Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Nuclear decay rates possibly correlate with distance from Sun

  1. Aug 29, 2008 #1

    Mk

    User Avatar

    http://arxiv.org/abs/0808.3283
    This is weird as hell. As far as I knew, nuclear decay rates were not affected by anything, except beta decay under electromagnetic fields. This could possibly have huge consequences in other sciences. Personally, I immediately went to post this in Earth. Paleoclimatologists collect data over hundreds to millions of years based on isotope ratios and nuclear decay rates. Anthropologists, archeologists, geologists— they all do as well, but who knows!

    By that they mean the fine structure constant. They cite this paper: http://arxiv.org/abs/0806.4317

    They also cite this paper in saying:
    http://arxiv.org/abs/0808.3156
    Interesting, all these papers came out at about the same time in 2008. Nice stuff. I'm not a frequent poster in this forum, but I thought it would be placed well here and get some good discussion on these three papers. If it should be moved by a moderator, then go ahead and move it.
     
  2. jcsd
  3. Aug 29, 2008 #2

    arivero

    User Avatar
    Gold Member

    I guess that this is the conjecture under test: that beta decay rates could be sensible enough to the variation of solar neutrinos. Weird indeed.
     
  4. Aug 29, 2008 #3
    Has the paper been (expert) peer reviewed? (A little thing like that doesn't stop slashdot running with it of course..) Any attempts at running an identical apparatus in the opposite hemisphere?
     
  5. Sep 2, 2008 #4

    CarlB

    User Avatar
    Science Advisor
    Homework Helper

    Another, somewhat less convincing, recent article with some of the same authors is:

    Perturbation of Nuclear Decay Rates During the Solar Flare of 13 December 2006
    Jere H. Jenkins, Ephraim Fischbach
    http://arxiv.org/abs/0808.3156

    As far as the validity of the paper, they've got 6 authors, which is a bit too many to overlook something obvious, but only Jenkins has a lot of papers to his credit.

    I can see how a neutrino flux might modify beta decay; it would be a sort of lasing effect if the frequencies were right. But I don't see how neutrinos could possibly effect a decay that emitted an alpha particle, unless it was a cascade or something like that, but that's not the case, Ra-226 is a straight alpha emitter:
    http://en.wikipedia.org/wiki/Radium

    Rather than neutrino flux, I would think that a dependence on gravitational potential would be more likely, especially given that the rate has a small phase difference from the distance to the sun (a lag).
     
  6. Sep 2, 2008 #5

    Vanadium 50

    User Avatar
    Staff Emeritus
    Science Advisor
    Education Advisor
    2015 Award

    I think it's far more likely that the authors are observing a seasonal variation in detector performance.

    There are two things in the back of my mind when I read this. One is that the authors were re-analyzing someone else's data: they weren't there when it was taken. That immediately puts them at a disadvantage. (In fact, it's even possible that this effect was noticed by the original experimenters, and the reason identified).

    The other is that Fischbach has a track record of finding dramatic new physics effects in other people's data - effects that subsequently are shown not to exist.
     
  7. Sep 2, 2008 #6

    vanesch

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    This is also what came to my mind. I once had an unexpected variation in a detector efficiency with a time constant of a few hours, and it turned out to be perfectly correlated with the airconditioning which switched on and off to keep the temperature about constant (but nevertheless, the 0.5 degree variation or so was noticable).

    That said, in the paper, they compare to a reference each time, which seems to have remained flat, so in principle this has been taken into account...
     
  8. Sep 2, 2008 #7

    CarlB

    User Avatar
    Science Advisor
    Homework Helper

    In addition, Fishbach has a paper claiming that the neutrinos weigh at least 0.4 eV (snicker). But there are a bunch of other authors.
     
  9. Sep 2, 2008 #8

    arivero

    User Avatar
    Gold Member

    He argues that it is different latitude; but one could be safer if it were different hemisphere. If they are in the same day/night pattern, I vote for radiation and consum patterns from the light bulbs/discharge tubes. The air conditioning system is also a suspect, yes.

    There is a scent of almost-recursivity in this research: Do you mean that there is a pattern in Fischbach data :biggrin:?
     
