The strange case of solar flares and radioactive elements
August 23, 2010 | 11:50 am
Peter Sturrock, Stanford professor emeritus of applied physics. Photo by L.A. Cicero
This story is from the Aug. 23, 2010 issue of Stanford Report.
When researchers found an unusual linkage between solar flares and the inner life of radioactive elements on Earth, it touched off a scientific detective investigation that could end up protecting the lives of space-walking astronauts and maybe rewriting some of the assumptions of physics.
It’s a mystery that presented itself unexpectedly: The radioactive decay of some elements sitting quietly in laboratories on Earth seemed to be influenced by activities inside the sun, 93 million miles away.
Is this possible?
Researchers from Stanford and Purdue universities believe it is. But their explanation of how it happens opens the door to yet another mystery.
There is even an outside chance that this unexpected effect is brought about by a previously unknown particle emitted by the sun. “That would be truly remarkable,” said Peter Sturrock, Stanford professor emeritus of applied physics and an expert on the inner workings of the sun.
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 a constant. This concept is relied upon, for example, when anthropologists use carbon-14 to date ancient artifacts and when doctors determine the proper dose of radioactivity to treat a cancer patient.
Random numbers
But that assumption was challenged in an unexpected way by a group of researchers from Purdue University who at the time were more interested in random numbers than nuclear decay. (Scientists use long strings of random numbers for a variety of calculations, but they are difficult to produce, since the process used to produce the numbers has an influence on the outcome.)
Ephraim Fischbach, a physics professor at Purdue, was looking into the rate of radioactive decay of several isotopes as a possible source of random numbers generated without any human input. (A lump of radioactive cesium-137, for example, may decay at a steady rate overall, but individual atoms within the lump will decay in an unpredictable, random pattern. Thus the timing of the random ticks of a Geiger counter placed near the cesium might be used to generate random numbers.)
As the researchers pored through published data on specific isotopes, they found disagreement in the measured decay rates – odd for supposed physical constants.
Checking data collected at Brookhaven National Laboratory on Long Island and the Federal Physical and Technical Institute in Germany, they came across something even more surprising: 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.
Was this fluctuation real, or was it merely a glitch in the equipment used to measure the decay, induced by the change of seasons, with the accompanying changes in temperature and humidity?
“Everyone thought it must be due to experimental mistakes, because we’re all brought up to believe that decay rates are constant,” Sturrock said.
The sun speaks
On Dec 13, 2006, the sun itself provided a crucial clue, when 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.
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.
The decay-rate aberrations that Jenkins noticed occurred during the middle of the night in Indiana – meaning that something produced by the sun had traveled all the way through the Earth to reach Jenkins’ detectors. What could the flare send forth that could have such an effect?
Jenkins and Fischbach guessed that the culprits in this bit of decay-rate mischief were probably solar neutrinos, the almost massless particles famous for flying at nearly the speed of light through the physical world – humans, rocks, oceans or planets – with virtually no interaction with anything.
Then, in a series of papers published in Astroparticle Physics, Nuclear Instruments and Methods in Physics Research and Space Science Reviews, Jenkins, Fischbach and their colleagues showed that the observed variations in decay rates were highly unlikely to have come from environmental influences on the detection systems.
Reason for suspicion
Their findings strengthened the argument that the strange swings in decay rates were caused by neutrinos from the sun. The swings seemed to be in synch with the Earth’s elliptical orbit, with the decay rates oscillating as the Earth came closer to the sun (where it would be exposed to more neutrinos) and then moving away.
So there was good reason to suspect the sun, but could it be proved?
Enter Peter Sturrock, Stanford professor emeritus of applied physics and an expert on the inner workings of the sun. While on a visit to the National Solar Observatory in Arizona, Sturrock was handed copies of the scientific journal articles written by the Purdue researchers.
