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The Strange Case of Solar Flares and Radioactive Decay Rates 408

Posted by Soulskill
from the cool-science dept.
DarkKnightRadick writes "Current models for radioactive decay have been challenged by, of all sources, the sun. According to the article, '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.' This is important because the rate of decay is very important not just for antique dating, but also for cancer treatment, time keeping, and the generation of random numbers. This isn't a one time measurement, either. '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.'"
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The Strange Case of Solar Flares and Radioactive Decay Rates

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  • by trip11 (160832) on Tuesday August 24, 2010 @12:11AM (#33350768) Homepage
    I read the article (yes yes I know). But in summary, your hypothesis (temperature fluctations0 was what everyone thought, but the groundbreaking bit was that they did an experiment that provides a LOT of evidence to the contrary.

    The sun has a cycle of it's own (about 1 month). They did a much more accurate study and found the decay rate is tightly correlated to the sun's cycle.

    Longer version:
    The theory now is that it has to do with the neutrino flux. As we move further from the sun the flux goes down by 1/R^2. We saw that fluctuation first. But the neutrino flux also varies with the solar cycle which is independent of the earth's temperature.

    This is very very cool experimental physics. Kudo's to them!

  • by MichaelSmith (789609) on Tuesday August 24, 2010 @12:19AM (#33350808) Homepage Journal

    Its a bit like correlating car crashes with the movement of galaxies. Atoms are tough little beasts and not really affected by anything other than other particles.

  • by Daniel Dvorkin (106857) * on Tuesday August 24, 2010 @12:26AM (#33350848) Homepage Journal

    I don't think anyone really believes the earth is 6000 years old.
    Just that Adam lived 6000 years ago.

    Nope, there are plenty of people around who believe that the days referred to in Genesis are literal days, that Adam was around less than a week after the Earth itself, and that all of this happened six-millennia-and-change ago. They even have a shiny web site where they explain everything.

    http://www.answersingenesis.org/get-answers#/topic/age-of-the-earth [answersingenesis.org]

    Don't underestimate these people. They're loons, but they're well-organized and numerous loons.

  • by Sarten-X (1102295) on Tuesday August 24, 2010 @12:27AM (#33350852) Homepage
    Not quite. Cooper found no variation with regards to one specific isotope of plutonium. There could be a different mechanism at work to cause plutonium's decay, or multiple mechanisms. Maybe neutrinos are involved. Maybe not. The ideas presented in TFA are theories, which will (hopefully) eventually lead to a testable hypothesis.A single contradictory result, without explanation, should not be enough to halt research in the field.
  • Re:Earth Date (Score:4, Informative)

    by AJWM (19027) on Tuesday August 24, 2010 @12:51AM (#33351008) Homepage

    Except that closer analysis of the Si-32 data from Brookhaven also showed a 33-day cycle correlating to the rotation of the Sun's core.

  • More info (Score:3, Informative)

    by PinkyGigglebrain (730753) on Tuesday August 24, 2010 @12:51AM (#33351010)
    Found another article from 2008 [astroengine.com] that postulates that the Earth/Sun distance may also have an effect on isotope decay rates.

    There was also some "fringe" claims back in the early 1990's about how high voltage electrical fields affect alpha decay in isotopes. A quick search turned up a patent [freepatentsonline.com].

    If these claims are substantiated its going to hit more fields than we expect. IIRCC current theory's relating to atomic decay, both classic and quantum, state that the decay rate of unstable atoms is totally random and does not change under any normal conditions. This finding would seem to dispute that, even raising the possibility of accelerating the decay of radioactive atoms into stable one. Might be a way of dealing with the nuclear waste issues if its true and we can figure out how to induce it in the lab. Who knows, once we understand it we might be able to make the effect go the other way and create useful isotopes without needing a reactor.

    No mater the case this is interesting. I'm looking forward to seeing more research on this.
  • by the_womble (580291) on Tuesday August 24, 2010 @12:58AM (#33351056) Homepage Journal

    I have doubts about how numerous they are: being vocal and media savvy can make a group seem much larger than it is.

    Also remember that they are largely restricted to the US and the Middle East.