  10. Sep 2, 2008 #9

    arivero

    User Avatar
    Gold Member

    Perhaps an increase in the phase space available for disintegration? No sure, but for fision there is a peculiar colective phenomena around: the lower peak, corresponding to the more abundant subproduct, lives at 81 GeV (told at https://www.physicsforums.com/showthread.php?t=227263 ). In any case, in the NZ plot you can see that the other huge peak in the total collection of measured beta decays corresponds to the corner of the theoretical alpha line, next to the magic N=82.

    Even -Lubos labeled me recently as an archetypal model of gullibility- I myself am unable to see how a grav variation could work. Next step is to look for tidal patterns.
     
    Last edited: Sep 2, 2008
  11. Sep 2, 2008 #10

    Vanadium 50

    User Avatar
    Staff Emeritus
    Science Advisor
    Education Advisor
    2015 Award

    The BNL work compares Si-32 to Cl-36. Si-32 is a beta emitter, and Cl-36 decays by K-capture most of the time, with a tiny fraction of positron emission. So you will have different energy spectra, a different particle mix, and a different number of Auger electrons. A subtle difference in response is not hard to imagine.

    Note that the original experimenters didn't have to worry about this, since over a multiyear run these effects would average out.
     
  12. Oct 5, 2008 #11
    Decay Rate Variance Claimed

    A pair of researchers are claiming to have found variance in alpha decay rate, which they have correlated with solar neutrinos:

    http://physicsworld.com/cws/article/news/36108

    Are they onto something, or just barking up the wrong tree?
     
  13. Oct 5, 2008 #12
    Re: Decay Rate Variance Claimed

    You've not checked, have you ?
    [thread=252518]Nuclear decay rates possibly correlate with distance from Sun[/thread]
     
  14. Oct 6, 2008 #13
    Re: Decay Rate Variance Claimed

    The most likely explanation is an imperfection in their experimental setup (either the clock or the detector) that makes readings depend on an external factor.

    As far as correlations with solar flares, their chart is not very convincing. They should set up two systems in two different rooms (different buildings, if possible) and see if they get strong correlation between decay rates. If there is, then you can search for an external factor that affects decay rates - solar flares, neutrinos, axion flux, etc.
     
  15. Oct 6, 2008 #14

    Vanadium 50

    User Avatar
    Staff Emeritus
    Science Advisor
    Education Advisor
    2015 Award

    Re: Decay Rate Variance Claimed

    As mentioned in the other thread, this is impossible. The authors did not do the experiment; they are analyzing someone else's experiment.
     
  16. Oct 12, 2008 #15

    jtbell

    User Avatar

    Staff: Mentor

    Re: Decay Rate Variance Claimed

    Um, that's this very thread. :confused:

    Or did someone merge two threads?
     
  17. Oct 13, 2008 #16

    Vanadium 50

    User Avatar
    Staff Emeritus
    Science Advisor
    Education Advisor
    2015 Award

    The threads were merged.

    I looked at the solar flare data and find it completely unconvincing. I see the decay rate bouncing all over the place, and sometimes this bouncing happens to be near a solar flare. The authors assume they have no systematic uncertainties, which is clearly not the case if you ask how well the off-flare data fits the curve.
     
  18. Apr 22, 2010 #17
    It is interesting to note that there is a phase lag. That is to say there is a delay in the affect to reach peak and there is a delay in the affect to reach minimum. That observation supports the assertion that there is a build up and a build down associated with what every is causing what is observed. One hypothesis presented in the paper is that solar neutrinos somehow change nuclear decay rates. A problem with that hypothesis is that as neutrinos travel at the speed of light and do not build up or build down, there would be no delay if neutrinos were the cause. The neutrino hypothesis does not explain the phase lag.
     
  19. Sep 5, 2010 #18
    We were discussing possible observational evidence of variance of fine structure with redshift. I see there is a reference to fine structure changes and scalar fields in this paper.

    As noted above there is evidence of a time lag in the observational change in the nuclear decay rate where the strongest effect occurs after the earth reaches aphelion or perihelion. A lag in the affect points to some other cause than neutrinos as neutrinos are thought to travel at the speed of light.

    A second observation point that points away from the neutrino mechanism is the nuclear decay change is affecting both beta and alpha decay, beta decay is not affected by neutrinos.

    I see the authors are proposing a solar created scalar field as a possible mechanism to explain the effect. That would explain the time delay in the mechanism and why it affects both alpha and beta decay.

    I see a subsequent paper that notes there is a change in the decay rate prior to a solar flare.