Sturrock knew from long experience that the intensity of the barrage of neutrinos the sun continuously sends racing toward Earth varies on a regular basis as the sun itself revolves and shows a different face, like a slower version of the revolving light on a police car. His advice to Purdue: Look for evidence that the changes in radioactive decay on Earth vary with the rotation of the sun. “That’s what I suggested. And that’s what we have done.”
A surprise
Going back to take another look at the decay data from the Brookhaven lab, the researchers found a recurring pattern of 33 days. It was a bit of a surprise, given that most solar observations show a pattern of about 28 days – the rotation rate of the surface of the sun.
The explanation? The core of the sun – where nuclear reactions produce neutrinos – apparently spins more slowly than the surface we see. “It may seem counter-intuitive, but it looks as if the core rotates more slowly than the rest of the sun,” Sturrock said.
All of the evidence points toward a conclusion that the sun is “communicating” with radioactive isotopes on Earth, said Fischbach.
But there’s one rather large question left unanswered. No one knows how neutrinos could interact with radioactive materials to change their rate of decay.
“It doesn’t make sense according to conventional ideas,” Fischbach said. Jenkins whimsically added, “What we’re suggesting is that something that doesn’t really interact with anything is changing something that can’t be changed.”
“It’s an effect that no one yet understands,” agreed Sturrock. “Theorists are starting to say, ‘What’s going on?’ But that’s what the evidence points to. It’s a challenge for the physicists and a challenge for the solar people too.”
If the mystery particle is not a neutrino, “It would have to be something we don’t know about, an unknown particle that is also emitted by the sun and has this effect, and that would be even more remarkable,” Sturrock said.
– by Dan Stober with contributions from Chantal Jolagh, a science-writing intern at the Stanford News Service.
Press Release
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34 Comments »
August 23rd, 2010 at 2:37 pm
the almost weightless particles famous for flying at the speed of light through the physical world
It’s quite shocking to see articles with a statement such as the one quoted above being posted on “a joint Fermilab/SLAC publication.”
August 23rd, 2010 at 3:57 pm
@Navneeth: You are quite correct that that statement is in error. This press release was picked up “as is” from the source, but we have corrected the statement in the text to make it accurate.
One of the big questions in physics is just how close to the speed of light do neutrinos tend to travel at. Until physicists know what their mass is, we won’t know for sure. All physicists know right now is that the mass is extremely small and the speed of neutrinos is close enough to the speed of light that they haven’t been able to distinguish those speeds as different in a solid quantifiable way. However, we do know that the speed of at least some of the neutrinos must be less than the speed of light.
August 23rd, 2010 at 7:34 pm
is it possible that these particles are entangled, and have been since their creation (by solar processes)?
August 24th, 2010 at 7:54 am
What are the possible implications of this discovery for radioactive dating?
August 24th, 2010 at 1:04 pm
Anyone with the equipment to measure radioactive decay should be able to test this for themselves.
There was one rather blatant omission from this article though…
HOW MUCH variation should we expect to see?
August 24th, 2010 at 1:56 pm
Does this in any way affect technologies that rely on decay? For example, since Carbon-14 & K–Ar dating rely on a constant rate of decay, do we know how much variance is this effect introducing?
August 24th, 2010 at 7:25 pm
@kevin: It depends on which particles you are talking about. If two neutrinos are emitted in one reaction, then it is actually quite likely that they are entangled. Whether that entanglement survives is another question. A big problem is that physicists aren’t able to measure the spin orientation of neutrinos to check such a thing.
If you are wondering whether that entanglement between something in the Sun and a neutrino interacting with a decaying nucleus on Earth could affect that decay rate, then the answer will be no, I think. It is hard to imagine a scenario where such a type of entanglement would create a mechanism to change decay rates. Somebody more knowledgeable about neutrino physics could answer this better than I could though!
August 25th, 2010 at 7:03 am
@Maria: Concerning radioactive dating, it would seem that it might have a very slight effect so as to mean that whatever is being dated is actually marginally older than the dating would indicate. It does depend on the rate of decay rate used. Is it an average decay rate that takes into account the variations in rate (no change)? Is it the greater decay rate or the lower decay rate ((older or younger, respectively)?
