Monday, 30 August 2010

Amazing discovery: Solar flares have an effect on radioactive decay

Solar flares can have an effect on radioactive decay. Image courtesy of NASA.

Joel Kontinen

Researchers usually assume that radioactive elements decay at a constant rate although some studies conducted in the past few years (read more here and here) throw a dark cloud over this view.

Last week Stanford University published an intriguing report on the effect of solar flares on the decay of radioactive elements. This new research challenges ingrained beliefs in the reliability of dating methods.

It all began at Purdue University, where a group of researchers was trying to use the decay rate of radioactive isotopes to generate random numbers. They soon found out that the decay rates were not as regular as they had assumed and that there were irregularities in research conducted in the field.

Then they discovered that silicon-32 and radium-226 decay slightly faster in winter than in summer. Peter Sturrock, emeritus professor of applied physics at Stanford University, says: "Everyone thought it must be due to experimental mistakes, because we're all brought up to believe that decay rates are constant."

In December 2006 Jere Jenkins, a nuclear engineer at Purdue University, measured the decay rate of manganese-54 and found out that it dropped slightly about a day and a half before a solar flare.

Jenkins and Ephraim Fischbach, who studies random numbers at Purdue University, concluded that the Sun’s neutrinos have an effect on the decay rate.

Peter Sturrock, who studies ”the inner workings of the sun”, advised them to check previous research results on how the Sun’s rotation had an effect on the decay rate of radioactive elements measured on Earth. They found a clear 33-day cycle.

In other words: isotopes do not decay at a constant rate.

The discoveries at Purdue and Stanford could revolutionise our thinking about dating methods. Faith in millions of years might well weaken once people realise the significance and implications of the research results.

However, the ideological baggage associated with the idea of millions of years might cause some skeptics to reject the new discoveries like they initially refused to believe in the discovery of soft tissue in dinosaurs and carbon-14 in diamonds.


Stober, Jan. 2010. The strange case of solar flares and radioactive elements. Stanford University News. (23 August).