Radioactive Decay Rate Variable?

Uncommon Descent calls our attention to this paper which indicates that radioactive decay rates are not constant, but seem to vary with distance from the sun. The assumption that radioactive decay rates are constant is key to the use of radioactive decay as a dating technique. The variations don’t affect the million-to-billion year age estimates obtained by decay rates by very much, but it does indicate a need to research the unknown cause of this variation and evaluate its implications for dating techniques.

Abstract:

Unexplained periodic fluctuations in the decay rates of 32Si and 226Ra have been reported by groups at Brookhaven National Laboratory (32Si), and at the Physikalisch- Technische-Bundesandstalt in Germany (226Ra). We show from an analysis of the raw data in these  experiments that the observed fluctuations are strongly correlated in time, not only with each other, but also with the distance between the Earth and the Sun. Some implications of these results are also discussed, including the suggestion that discrepancies in published half-life determinations for these and other nuclides may be attributable in part to differences in solar activity during the course of the various experiments, or to seasonal variations in fundamental constants.