August 25th, 2010 at 7:13 am
If someone here has the data, could you post some numbers: I’d like to know the numerical difference in decay rates between the seasons. eg, 1% faster decay in winter than in summer, 0.1%? 0.01%??
And the % drop before the solar flare too would be nice.
August 25th, 2010 at 11:17 am
So when the big bang happened was this decay rate accelerated or decreased during the period of time when the planets and stars were forming. Is it impossible for neutrinos to exist before stars formed? How much evidence do we have that neutrinos have been emitted at a constant rate from our sun over the billions of years it has been operating?
August 26th, 2010 at 12:33 am
Papers:
Perturbation of nuclear decay rates during the solar flare of 2006 December 13
http://dx.doi.org/10.1016/j.astropartphys.2009.04.005
Evidence of correlations between nuclear decay rates and Earth–Sun distance
http://dx.doi.org/10.1016/j.astropartphys.2009.05.004
In particular, see this graph for an explanation of the rates:
http://www.sciencedirect.com/science?_ob=MiamiCaptionURL&_method=retrieve&_udi=B6TJ1-4WDGCNK-1&_image=fig1&_ba=1&_user=4420&_coverDate=08%2F31%2F2009&_alid=1441903185&_rdoc=1&_fmt=full&_orig=search&_cdi=5297&_issn=09276505&_pii=S092765050900084X&view=c&_acct=C000059607&_version=1&_urlVersion=0&_userid=4420&md5=3d9cea58f6a7c0f05dcf360a29dabe08
August 26th, 2010 at 10:45 am
How much variation? Here is a press article that mentions a seasonal variation of 0.37 percent.
http://www.examiner.com/creationism-in-national/radioactivity-might-not-be-constant-after-all
Heh, I didn’t know the National Examiner did this, but that’s the best article on the subject I’ve read so far… I thought they mostly talked about tabloidy stuff.
August 26th, 2010 at 6:01 pm
Any ideas about the ~2month phase shift(delay) between distance change and decay rate change what is obvious from
the graph mentioned before
http://www.sciencedirect.com/science?_ob=MiamiCaptionURL&_method=retrieve&_udi=B6TJ1-4WDGCNK-1&_image=fig1&_ba=1&_user=4420&_coverDate=08%2F31%2F2009&_alid=1441903185&_rdoc=1&_fmt=full&_orig=search&_cdi=5297&_issn=09276505&_pii=S092765050900084X&view=c&_acct=C000059607&_version=1&_urlVersion=0&_userid=4420&md5=3d9cea58f6a7c0f05dcf360a29dabe08
August 27th, 2010 at 7:06 am
There is also another news strongly suggesting that we should revise nuclear physics:
http://www.physorg.com/news202020721.html
So maybe they are not just blurry, fluctuating as in QM picture, but rather have some concrete spatial structure near (local?) energy minimum? (analogously to protein folding)
These energy minimas can have different shape – depth, width – and so different statistical dependence on energy carriers like Sun’s neutrinos – comparing such behavior of different isotopes could became the basic tool to finally understand the structure of nucleuses …
August 27th, 2010 at 5:47 pm
Fischbach has been looking for anomalous forces for some time now (http://prl.aps.org/abstract/PRL/v56/i22/p2425_1), and the probability of a systematic effect generating an annual cycle seems high to me: i.e., there may be no real variation whatsoever. As for the creationists, an oscillatory 0.25 % amplitude effect will get them nothing.
August 30th, 2010 at 9:28 am
I cannot believe that neutrinos are the cause of the fluctuations. Neutrino scattering cross sections are so miniscule that it just cannot be the source of the fluctuation in decay rates. Without seeing the data first hand, count me as a giant skeptic.
