planck,
Scientific Autobiography
(New York: Philosophical Library, 1949), 44; Max Born, “Einstein’s Statistical Theories,” in Schilpp, 163.

25
. Quoted in Gerald Holton, “Millikan’s Struggle with Theory,”
Europhysics News
31 (2000): 3.

26
. Einstein to Michele Besso, Dec. 12, 1951, AEA 7-401.

27
. Completed Apr. 30, 1905, submitted to the University of Zurich on July 20, 1905, submitted to
Annalen der Physik
in revised form on Aug. 19, 1905, and published by
Annalen der Physik
Jan. 1906. See Norton 2006c and www.pitt.edu/~jdnorton/Goodies/Einstein_stat_1905/.

28
. Jos Uffink, “Insuperable Difficulties: Einstein’s Statistical Road to Molecular Physics,”
Studies in the History and Philosophy of Modern Physics
37 (2006): 37, 60.

29
. bulldog.u-net.com/avogadro/avoga.html.

30
. Rigden, 48–52; Bernstein 1996a, 88; Gribbin and Gribbin, 49–54; Pais 1982, 88.

31
. Hoffmann 1972, 55; Seelig 1956b, 72; Pais 1982, 88–89.

32
. Brownian motion introduction, CPAE 2 (German), p. 206; Rigden, 63.

33
. Einstein, “On the Motion of Small Particles Suspended in Liquids at Rest Required by the Molecular-Kinetic Theory of Heat,” submitted to the
Annalen der Physik
on May 11, 1905.

34
. Einstein 1949b, 47.

35
. The root mean square average is asymptotic to ff2n/?. Good analyses of the relationship of random walks to Einstein’s Brownian motion are in Gribbin and Gribbin, 61; Bernstein 2006, 117. I am grateful to George Stranahan of the Aspen Center for Physics for his help on the mathematics behind this relationship.

36
. Einstein, “On the Theory of Brownian Motion,” 1906, CPAE 2: 32 (in which he notes Seidentopf ’s results); Gribbin and Gribbin, 63; Clark, 89; Max Born, “Einstein’s Statistical Theories,” in Schilpp, 166.

CHAPTER SIX: SPECIAL RELATIVITY

1
. Contemporary historical research on Einstein’s special theory begins with Gerald Holton’s essay, “On the Origins of the Special Theory of Relativity” (1960), reprinted in Holton 1973, 165. Holton remains a guiding light in this field. Most of his earlier essays are incorporated in his books
Thematic Origins of Scientific Thought: Kepler to Einstein
(1973),
Einstein, History and Other Passions
(2000), and
The Scientific Imagination,
Cambridge, Mass.: Harvard University Press, 1998.

Einstein’s popular description is his 1916 book,
Relativity: The Special and the General Theory
, and his more technical description is his 1922 book,
The Meaning of Relativity
.

For good explanations of special relativity, see Miller 1981, 2001; Galison; Bernstein 2006; Calder; Feynman 1997; Hoffmann 1983; Kaku; Mermin; Penrose; Sartori; Taylor and Wheeler 1992; Wolfson.

This chapter draws on these books along with the articles by John Stachel; Arthur I. Miller; Robert Rynasiewicz; John D. Norton; John Earman, Clark Glymour, and Robert Rynasiewicz; and Michel Jannsen listed in the bibliography. See also Wertheimer 1959. Arthur I. Miller provides a careful and skeptical look at Max Wertheimer’s attempt to reconstruct Einstein’s development of special relativity as a way to explain Gestalt psychology; see Miller 1984, 189–195.

2
. See Janssen 2004 for an overview of the arguments that Einstein’s attempt to extend general relativity to arbitrary and rotating motion was not fully successful and perhaps less necessary than he thought.

3
. Galileo Galilei,
Dialogue Concerning the Two Chief World Systems
(1632), translated by Stillman Drake, 186.

4
. Miller 1999, 102.

5
. Einstein, “Ether and the Theory of Relativity,” address at the University of Leiden, May 5, 1920.

6
. Ibid.; Einstein 1916, chapter 13.

7
. Einstein, “Ether and the Theory of Relativity,” address at the University of Leiden, May 5, 1920.

8
. Einstein to Dr. H. L. Gordon, May 3, 1949, AEA 58-217.

9
. See Alan Lightman’s
Einstein’s Dreams
for an imaginative and insightful fictional rumination on Einstein’s discovery of special relativity. Lightman captures the flavor of the professional, personal, and scientific thoughts that might have been swirling in Einstein’s mind.

