2 Possible link between the changing fine - structure constant and the accelerating universe via scalar - tensor theory

In 1976, Shlyakhter showed that the Sm data from Oklo results in the upper bound on the time-variability of the fine-structure constant: |α̇/α|< ∼10y, which has ever been the most stringent bound. Since the details have never been published, however, we recently re-analyzed the latest data according to Shlyakhter’s recipe. We nearly re-confirmed his result. To be more precise, however, the Sm data gives either an upperbound or an “evidence” for a changing α: α̇/α = −(0.44±0.04)×10−16y−1. A remark is made to a similar re-analysis due to Damour and Dyson. We also compare our result with a recent “evidence” due to Webb et al, obtained from distant QSO’s. We point out a possible connection between this time-dependence and the behavior of a scalar field supposed to be responsible for the acceleration of the universe, also revealed recently. 1 How did constants cease to be constant? More than 60 years ago, Dirac startled the science community by saying that the gravitational constant G is not a true constant, but decays like the inverse of the cosmic time t: G(t) ∼ t, (1) from which follows that the rate of the fractional change Ġ/G should be like Ġ G ∼ −t ∼ −10y, (2) because the present age of the universe is believed to be somewhere around 10y. I do not know how many physicists were really convinced with Dirac’s argument, based on the “Large-numbers Hypothesis.” No matter what philosophy he had started with, however, it is clear that he opened up a new view of looking at the very fundamental aspect of laws of Nature. Some people tried hard to prove or disprove his result. But the number is so small that almost any noise would easily wipe out the real effect if there is any. Delivered at First International ASTROD School and Symposium, September 12-23, 2001, Beijing.