August 30th, 2010 at 12:13 pm
Maybe the decay rate is still constant but the time/space is being changed as a result of the gravity change of the sun generating slow gravity wave slowing and speeding up the time while the decay rate remains constant. The closer we are to the sun the slower time will pass. We would not notice because it’s all relative. Time passage in the core of the sun moves slower due to it greater denseness. Thus being 33 days verses 28 days. Solar flares are also are very great masses of matter being separated from the sun very rapidly. This may generate wave of gravity that changes the space time. I have not done the math just throwing a quite ideal out there.
August 30th, 2010 at 1:23 pm
@Tony,
“Does this in any way affect technologies that rely on decay? For example, since Carbon-14 & K–Ar dating rely on a constant rate of decay, do we know how much variance is this effect introducing?”
Since carbon dating is used to obtain approximate age, I don’t see any changes.
The rate of decay used (if my memory is correct) is a long-term average. Also, the results have always had a margin of error built in, so the dating technologies will remain the same.
August 30th, 2010 at 6:50 pm
The Carbon-14 scale is already calibrated against other sources, such as tree rings and sediment beds. It has to be, because the ratio of C-14 to C-12 in the atmosphere hasn’t been constant. If not only the environmental ratio, but also the rate of decay has changed, that would just mean that the reasons for the tweaks in the C-14 scale are different than we thought they were. But the overall calibrated scale would still stand as-is.
August 30th, 2010 at 7:55 pm
now that gravity is brought in, the natural question arises – before bringing in neutrinos, has the effect of gravitational time dilation been factored in?
It sounds like not only decay may be affected – for example, it would be interesting to compare frequencines in the
http://en.wikipedia.org/wiki/Pound%E2%80%93Rebka_experiment or any other experiment touching on QM fundamentals when
run at the perihelion and aphelion of the Earth orbit.
August 31st, 2010 at 10:53 am
Per this article in Nature, 2000, the quantum anti-zeno effect has been experimentally verified to increase the rate of radioactive decay: “Acceleration of quantum decay processes by frequent observations”:
http://www.nature.com/nature/journal/v405/n6786/abs/405546a0.html
So, if neutrinos “observe” atomic nuclei, and the rate of neutrino observations changes appreciably, it isn’t a huge leap to assume that the rate of radioactive decay can change as a result of the quantum (anti) zeno effect. For this to occur, neutrinos don’t have to interact with atomic nuclei to such a degree that an electron, positron or muon is generated. The interaction only has to consist of a “measurement”.
September 1st, 2010 at 10:45 am
I think nobody will read this one but I try. If the graph is correctly phased seems that the decay oscillation is in sync with the equinoxes rather than with the distance from the sun (especially because the distance in the reality vary in an asymmetric way, due to the elliptic orbit; probably the distance dependence is present but smaller). This would imply that the effect of the sun is mainly due to direct radiation. Anyway testing all the hypothesis is quite simple, it’s enough to test the decay rate during the same period of the year in different latitude places. Moreover, testing the neutrino hypothesis is even easier, in fact experiments using neutrino flux generated by accelerators are quite common, if (and I do not know) the flux density is higher then the sun one, would be easy to determinate any kind of influence.
Independently from the answer, is amazing that still today exists such a strange phenomenon. Physic still have a lot (a lot) to verify before to think at GUT and such things
September 1st, 2010 at 10:37 pm
Something seems conceptually screwy about this article and some of the quotes. Throughout, “rate of decay” is described as something that was historically thought to be constant. But when we talk about radioactive decay being a constant, that could only have meant spontaneous decay. After all, there are nuclear reactors and nuclear weapons, and the way they function is by accelerating the rate of radioactive decay. Or am I misunderstanding something? Is the process of decay into more stable atomic isotopes not called radioactive decay whenever it is being caused by energetic particles from nearby atoms?
Regardless of terminology, this research, if it holds up, does point in an interesting direction. It suggests that nothing we have measured thus far as a rate of decay is spontaneous in the sense of not being influenced by external energetic particles. And so no such rate we have measured thus far is a universal constant. Instead, these are Earth-specific values of decay under conditions that have persisted here.