  • by finarfinjge (612748) on Tuesday August 24, 2010 @01:05AM (#33351096)
    Please don't 'help' the fight to bring some balance to the AGW debate. And to answer your question. Almost certainly not.

    What you are discussing is one of many so called proxies. Don't know what "proxy" means in that connotation, as a thermometer meets that definition. It too is a proxy for measuring temperature. Why not just say thermometers?
    Anyway.
    Radioisotopes are one means of estimating temperature. There are others. Some more robust than others. In the area of skeptical science, versus unskeptical science, you will find that the more informed the debater, the more subtle the argument.

    Let the mod wars begin

    JE
  • by rve (4436) on Tuesday August 24, 2010 @01:11AM (#33351136)

    Also remember that they are largely restricted to the US and the Middle East.

    Bullpoopie. Such ideas have similar prevalence here in protestant parts of Western Europe. Evangelicals are just not as organized politically, and civilians don't have a way of influencing the curriculum of schools, so it's not a high profile issue.

    In Catholic tradition, it's not as common to think of the bible as the literal word of God, so it's less of an issue.

  • by camperdave (969942) on Tuesday August 24, 2010 @01:14AM (#33351162) Journal
    Neutrino density is not going to vary a lot by hemisphere because the planet is fairly transparent to neutrinos. However, the Earth as a whole (including the southern hemisphere) is some 3% closer to the sun during the winter (January) than during the summer.
  • by eleuthero (812560) on Tuesday August 24, 2010 @01:16AM (#33351166)
    Fortunately or unfortunately, depending on your side of the debate, this is not the case.

    http://www.gallup.com/poll/27847/majority-republicans-doubt-theory-evolution.aspx [gallup.com]

    while the title of the article focuses on Republicans, it goes on to discuss Americans in general. Fully 66% of the country holds to some form of a young creationist perspective for humanity (strangely combined with a more even distribution of views on evolution and an old planet/universe. If anything, by these numbers, which appear to hold up in other surveys, the evolutionary system appears to be the vocal minority's position. Within the survey, 38% held to a theistic evolution-esque model.
  • by Gorimek (61128) on Tuesday August 24, 2010 @01:18AM (#33351180) Homepage

    Quote from the article "The principle of operation of an atomic clock is not based on nuclear physics, but rather on the microwave signal that electrons in atoms emit when they change energy levels."

  • Re:Artifact? (Score:3, Informative)

    by PinkyGigglebrain (730753) on Tuesday August 24, 2010 @02:23AM (#33351504)
    Earths distance from the sun isn't constant. On Winter Solstice (Northern Hemi) the Earth is closer to the Sun than the Summer Solstice (Northern Hemi). Being closer Solar effects like the Neutrino flux would be more intense.
  • by Anonymous Coward on Tuesday August 24, 2010 @02:30AM (#33351558)

    Kudo's to them!

    Kudos is not a plural, so no need for the apostrophe.

  • by Anonymous Coward on Tuesday August 24, 2010 @04:15AM (#33352168)

    Sorry, I disagree.

    I grew up in a strongly Anglican school and my mother is a devout catholic. We went to church *every* Sunday until I left home at 20. This was in London and Brighton, England.
    I don't remember ever meeting *anyone* who honestly believed the literal interpretation of the Bible (the 6000 years old, all created by the Old Man in a week stuff).

    I've lived in Belgium, France and now, Germany. Same goes for those countries. And I've met LOTS of Christians, practising and non-practising in my time.

    Evangelicals + Pentecostalists, that's a different matter. But they're not mainstream over here.

  • by rve (4436) on Tuesday August 24, 2010 @04:53AM (#33352342)

    Anecdotal evidence can be deceptive, I was somewhat surprised to read about it too:

    http://www.sciencemag.org/cgi/data/313/5788/765/DC1/1 [sciencemag.org]

    http://www.guardian.co.uk/science/2009/feb/01/evolution-darwin-survey-creationism [guardian.co.uk]

    In another article, not available in English, the numbers were broken down by denomination. Catholics were less likely to take the bible literally, which brings the percentage of creationists down in Germany and the Netherlands, which are both about half catholic, half protestant/none/other

  • by jfb2252 (1172123) on Tuesday August 24, 2010 @06:03AM (#33352682)

    The astroengine article has a graph from the Jenkins 2008 paper http://arxiv.org/abs/0808.3283 [arxiv.org]

    The graph shows variations of order 0.1%. A +-3% seasonal change in orbital radius would give a 6% change in R^2 so the effect is about 1/30 of the effect of the radius change. A change in radius to 1.6 AU should cause a drop to 40% of "solar particle" flux hence about 1.3% change in radioactive heat and thus RTG output, or about 10W. The power output measurement appears to have sufficient precision to show such a drop. Cooper does a much better job than I have with these back of the envelope estimates.

