Follow Up On Solar Neutrinos and Radioactive Decay 183
An anonymous reader writes "A few days ago, Slashdot carried a story that was making the rounds: a team of physicists claimed to have detected a strange variation in radioactive decay rates, which they attributed to the mysterious influence of solar neutrinos. The findings attracted immediate attention because they seemed to upend two tenets of physics: that radioactive decay is constant, and that neutrinos very, very rarely interact with matter (trillions of the particles are zinging through your body right now). So Discover Magazine's news blog 80beats followed up on the initial burst of news and interviewed several physicists who work on neutrinos. They are decidedly skeptical."
Re:Wait till the religion fanatics hear this. (Score:4, Informative)
Since TFA says that the decay has slowed down, that would be the case
Radioactive decay is not constant (Score:2, Informative)
Radioactive decay is not constant, it's random. What's constant is the probability that any given radionuclide will decay in a given unit of time. We only see constants like the half life come up because statistical effects smooth out the quantum randomness.
Re:I don't see the problem. (Score:5, Informative)
The release of a neutrino is the same as the absorption of an anti-neutrino and vice versa. Ergo, it should be expected that variations in total numbers of neutrinos of the specific energy linked to that specific type of decay event would result in a change in the number of decay events recorded
The chances of a neutron encountering an electron and a neutrino of exactly the proper energy at exactly the same time are vanishingly small.
We also already know that what appears random is often the result of never being able to have enough data and never being able to make the step sizes infinitely small in the calculations; that randomness, per-se, is actually pretty rare in nature.
Bell's theorem [wikipedia.org] tells us that quantum randomness cannot be explained by a lack of information (hidden variables).
Indeed, randomness would seem to violate the requirement that information cannot be created or destroyed.
Where do you get that idea? There is no law of conservation of information. We know that the entropy of the universe always increases. Therefore the information in the universe also increases.
If you don't see the problem and highly trained theoretical physicists do, you'd be better off asking them where the problem is rather than declaring them wrong.
Re:According to TFA (Score:3, Informative)
According to TFA, neutrinos shouldn't be altered much by solar flares
And according to that *very same article*, the researchers responded, pointing out that some flares are caused by core events, and so may correlate with neutrino flux changes.
So, what, did you just stop reading half-way through?
Re:Wait till the religion fanatics hear this. (Score:1, Informative)
So your sole support is a 29 year old quote from an article, written by somebody who may or may not have any expertise in the subject, in a now-defunct and obscure journal.
Re:I don't see the problem. (Score:3, Informative)
I think you're misapprehending the controversy here. One side says "This data shows that neutrinos affect radioactive decay, which is a problem for physics", the other says "That data doesn't show what you think it does, so there's no problem for physics". Nobody except you is saying "neutrinos affect radioactive decay, but it's not a problem for physics".
well known crackpot area (Score:5, Informative)
This idea that decay rates depend on environmental factors is well known as a fertile field for crackpots. Here's a FAQ I wrote about it.
FAQ: Do rates of nuclear decay depend on environmental factors?
There is one environmental effect that has been scientifically well established for a long time. In the process of electron capture, a proton in the nucleus combines with an inner-shell electron to produce a neutron and a neutrino. This effect does depend on the electronic environment, and in particular, the process cannot happen if the atom is completely ionized.
Other claims of environmental effects on decay rates are crank science, often quoted by creationists in their attempts to discredit evolutionary and geological time scales.
He et al. (He 2007) claim to have detected a change in rates of beta decay of as much as 11% when samples are rotated in a centrifuge, and say that the effect varies asymmetrically with clockwise and counterclockwise rotation. He believes that there is a mysterious energy field that has both biological and nuclear effects, and that it relates to circadian rhythms. The nuclear effects were not observed when the experimental conditions were reproduced by Ding et al.
Jenkins and Fischbach claim to have observed effects on alpha decay rates correlated with an influence from the sun. They proposed that their results could be tested more dramatically by looking for changes in the rate of alpha decay in radioisotope thermoelectric generators aboard space probes. Such an effect turned out not to exist (Cooper 2009). Undeterred by their theory's failure to pass their own proposed test, they have gone on to publish even kookier ideas, such as a neutrino-mediated effect from solar flares, even though solar flares are a surface phenomenon, whereas neutrinos come from the sun's core. Their latest claims, in 2010, are based on experiments done decades ago by other people, so that Jenkins and Fischbach have no first-hand way of investigating possible sources of systematic error.
Cardone et al. claim to have observed variations in the rate of alpha decay of thorium induced by 20 kHz ultrasound, and claim that this alpha decay occurs without the emission of gamma rays. Ericsson et al. have pointed out multiple severe problems with Cardone's experiments.
He YuJian et al., Science China 50 (2007) 170.
YouQian Ding et al., Science China 52 (2009) 690.
Jenkins and Fischbach (2008), http://arxiv.org/abs/0808.3283v1 [arxiv.org]
Jenkins and Fischbach (2009), http://arxiv.org/abs/0808.3156 [arxiv.org]
Jenkins and Fischbach (2010), http://arxiv.org/abs/1007.3318 [arxiv.org]
Cooper (2009), http://arxiv.org/abs/0809.4248 [arxiv.org]
F. Cardone, R. Mignani, A. Petrucci, Phys. Lett. A 373 (2009) 1956
Ericsson et al., Comment on "Piezonuclear decay of thorium," