In "Brown Responds to Lippard" (Creation/Evolution XXV), Walter Brown makes a number of claims about secular changes in the values of fundamental constants of physics. Since much of what he says is misleading and some of it is wrong, a response is in order.
Brown quotes Troitskii as supporting a decay in the speed of light c. However, Troitskii is talking about decay rates that are a million times smaller than young-earth creationists require, so this does not help their case. A careful reading of Troitskii's paper shows that any decay in c must be accompanied by comparable changes in other fundamental constants, such as the fine structure constant a. Troitskii points out that such changes would be detectable after only ten years (he assumes that the universe is at least ten billion years old). But if the universe is only ten thousand years old, as young-earth creationists say, the corresponding rates of change in these other fundamental constants would have to be a million times larger than Troitskii assumes. Such large changes would already have been observed, for they are many orders of magnitude larger than the detectability limit. Since they have not been observed, on these grounds alone we can say that Troitskii's paper in no way supports creationist theory and, in fact, contradicts it.
Brown discusses Van Flandern's work on variations in the gravitational constant G. Here there are two points to make. First, dynamical astronomy universally recognize that these observations are very difficult to make and interpret (T. Damour, G. W. Gibbons and J. H. Taylor, "Limits on the Variability of G Using Binary-Pulsar Data," Physical Review Letters, 1988: 61:1151). Although Van Flandern believed that he had detected a very small secular change in G, the consensus of nearly all workers in this field is that Van Flandern's data do not support this conclusion. At best, he has set an upper limit, which means that, to within the measurement accuracy, G does not change (R. D. Reasenberg, "The Constancy of G and Other Gravitational Experiments," Philosophical Transactions of the Royal Society of London, 1983:A310:227-238). The second point is similar to the one I made above in connection with Troitskii's work. Even if we were to accept Van Flandern's value at face value, the rate at which G changed would be extremely small and would only become significant over the ten-billion-year lifespan he presumed for the universe. In order to obtain the change creationists require in only ten thousand years, the rate of change of G would have to be a million times larger than Van Flandern's value. Such a large change is clearly ruled out by observation.
Like many others. Brown speculates on changes in radioactive decay rates. Here again, creationist speculation must contend with some hard facts. Assuming constant decay rates, the radiochronometric data on terrestrial and lunar rocks show convincingly that the solar system is between four and five billion years old. In order for these data to be consistent with young-earth creationism, over the past ten thousand years the decay rates must have averaged five hundred thousand times larger than they are now and the maximum decay rates must have been many orders of magnitude larger than that. Such large decay rates would have been accompanied by a correspondingly large release of energy. If this had happened, the earth would still be molten, and the enormous background radiation would have destroyed most if not all life. Furthermore, as Brown states, a decay in c means that atomic properties would change. What he does not seem to realize is that, for c to have been large enough in the past to support his scenario, atomic properties would have had to have changed very radically indeed. We know that the fundamental constants of physics are so delicately balanced that even very small changes in them would make life impossible (W. H. Press and A. P. Lightman, "Dependence of Macrophysical Constants on the Values of the Fundamental Constants," Philosophical Transactions of the Royal Society of London, 1983:A310: 323-336). Since the creationist c decay theory requires changes in fundamental constants that are many, many orders of magnitude larger than what is permitted, it must be rejected.
Brown discusses the fact that there are more superluminal jets in quasars than naive theory would predict. He says that as a result ''the relativistic explanation is generally rejected." This is absolutely wrong. The apparent excess of superluminal jets is easily explained if quasars are systematically brighter, and hence more readily detected, when their jets are beamed toward us, just as a flashlight is much brighter when pointed directly toward an observer (D. Wills, "Rapid Radio Emissions," Science, 1987:238: 1740). There is convincing evidence that this is the case and that it does indeed explain the observed excess. The generally accepted explanation of superluminal jets is still that it is a relativistic effect (T. J. Pearson and J. A. Zensus in Superluminal Radio Sources, Cambridge University Press, 1987:6; M. H. Cohen, "Radio Sources: Small Scale Structure," in Active Galactic Nuclei, Berlin: Springer-Verlag, 1988:296-300).
Finally, Brown discusses the work of Pappas and Oblensky. Since their work is highly controversial and has not yet been replicated, any conclusions based upon it are purely speculative. At this time, it certainly does not constitute credible evidence for a decay in c.
I thank G. Shields, E. Vishniac, B. Wills, and D. Wills for useful discussions.
-William H. Jefferys