    Coopers paper is http://arxiv.org/abs/0809.4248 [arxiv.org]

    Definitely a puzzle nuclear physicists should be looking at.

  • Re:More info (Score:3, Informative)

    by sFurbo (1361249) on Tuesday August 24, 2010 @06:54AM (#33352888)

    IIRCC current theory's relating to atomic decay, both classic and quantum, state that the decay rate of unstable atoms is totally random and does not change under any normal conditions.

    Not quite, k-electron capture are affected by the cross section of the k-electrons with the nucleus, which might be slightly changed by pressure or chemical bonds. This can lead to a change of up to 1%. The fully ionised nucleus would be stable if there is no other decays possible.

    Other decay modes should also be affected, as the energy levels of the nucleus is pertubed by the electron-density, but this would be a much smaller effect, as the electron cloud is not directly involved in these decays.

  • Decades Old News (Score:3, Informative)

    by b4upoo (166390) on Tuesday August 24, 2010 @07:40AM (#33353162)

    If we went clear back to 1965 you could attend college classes in astronomy that included the teaching that the sun could not produce as much energy as it does with nuclear reactions without having too short a life span. The calculations of that era suggested that gravity was the most likely source of solar heat generation.

  • by realityimpaired (1668397) on Tuesday August 24, 2010 @07:40AM (#33353166)

    There is some genetic evidence to suggest that at one point, we're all descended from a group of about 40 individuals in Africa, mostly from mitochondrial DNA... my guess is that this is way way before 6000 years ago, though... according to eastern legend/history, the Japanese language is about 10,000 years old, and the Chinese culture goes back about as far.

    Not that I'm a creationist or anything, but I think the problem with their 6000 year interpretation is that the oral tradition tends to lose sense of time. While the Bible is written down, I'd lay odds that a great many of the books/stories therein started out as oral tradition and were written down when a system of writing was developed. It can be trusted as allegory, since that's all the books really are, but it's definitely not trustworthy as a literal historical source.

  • by mpe (36238) on Tuesday August 24, 2010 @07:47AM (#33353206)
    If anything, it sounds like our estimates of the Earth's age may be too young, not too old.

    Not just the Earth, but anything where radioactive decay is used as the basis for working out age. Things get even more troublesome if this effect is not uniform across radio isotopes.
  • by ShadowRangerRIT (1301549) on Tuesday August 24, 2010 @08:55AM (#33353702)
    If the Earth's rotation were so slow that millions of years could pass in a "day", then the Earth would have been half frozen and half cooked all the time, with a narrow, possibly habitable zone at the meeting point. That sort of thing would show up quite clearly in the archaeological record. Beyond that, there is no natural mechanism I'm aware of that could impart the necessary rotational energy to said slowly spinning Earth that wouldn't also tear it apart in the process (presumably a sufficiently large thruster running for incredible lengths of time might do it, but that would be tricky to do, since said thruster would need fuel, and would be frozen or melting most of the time).
  • by Mt._Honkey (514673) on Tuesday August 24, 2010 @09:03AM (#33353784)
    Yes, and the difference in isotope is very important here. Si-32 is a beta emitter, which is the type of decay that one might possibly expect to be affected by neutrinos if they had any effect at all, because neutrinos are emitted along with the beta. Ra-226 and Pu-238 are both alpha emitters, which makes the seasonal variation in Ra-226 even stranger because neutrinos are not involved at all in alpha decay.
  • by ShakaUVM (157947) on Tuesday August 24, 2010 @09:50AM (#33354342) Homepage Journal

    >>Jesus spoke about the literalness of the historical record of the Old Testament, and repeatedly throughout the Bible itself is the historicity of the creation account referred-to.

