When the researchers discovered a link between solar flares and the unusual variation of the decay constant of radioactive elements on Earth is playing a scientific research that could end up rewriting some of the laws of physics.
DAN STÖBER
It 'a mystery that occurred unexpectedly: The radioactive decay of some elements in laboratories on Earth seemed to be influenced by solar activity , 150 million kilometers.
How is this possible?
Researchers at the ' University of Stanford and Purdue believe that it is indeed possible. But their explanation of how this can happen is another mystery.
C 'is the possibility that this unexpected effect is caused by an unknown particle emitted by the sun. "It would be really remarkable," said Professor Peter Sturrock of Stanford, an expert in solar physics.
The story begins, in a sense, in classrooms around the world, where students are taught that the rate of decay of a specific radioactive material is constant. This property of radioactive isotopes, is used for example, by anthropologists for dating ancient artifacts with the carbon-14, or when doctors need to calibrate the right dose of radiation to treat cancer patients.
Random Numbers
But the fact that " the rate is constant half-life ", was unexpectedly challenged by a group of researchers at Purdue University who at the time were more interested in finding a good random number generator which to study the nuclear decay of isotopes radioactive. (Scientists use long sequences of random numbers for a series of calculations, but are difficult to produce, because the process used to produce the numbers has an influence on the result).
Ephraim Fischbach, a professor of physics at Purdue, was using the rate of radioactive decay of different isotopes as a possible source of random numbers generated in such a way as not to require any human intervention. (For example, a certain amount of radioactive cesium-137, decays with a rate constant on the whole, but individual atoms within the mass will decay in an unpredictable way, with a random pattern. In this way, the time differences between the "tick" of a random Geiger counter placed near the cesium could be used to generate random numbers.)
Ultimately, the researchers found that the measured decay rates are not in line with published data relating to specific isotopes and this is very strange for alleged physical constants.
By controlling the data collected at Brookhaven National Laboratory on Long Island and the Federal Physical and Technical Institute in Germany, has come up with something even more surprising: the 'long-term observation of the decay rate of silicon-32 and radium-226 seems to show a small seasonal variation.
By controlling the data collected at Brookhaven National Laboratory on Long Island and the Federal Physical and Technical Institute in Germany, has come up with something even more surprising: the 'long-term observation of the decay rate of silicon-32 and radium-226 seems to show a small seasonal variation.
The decay rate was slightly faster in winter than in summer.
This fluctuation is real? Or is just a glitch in the equipment used to measure radioactive decay ... maybe caused by the change of seasons, with accompanying changes in temperature and humidity.
Sturrock has commented on the 'what happened: "We were all convinced that the decay rates were fixed, therefore we thought that they were only experimental errors."
The sun gets to hear.
On 13 December 2006, the sun itself has provided a crucial clue, when a solar flare sent a stream of particles and radiation toward Earth.
Jere Jenkins nuclear engineer of 'Purdue University during the measurement of the decay rate of manganese-54, an isotope with short half-life, which is used in medical diagnostics, noticed that the decay rate dropped slightly during the flare, which is a decrease began about a day and a half before the flare.
If this relationship apparent between flares and decay rates is true, could be used as a method of predicting solar flares before they occur, which could help prevent damage to satellites and power grids, in addition to saving the lives of astronauts in space.
The 'anomaly of the decay rate recorded that night in Indiana, he felt that something produced by the sun, she traveled through space and through the Earth to reach the detectors Jenkins.
What can be issued by the flare to have such an effect?
Jenkins and Fischbach have speculated that the perpetrators of this disorder in the rate of decay were probably solar neutrinos , ghostly particles to almost weightless, and about as fast as the light that can cross the physical world, ie human beings, rocks, oceans and planets with virtually no interaction.
In a series of articles published in Astroparticle Physics, Nuclear Instruments and Methods in Physics Research and Space Science Reviews, Jenkins, Fischbach and their colleagues have shown that hardly any observed changes in decay rates, could come from environmental influences on the detection system.
Reason for suspicion
Their findings reinforce the view that fluctuations in rates of decay caused by neutrinos have been strange from the sun. The decay rates see-saw, seemed to be in harmony with the Earth's elliptical orbit, and these vary as the Earth approaches the Sun (because it was exposed to more neutrinos) and then when it goes away.
So there was good reason to suspect the sun, but it could be proved?
Then help comes from Peter Sturrock of Stanford . During a visit to the National Solar Observatory in Arizona, Sturrock is informed of the discovery made by researchers at Purdue.
Sturrock knew from long experience that the intensity of the bombardment of neutrinos from the Earth varies on a regular basis following the rotation of the sun. His advice to researchers at Purdue: look for evidence that the change in the radioactive decay of the Earth changes with the rotation of the sun. "This is what I suggested. And this is what we did. "
A surprise
By controlling the data on the radioactive decay from Brookhaven Lab, the researchers found a pattern of 33 days. It 'was a surprise, given that most solar observations show a pattern of about 28 days - the rate of rotation of the sun's surface.
The explanation? The core of the sun apparently revolves more slowly than the surface that we see taking place here and is the nuclear reactions that produce neutrinos. "It may seem counterintuitive, but everything suggests that the core rotates more slowly than the rest of the sun," said Sturrock.
All the evidence pointed to an conclusion that the Sun is to "communicate" with radioactive isotopes on Earth, said Fischbach.
But there's a pretty big question remained unanswered. No one knows how neutrinos could interact with radioactive materials and be able to change their rate of decay.
"It makes no sense according to conventional ideas," said Fischbach.Jenkins added: "What we're suggesting is that something that really does not interact with anything is changing something that can not be changed."
Sturrock agrees: "It 'an even inexplicable." "Theorists are beginning to say: 'What's going on?' But that's what the data show. It 'a challenge for physicists and a challenge even for the people of solar energy. "
If the particle is not a mysterious neutrino, "It should be something that we do not know, an unknown particle emitted by the sun that has this effect on radioactive isotopes, and this would be even more remarkable," said Sturrock.
Article written by Chantal Jolagh, "science-writing intern at the Stanford News."
http://terrarealtime.blogspot.com/2011/09/misteriose-particelle-dal-sole-stanno.html
http://terrarealtime.blogspot.com/2011/09/misteriose-particelle-dal-sole-stanno.html
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