Published online by Cambridge University Press: 30 January 2009
In connection with the special theory of relativity, Einstein made use of a now familiar thought experiment1 involving two lightning flashes, a railway train, and an embankment. Whether he used it merely to help explain the theory to others or whether it played a role in the theory's very generation as well is perhaps a matter of conjecture. However, physicist Richard Feynman, for one, believes that Einstein first conceived his theories in the visualizations of thought experiments and developed their mathematical formulations afterwards. According to a recent magazine essay, ‘Einstein came to an understanding about relativity by imagining people going up in elevators and beaming light back and forth between rocket ships.
1 In the present paper I rely on presentations and discussions of Einstein's thought found in the following works: Albert Einstein, ‘On the Electrodynamics of Moving Bodies’, reprinted as an appendix to Arthur I., Miller, Albert Einstein's Special Theory of Relativity (Reading, Mass.: Addison-Wesley, 1981); Albert Einstein, Relativity: The Special and the General Theory (New York: Bonanza Books, 1961); Richard P. Feynman, Robert, B. Leighton and Matthew Sands, The Feynman Lectures on Physics, Vol I (Reading, Mass., Palo Alto; London: Addison-Wesley, 1963); Francis, W. Sears and Robert, W. Brehme, Introduction to the Theory of Relativity (Reading, Mass., Menlo Park, Calif., London, Don Mills, Ontario: Addison-Wesley, 1968); and Issac Asimov, Understanding Physics, Vol II (New York: New American Library, 1969). For helpful comments I am grateful to my colleague Catherine Wilson, to students Glen Stohr and Michael Medler, and to my good friend Robert D. Hartwig.Google Scholar
2 K. C. Cole, ‘On Imagining the Unseeable’, Discover (December 1982) (Los Angeles: Time), 72.
3 See Feynman, Leighton and Sands, op. cit., 15-8. Cf. Sears and Brehme, op. cit., 35.
4 Asimov, op. cit., 102. Cf. Einstein, Relativity: The Special and the General Theory, 59-60.Google Scholar
5 Einstein, Relativity: The Special and the General Theory, 17.Google Scholar
6 Op. cit., 5.
7 Op. cit., 8.
8 Op.cit.,18.
9 Op.cit.,5.
10 In the following discussion of this question I am indebted to F. I. Dretske's illuminating essay ‘Can Events Move?’, Mind LXXVI, No. 304 (October 1967), 479-492.
11 ‘Why the Special Theory of Relativity is Correct’, reprinted in H., Dingle, Science at the Crossroads (London: Martin Brian and O'Keeffe, 1972), 242.Google Scholar
12 This is Dretske's list of datable but non-clockable events. See op. cit., 482. The list is not without its difficulties, but it serves to indicate that the class of ‘entities’ to which the flash belongs is a familiar one.
13 This is G. E. M. Anscombe's formulation. See The Collected Papers of G. E. M. Anscombe, Vol. II (Metaphysics and the Philosophy of Mind), (Minneapolis: University of Minnesota Press, 1984), 154.Google Scholar
14 Anscombe, op. cit., 156 (my italics). I suspect Miss Anscombe would disagree with my claim that the flash may be understood to bring about the existence of its place. It seems that for her only an event ‘which was the first’, an event occurring not only before all other events but evidently also before the existence of any objects, brings about the existence of a place. However, if she agreed that the laboratory occupants' reaction to what they witness is natural and intelligible, perhaps she would allow that the flash too, though not the first event, may bring about the existence of a place.
15 An Essay Concerning Human Understanding, II, xxvii, sec. 1.
16 P., T. Geach, Logic Matters (Berkeley and Los Angeles: University of California Press, 1972), 312.Google Scholar