    In the sense that God was the creator of the universe, sure. But the ancient Israelites had a very different conception of "history" than we do. Heroditus hadn't even been born when the early books of the Bible were written. Just as modern people have trouble dealing with the laws in the Old Testament sometimes, because they are structured differently from the more precise laws of today. So the debate is over if the account is a spiritual narrative or a historical narrative. Nachmanides and Maimonides both consider it spiritual narrative, and they often were at different ends of the spectrum from each other.

    Various quotes -

    Colossians 1:15: "He is the image of the invisible God, the firstborn over all creation. For by him all things were created: things in heaven and on earth, visible and invisible, whether thrones or powers or rulers or authorities; all things were created by him and for him. He is before all things, and in him all things hold together."

    Matthew 19:4: ""Haven't you read," he replied, "that at the beginning the Creator 'made them male and female,'"

    Or: "...At the briefest instant following creation all the matter of the universe was concentrated in a very small place, no larger than a grain of mustard. The matter at this time was very thin, so intangible, that it did not have real substance. It did have, however, a potential to gain substance and form and to become tangible matter. From the initial concentration of this intangible substance in its minute location, the substance expanded, expanding the universe as it did so. As the expansion progressed, a change in the substance occurred. This initially thin noncorporeal substance took on the tangible aspects of matter as we know it. From this initial act of creation, from this etherieally thin pseudosubstance, everything that has existed, or will ever exist, was, is, and will be formed." -Nachmanides, ~1250AD

  • by dtjohnson (102237) on Tuesday August 24, 2010 @09:55AM (#33354446)

    In Catholic tradition, it's not as common to think of the bible as the literal word of God, so it's less of an issue.

    Catholics ALWAYS think of the bible as the Word of God. From the 'Catechism of the Catholic Church' No. 81: "Sacred Scripture is the speech of God as it is put down in writing under the breath of the Holy Spirit."

    Getting back to the TFA however, it is possible that the radioactive decay rate is influenced by solar magnetic activity, just as it also seems possible that the solar magnetic field contributes to the source of heat at the center of the Earth. We know very little at the moment about the source of solar magnetism, its strength, and its effects.

  • by radtea (464814) on Tuesday August 24, 2010 @10:10AM (#33354658)

    The link didn't mention a lower bound for the detection sensitivity based on looking at Cassini power outputs.

    The arxiv.org link at the bottom of the article provides just that. The variation in counting (not decay) rates observed is about 0.1% over the 3% variation in Earth's orbital distance, implying about (3E-2)/R**2 as the relationship, and the Cassini results put an upper limit on of less than (0.84E-4)/R**2 and comparable for a /R term.

    Ergo, the Cassini results put on a limit that is more than two orders of magnitude smaller than the original observation. Ergo, the original observation is not due to simply radial distance from the sun, by the perfectly ordinary standards of proof that we use every day.

    That is, there might be some bizzare confounding effect, but I wouldn't bet my next mortgage payment on it. Would you?

  • by chrb (1083577) on Tuesday August 24, 2010 @11:41AM (#33356090)

    If you can measure three significant digits, and your effect is in the fifth, then you do not see it. However a more precise measuring apparatus may measure up to six significant digits, and there the effect may become visible.

    Only when the effect becomes visible you can start saying anything about statistical significance

    This is not true. By collecting many replicates a distribution can be modelled with an estimated mean possessing an accuracy greater than the possible measurement precision of an individual replicate.

    Let's say you have two distributions - one centered at 4.1 and one at 4.4. Standard deviation of both distributions is 1. Your measuring equipment only has an integer resolution. About 95% of samples will have a value that is +/-2 of the true mean. So you will end up with many samples of values, predominantly ...2,3,4,5,6,7... By analysing the distribution of these samples you can derive confidence intervals for the sample mean, and as the number of samples is increased, the mean estimates will converge to 4.1 and 4.4, and the confidence of these estimates will increase. Even though you do not have sub-integer resolution, by analysing the distribution of integer samples, you can deduce that your samples have in fact been taken from two independent underlying populations.

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