Follow @PoliticsIE
 
 
 
Results 1 to 5 of 5

Thread: Solar activity may affect nuclear decay rates on earth

  1. #1
    Politics.ie Member seabhcan's Avatar
    Join Date
    Sep 2007
    Posts
    14,309
    Mentioned
    0 Post(s)

    Default Solar activity may affect nuclear decay rates on earth

    Very interesting science this.

    New system could predict solar flares, give advance warning

    Nuclear decay of any particular radioactive nuclei is supposed to be random and independent of everything else in the universe. The rate of nuclear decay is based on probability, and supposedly constant and universal for a particular material. There is a lot of science built on these assumptions.

    Some scientists in the US have found a correlation between the rate of nuclear decay and the time of year, and solar activity. Their theory is that the flow of neutrinos from the sun arriving to earth (which varies depending no how close we are to the sun - we are closest during the northern hemisphere's winter) influences when radioactive atoms decay. Basically, neutrinos sometimes hit an unstable nucleus and make it pop - more neutrinos means more decay.

    There are quite a few implication of this. If you had a spacecraft powered by nuclear decay, the power output would decline the farther it went from the sun. I believe Voyager has seen a decline in power output - some of which is expected for other reasons.

    More solar activity would cause an increase in volcanic activity on earth - as the heat in the mantle is due to nuclear decay. Active solar periods might explain some of the more volcanic periods in earth history.

    Carbon dating also becomes suspect. In normal times, this effect would cause 1% per year uncertainty in carbon dating. But we don't know if the sun was more or less active in the past. So its hard to put a number on that one.

  2. #2
    Politics.ie Member
    Join Date
    Apr 2009
    Posts
    55,716
    Mentioned
    2 Post(s)

    Default

    Interesting - I had been reading about this only a few days ago. Apparently the biggest challenge for the solar explanation of the changed rate of decay is that there is no understood mechanism whereby neutrinos could have this effect on atomic nuclei. The alternative suggestion is a previously unknown partice.
    Could prove to be of considerable significance, either way.

  3. #3
    Politics.ie Member seabhcan's Avatar
    Join Date
    Sep 2007
    Posts
    14,309
    Mentioned
    0 Post(s)

    Default

    Quote Originally Posted by Sailor View Post
    Interesting - I had been reading about this only a few days ago. Apparently the biggest challenge for the solar explanation of the changed rate of decay is that there is no understood mechanism whereby neutrinos could have this effect on atomic nuclei. The alternative suggestion is a previously unknown partice.
    Could prove to be of considerable significance, either way.
    True about the neutinos - but they are fairly mysterious things so there is plenty of room in the physics to make this possible. They have mass, probably, and they do hit things (which is how we know they exist) so it does seem likely that if they hit an already unstable nuclei that the additional energy would make decay more likely.

    This is (almost) on of those 'of course they do' discoveries. It rings true.

  4. #4
    Politics.ie Member SAT's Avatar
    Join Date
    Mar 2009
    Posts
    9,625
    Mentioned
    0 Post(s)

    Default

    Quote Originally Posted by seabhcan View Post
    True about the neutinos - but they are fairly mysterious things so there is plenty of room in the physics to make this possible. They have mass, probably, and they do hit things (which is how we know they exist) so it does seem likely that if they hit an already unstable nuclei that the additional energy would make decay more likely.

    This is (almost) on of those 'of course they do' discoveries. It rings true.
    The curious part is, although it doesn't say so explicitly, this article suggests, The strange case of solar flares and radioactive elements the decay rate dropped as more neutrinos were ejected, whereas the point was meant to be more neutrinos increase the decay rate.

    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.
    ps It seems to be more complicated than a straight forward correlation.

    Dr Fischbach admits that while whatever process generated the flare in 2006 also caused a dip in neutrino flux, and a corresponding drop in radioactive decay rates, other processes seem to have the opposite effect. For example, a storm in 2008 was preceded by a spike in manganese-54 decay rates.
    http://www.economist.com/blogs/babba...d-solar-storms
    Last edited by SAT; 27th May 2013 at 10:57 AM.

  5. #5
    Politics.ie Member seabhcan's Avatar
    Join Date
    Sep 2007
    Posts
    14,309
    Mentioned
    0 Post(s)

    Default

    Quote Originally Posted by SAT View Post
    The curious part is, although it doesn't say so explicitly, this article suggests, The strange case of solar flares and radioactive elements the decay rate dropped as more neutrinos were ejected.
    Weird.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •