News of the WeekGeochemistry

Tweaking the Clock of Radioactive Decay

+ See all authors and affiliations

Science  29 Oct 1999:
Vol. 286, Issue 5441, pp. 882-883
DOI: 10.1126/science.286.5441.882

You are currently viewing the summary.

View Full Text


Radioactive decay--the pacemaker of geologic time--can no longer be called precisely "clocklike." In the 15 September issue of Earth and Planetary Science Letters, a geochemist reports that the decay rate of beryllium-7 varies, depending on its chemical form. The variations seen so far are much too small, just a percentage or so, to affect Earth's overall time scale. Still, the variability in beryllium decay will prompt those who want to trace out fine divisions in the earliest reaches of time to take a close look at their pacemakers.