Horace Heffner wrote: > Here is the original article > > http://arxiv.org/pdf/0808.3283v1 > > Here is a follow-on article looking for any variations in decay rates > of Pu 238. > > http://arxiv.org/pdf/0809.4248v1 > > "Data from the power output of the radioisotope thermoelectric > generators aboard the Cassini spacecraft are used to test the > conjecture that small deviations observed in terrestrial measurements > of the exponential radioactive decay law are correlated with the > Earth-Sun distance. No significant deviations from exponential decay > are observed over a range of 0.7 - 1.6 A.U. A 90% Cl upper limit of > 0.84 x 10^-4 is set on a term in the decay rate of Pu-238 > proportional to 1/R^2 and 0.99 x 10^-4 for a term proportional to 1/R." >
Spacecraft is outside the ambit of the Earth. That could imply a different result. And the kind of decay, experimental conditions, and methods, are all things that must be also taken into consideration. > It may not be distance that is the primary factor. It certainly is > Not distance directly, of course, but something that changes accordingly with, or depending on, distance. > known that various factors affect decay rates. For example, here are > some whopping statements from: > > http://www.newscientist.com/article/mg20327190.100-nuclear-decay- > puzzle.html > > "... a previous New Scientist article (21 October 2006, p 36) ..." > reported "they could modify the radioactive decay of certain > radioisotopes by encasing them in metal and chilling them close to > absolute zero." "... (11 November 2006, p 26)..." , Otto > Reifenschweiler "found that the radioactive decay of tritium absorbed > in titanium particles could be reduced by 40 per cent at temperatures > between 115 °C and 275 °C (Physics Letters A, vol 184, p 149)". "The > most dramatic change in radioactive decay has, however, recently been > observed by Fabio Cardone and others on the decay of thorium-228 by > using ultrasonic cavitation in water (Physics Letters A, vol 373, p > 1956). In this case, the radioactive decay rate was increased by a > whopping factor of 10,000." > Impressive. Although not surprising. At least, not to me :-) I've always felt that the curious value of the free neutron half life(885.7 secs) must be a consequence of the local environment. A feeling like that has almost zero scientific value, of course :-) > > Here is an antineutrino theory: > > http://www.mindandmuscle.net/forum/index.php?showtopic=38667 > > "Nuclei such as silicon-32 undergo beta decay, during which a neutron > in the atomic nucleus decays into the slightly less massive proton. > As it does so, it emits an electron and a near-massless particle, an > antineutrino. As antineutrinos are notoriously difficult to detect, > beta decay is signalled simply by a nucleus spontaneously emitting an > electron." > > "Fischbach and Jenkins suggest that another reaction would, in > theory, have the same signature. If a neutrino - a sister particle to > the antineutrino - knocked into a neutron in an atomic nucleus, it > would produce a proton and an electron. The nuclear fusion reactions > that power the sun's core are spewing neutrinos equally in all > directions. The further away from that source you go, the more spread > out those neutrinos are. The higher flux of neutrinos through the > Earth when it is close to the sun would therefore bump up nuclear > decay rates" > The problem with this is that neutrinos are said to interact very feebly with matter. Whatever the reason or reasons are for these fluctuations, its mechanisms are outside the actual physics paradigm. And that's the most interesting ingredient in all this. Thanks for the links. If I come up with a better match for the bnl data I'll announce it here. Mauro > > Other related URLs: > > http://physicsworld.com/cws/article/news/361i > > http://www.blog.thecastsite.com/?p=95 > > http://findarticles.com/p/articles/mi_m1200/is_11_174/ai_n31179075/ > > http://www.sciencenews.org/view/feature/id/38341/title/Half-life_ > (more_or_less) > > http://maurol.com.ar/decay_rates/velocity_distance.png > > > Best regards, > > Horace Heffner > http://www.mtaonline.net/~hheffner/ > > > > > >