    Following the solar scalar field hypothesis, to explain a change in nuclear decay rates prior to a solar flare, the hypothesis would be the scalar field varies prior to the solar flare and the variance in the scalar field is perhaps related to what is causing the solar flare.

    Thinking along the line of a scalar field as a possible mechanism it would be interesting to ask does the scalar field show long term variance?

    If you think along that the hypothesis of the scalar field hypothesis rather than the neutrino line, then observations of the nuclear rate dependency and the sun earth distance are also dependent on the long term evolution of the large solar scalar field. (i.e. The point is that the observed affect over decades, centuries, and millennium will not necessarily be constant and hence may be discounted as insignificant because of the observational period in question.)

    I have looking for other astronomical observational evidence which might provide support for a hypothesis along that line and insight into how the mechanism might work. I have found some material concerning Lithium deficient stars and planetary formation which is interesting. The hypothesis is that there are different types of stars and the Lithium deficiency which occurs in roughly 7% of stars and a mechanism to create a hypothesized scalar field would be related to planetary formation.

    I started researching solar magnetic affects CME and solar flares looking for a mechanism that could cause possibly cause observed large geomagnetic inclination changes (the orientation of the geomagnetic field abruptly changes and there is some change in the intensity of the geomagnetic field at the time of the event) changes in the earth geomagnetic field referred to as archeomagnetic jerks. (Archeomagnetic jerks are different than geomagnetic jerks which are rapid changes to the geomagnetic field. Archeomagnetic jerks are large inclination changes in the geomagnetic field and are called archeomagnetic jerks as one of analysis tools is the study of ancient pottery to determine the orientation and the intensity of the geomagnetic field at the time at the time the pottery has formed.) There have been 10 archeomagnetic jerks observed in the last 2000 years.

    Following the line of thought of a scalar field one would expect changes in the size of the earth's ionosphere which correlate with changes in the solar magnetic cycle which I see are also observed.

    http://arxiv.org/PS_cache/arxiv/pdf/0808/0808.3283v1.pdf

     
  20. Sep 5, 2010 #19

    CarlB

    User Avatar
    Science Advisor
    Homework Helper

    The surprise is that alpha decay rates would be modified; beta and anti-beta decay seem more likely to have something to do with anti-neutrinos and neutrinos (via some sort of stimulated emission of radiation). One of the references I saw proposed that the alpha decay rates were not modified; instead, what was being seen was an influence on the decay of the daughter products. The influenced alpha decay mentioned was Ra 226. The (>99%) decay chain is:

    88 Ra 226 alpha decays to 86 Rn 222; 1,601 years

    86 Rn 222 alpha decays to 84 Po 218; 3.8 days

    84 Po 218 alpha decays to 82 Pb 214; 3.1 minutes

    82 Pb 214 beta minus decays to 83 Bi 214; 26.8 minutes

    83 Bi 214 beta minus decays to 84 Po 214; 19.9 minutes

    84 Po 214 alpha decays to 82 Pb 210; 164 microseconds

    82 Pb 210 beta minus decays to 83 Bi 210; 22.3 years

    83 Bi 210 alpha decays to 81 Tl 206; 3 million years

    81 Tl 206 beta minus decays to 82 Pb 206; 4.2 minutes

    82 Pb 206 is stable

    In the above chain, 82 Pb 210 with a half-life of 22.3 years would tend to build up as all the isotopes higher up the decay chain have much much shorter half lives. So as a pure sample of Ra 226 ages (google "secular equilibrium"), it will build up 82 Pb 210 which decays by beta minus with a half life long enough to see a yearly influence. And then 83 Bi 210, on the scale we're looking at, is essentially stable.

    I got the above data from:
    http://education.jlab.org/itselemental/index.html
     
  21. Sep 5, 2010 #20
    This is a new paper by a separate set of authors concerning the alleged annual variation of nuclear decay rates. The conclusion of the study is that the effect is real however additional investigation is required to determine its cause.


    http://arxiv.org/PS_cache/arxiv/pdf/1007/1007.0924v1.pdf

     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?



Similar Discussions: Nuclear decay rates possibly correlate with distance from Sun
  1. Nuclear decays (Replies: 6)

  2. Nuclear decay (Replies: 3)

  3. Nuclear Decay (Replies: 1)

Loading...