¹ A Realistic Universe, Macmillan, 1916, 1931.

² Sidelight's of Relativity, 1922, p. 17.

³ “Coherence in the Physical World”, Philosophy of Science, Vol. 9, No. 4, p. 333.

⁴ Op. cit., pp. 19, 20.

⁵ Science and Hypothesis, p. 17.

⁶ Einstein's theories of relativity have been epoch-making in their influence on science, but while they have solved many problems, they have raised many others. For example, the special theory of relativity assumes the absolute velocity of light and uses it as a basis of comparison of perspectives from different frames of reference. But what is meant by the velocity of light? P. W. Bridgman denies that light travels. It certainly does not travel in the relative sense. If velocity as applied to light has a different meaning from velocity as applied to relative frames of reference, what basis have we for comparison? Furthermore, we are told, in the general theory, that the velocity of light is not absolute. Light is supposed to be “retarded” by gravitational fields. But the effect of gravitational fields is not to slow down the velocity of light but to reduce its energy by “shaving off” (to use Zwicky's phrase) quanta of energy from the photons of light, shifting it towards the red end of the spectrum. But red light has the same velocity as blue light. Dr. Strömberg has shown that the light from the far-off spiral nebulae has the same velocity as light from nearer sources, though there is a red shift. If light traveled like bodies, then its velocity would be slowed-up in gravitational fields. But its velocity is not slowed up. If velocity of light is meaningless in terms of velocity of bodies, how are we to understand the Michel-son effect or rather absence of effect? If light is refracted and reflected from one material part to another that would, of course, increase the distance, but it would not affect the velocity. The velocity of light is constant, but what does it mean? The interpretation of Einstein's formula of general relativity, as implying that the geometry of space is altered (“warped”) in the neighborhood of matter, is difficult to reconcile with Einstein's conception of space-ether as having no parts and as without any mechanicl or kinematical properties. How could such a space be affected by matter? Is it not more conceivable that the law of the inverse square does not hold for “grazing” distances of light? It seems to hold approximately for the distances within the solar system with which Newton was concerned, though it does not seem to hold for Mercury because of its nearness to the sun. What about the vast distances revealed by spiral nebulae? Einstein's formula seems to work. But what does it mean? Perhaps Einstein is more sophisticated than nature. An interpretation nearer to common sense may prevail in the end. In the meantime, mathematical physicists are having a field day. But should they not avoid confusing types?

⁷ A. S. Eddington, The Nature of the Physical World, 1928, p. 101.

⁸ Sir Arthur Eddington, The Expanding Universe, 1933, pp. 33 ff.

8a Professor W. M. Malisoff has suggested that heat has no privileged position in dynamics. “The Problems of Thermodynamics,” Philosophy of Science, Vol. 8, No. 3, pp. 399 ff.

⁹ J. E. Boodin, Cosmic Evolution, 1925, pp. 424 ff.

¹⁰ Embryonic Development and Induction, 1938, ch. 15.

¹¹ Three Interpretations of the Universe, 1934, ch. V, esp. pp. 215–228.

¹² The Philosophy of Peirce, ed. by Justus Buchler, 1940, p. 156.

¹³ J. E. Boodin, A Realistic Universe, ch. III.