perfidy

Well, this is fascinating. It appears that solar flares have an effect on radioactive decay rates here on Earth:

On Dec 13, 2006, a solar flare sent a stream of particles and radiation toward Earth. Purdue nuclear engineer Jere Jenkins, while measuring the decay rate of manganese-54, a short-lived isotope used in medical diagnostics, noticed that the rate dropped slightly during the flare, a decrease that started about a day and a half before the flare.

Long-term observation of the decay rate of silicon-32 and radium-226 seemed to show a small seasonal variation. The decay rate was ever so slightly faster in winter than in summer.

If this apparent relationship between flares and decay rates proves true, it could lead to a method of predicting solar flares prior to their occurrence, which could help prevent damage to satellites and electric grids, as well as save the lives of astronauts in space.

All well and good - flare warnings would be of great benefit. But it seems to me that the article is missing something very important: if radioactive decay rates here on Earth are subject to variation based on electromagnetic activity from the Sun, what does that mean for all our radiometric dating techniques? The Carrington Event back in 1859 was orders of magnitude more powerful than the flare in '06. The Sun was quiescent for centuries in the Little Ice Age. What other changes in our electromagnetic environment have occurred in the past 50000 years? If they were strong enough, they could have a significant effect on the calculated age of archaeological finds.

Also, I remember being taught that radioactive decay was a constant.  Why was I lied to?  Or is this really that ground shaking a discovery?

In other Sun news,

• Solar cycles have been detected in another star. They're much shorter than ours, though, less than a year. Interesting.
• Shocking news:  "Large changes in the sun's energy output may drive unexpectedly dramatic fluctuations in Earth's outer atmosphere."  You think?  Why would that be unexpected?  Or is it unexpected like each month's unemployment numbers?
• And, bonus vaguely sun-related link: Bull-killer, Sun Lord, about Mithraism in the Early Roman Empire.  I think my neighbor is a Mithraist.  He was in the army, and he doesn't like the Chicago Bulls.