June 27, 2011 - When researchers identified an unusual linkage amongst solar flares and the inner life of radioactive elements on Earth, it touched off a scientific detective investigation that could end up defending the lives of space-walking astronauts and possibly rewriting some of the assumptions of physics.
L.A. Cicero Peter Sturrock, professor emeritus of applied physics
It's a mystery that offered itself unexpectedly: The radioactive decay of some components sitting down quietly in laboratories on Earth
seemed to be motivated by activities inside of the sun, 93 million miles absent.
Is this possible?
Scientists from Stanford and Purdue College imagine it is. But their rationalization of how it transpires opens the door to however another mystery.
There is even an external chance that this unforeseen result is introduced about by a formerly mysterious particle emitted by the sun. "That would be actually outstanding," said Peter Sturrock, Stanford professor emeritus of used physics and an expert on the internal workings of the sun.
The tale begins, in a feeling, in classrooms around the world, in which college students are taught that the price of decay of a certain radioactive substance is a constant. This idea is relied upon, for example, when anthropologists use carbon-14 to date historical artifacts and when physicians determine the suitable dose of radioactivity to deal with a most cancers individual.
But that assumption was challenged in an unforeseen way by a group of scientists from Purdue College who at the time have been far more interested in random figures than nuclear decay. (Experts use long strings of random figures for a assortment of calculations, but they are difficult to create, since the process utilised to create the figures has an influence on the consequence.)
Ephraim Fischbach, a physics professor at Purdue, was searching into the price of radioactive decay of a number of isotopes as a achievable resource of random figures produced with no any human input. (A lump of radioactive cesium-137, for case in point, might decay at a steady charge general, but individual atoms inside the lump will decay in an unpredictable, random pattern. Hence the timing of the random ticks of a Geiger counter
placed in the vicinity of the cesium could be employed to generate
As the scientists pored by way of published info on certain isotopes, they identified disagreement in the measured decay charges – odd for supposed bodily constants.
Checking info collected at Brookhaven National Laboratory
on Long Island
and the Federal Physical and Technical Institute in Germany, they arrived across a thing even much more surprising: long-expression observation of the decay fee of silicon-32 and radium-226 appeared to show a tiny seasonal variation. The decay fee was at any time so marginally more quickly in winter than in summer time.
Was this fluctuation genuine, or was it just a glitch in the equipment utilised to measure the decay, induced by the alter of seasons, with the accompanying changes in temperature and humidity?
"Everyone believed it should be because of to experimental blunders, simply because we're all introduced up to think that decay rates are consistent," Sturrock
The sun speaks
On Dec thirteen, 2006, the sun alone supplied a vital clue, when a solar flare sent a stream of particles and radiation toward Earth. Purdue nuclear engineer Jere Jenkins, although measuring the decay fee of manganese-fifty four, a short-lived isotope utilized in healthcare diagnostics, observed that the rate dropped slightly in the course of the flare, a decrease that commenced about a day and a half just before the flare.