One way to try to resolve this is to look for a truly spontaneous rate of decay, without any influence by forces outside the atom including neutrinos. But is that a feasible project? Another approach is to somehow define a standard the background intensity of neutrinos and set decay rates accordingly.
Others have pointed out that radiocarbon dating has been calibrated against tree rings and sediment layers. For dating in the last million years or so, I’d guess that is able to give enough support not to worry. But what about events dated 500 million or a billion years ago? Is there enough external calibration that we can be sure our dates aren’t off quite a lot if the sun has kicked out neutrinos at different rates over its lifetime? (not within years, but across years)
I’m sure it’s obvious that I’m a layperson and not a physicist, geologist, or archeologist. I welcome being disabused of any misconceptions.
September 2nd, 2010 at 3:06 pm
It’s not evident to me that entanglement has been dismissed as a explanation for this result (and quite a few others in the journals lately, too). I don’t think we yet grasp the implications of QCD, but it is possible that the models we have set up to analyze this data are enough “off” to produce a result like this. I am starting to suspect that the nullification of gravity is next! Really, all the fundamental ‘laws’ are starting to look weird…
September 5th, 2010 at 9:55 am
This may be a crude way to poke at the problem, but I am wondering if you could use one of the existing beams of artificially-generated neutrinos to test the effect. (Perhaps the main injector for Fermi Lab’s MINOS experiment) Couldn’t you put a radioactive sample with a detector and place it in the beam line?
November 4th, 2010 at 2:57 pm
The effect of perturbation of nuclear decay rates during the solar flare is very doubtful.
A.G. Parkhomov. Effect of radioactivity decrease. Is there a link with solar flares? arXiv:1006.2295v1
November 17th, 2010 at 11:57 pm
They should be measuring vacuum permittivity at the same place and time they are measuring everything else.
November 26th, 2010 at 7:39 pm
I suppose beta decay, which is thought to depend on slow energy loss until it finally occurs and gives up a neutrino as a part of its mechanism, “if” enough atoms were exposed to a dense enough high energy neutrino stream, you might have the higher energy neutrinos replacing the lower energy ones and changing the decay rate slightly.
January 17th, 2011 at 2:59 pm
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January 28th, 2011 at 4:22 am
DOE trivia: Radiation can actually be adjusted by proximity to Sagittarius A (compensating for red shift, and variation in Black Holar radiation due to a rotational period of 28 days)
January 28th, 2011 at 4:53 am
sorry, rotational period of 33 days.
April 9th, 2011 at 10:39 pm
Would it be possible to send a small “probe” away from the Earth/Sun, with a lump of radioactive material and a beta detector inside. Measure if there is a variation as the “probe” zips away.
One big question though. If a neutrino flux actually help heavy atoms keep their stability, then what happens to non-radioactive heavy atoms when they’re far away from stars? For example, will lead start to decay when not “fed” by neutrinos? Will bismuth atoms start breaking up faster?
August 10th, 2011 at 1:51 am
My explanation for this has been that it is not neutrinos but the aether which flows out from the sun.
Elementary particles may be vortices through which the aether drains into wherever it goes. When this flow is stronger, it binds nuclei together more strongly, very slightly, but enough to alter the entropy of radioisotopes. This may be a modulation of what we call the strong force.
The article may just be describing for the first time experiments which are actually sensitive to the existence of a material aether.
If you look at a closeup of a sunspot, you can see what could be the effect of aether blowing out a hole between the corpuscles.
Unfortunately I suspect I do need to remind readers that the existence of the aether has never been disproven. Rather, since nobody could figure out any way to verify its presence or absence, the existence of an undetectable aether was deemed irrelevant and scientists ceased talking about it, as if its existence were disproven. Perhaps some rethinking of the prevailing aetherless paradigm is in order. Without an aether, photons are waves without any transmission medium – which is of course, no small paradox.
August 27th, 2011 at 3:37 am
hi
i search about which mineral or material in the earth suface and in our environment are release Radon Gaz
I don`t know any thing
can you help me.
tnx
Mostafa Mirhoseini