10
. Peter Galison, the Harvard science historian, is the most compelling proponent of the influence of Einstein’s technological environment. Arthur I. Miller presents a milder version. Among those who feel that these influences are overstated are John Norton, Tilman Sauer, and Alberto Martinez. See Alberto Martinez, “Material History and Imaginary Clocks,”
Physics in Perspective
6 (2004): 224.

11
. Einstein 1922c. I rely on a corrected translation of this 1922 lecture that gives a different view of what Einstein said; see bibliography for an explanation.

12
. Einstein, 1949b, 49. For other versions, see Wertheimer, 214; Einstein 1956, 10.

13
. Miller 1984, 123, has an appendix explaining how the 1895 thought experiment affected Einstein’s thinking. See also Miller 1999, 30–31; Norton 2004, 2006b. In the latter paper, Norton notes, “[This] is untroubling to an ether theorist. Maxwell’s equations
do
entail quite directly that the observer would find a frozen waveform; and the ether theorist does not expect frozen waveforms in our experience since we do not move at the velocity of light in the ether.”

14
. Einstein to Erika Oppenheimer, Sept. 13, 1932, AEA 25-192; Moszkowski, 4.

15
. Gerald Holton was the first to emphasize Föppl’s influence on Einstein, citing the memoir by his son-in-law Anton Reiser and the German edition of Philipp Frank’s biography. Holton 1973, 210.

16
. Einstein, “Fundamental Ideas and Methods of the Theory of Relativity” (1920), unpublished draft of an article for
Nature
, CPAE 7: 31. See also Holton 1973, 362–364; Holton 2003.

17
. Einstein to Mileva Mari
, Aug. 10, 1899.

18
. Einstein to Mileva Mari
, Sept. 10 and 28, 1899; Einstein 1922c.

19
. Einstein to Robert Shankland, Dec. 19, 1952, says that he read Lorentz’s book before 1905. In his 1922 Kyoto lecture (Einstein 1922c) he speaks of being a student in 1899 and says, “Just at that time I had a chance to read Lorentz’s paper of 1895.” Einstein to Michele Besso, Jan. 22?, 1903, says he is beginning “comprehensive, extensive studies in electron theory.” Arthur I. Miller provides a good look at what Einstein had already learned. See Miller 1981, 85–86.

20
. This section draws from Gerald Holton, “Einstein, Michelson, and the ‘Crucial’ Experiment,” in Holton 1973, 261–286, and Pais 1982, 115–117. Both assess Einstein’s varying statements. The historical approach has evolved over the years. For example, Einstein’s longtime friend and fellow physicist Philipp Frank wrote in 1957, “Einstein started from the most prominent case in which the old laws of motion and light propagation had failed to yield to the observed facts: the Michelson experiment” (Frank 1957, 134). Gerald Holton, the Harvard historian of science, wrote in a letter to me about this topic (May 30, 2006): “Concerning the Michelson/Morley experiment, until three or four decades ago practically everyone wrote, particularly in textbooks, that there was a straight line between that experiment and Einstein’s special relativity. All this changed of course when it became possible to take a careful look at Einstein’s own documents on the matter ... Even non-historians have long ago given up the idea that there was a crucial connection between that particular experiment and Einstein’s work.”

21
. Einstein 1922c; Einstein toast to Albert Michelson, the Athenaeum, Caltech, Jan. 15, 1931, AEA 8-328; Einstein message to Albert Michelson centennial, Case Institute, Dec. 19, 1952, AEA 1-168.

22
. Wertheimer, chapter 10; Miller 1984, 190.

23
. Robert Shankland interviews and letters, Feb. 4, 1950, Oct. 24, 1952, Dec. 19, 1952. See also Einstein to F. G. Davenport, Feb. 9, 1954: “In my own development, Michelson’s result has not had a considerable influence, I even do not remember if I knew of it at all when I wrote my first paper on the subject. The explanation is that I was, for general reasons, firmly convinced that there does not exist absolute motion.”

24
. Miller 1984, 118: “It was unnecessary for Einstein to review every extant ether-drift experiment, because in his view their results were ab initio [from the beginning] a foregone conclusion.” This section draws on Miller’s work and on suggestions he made to an earlier draft.

25
. Einstein saw the null results of the ether-drift experiments as support for the
relativity principle, not (as is sometimes assumed) support for the postulate that light always moves at a constant velocity. John Stachel, “Einstein and Michelson: The Context of Discovery and Context of Justification,” 1982, in Stachel 2002a.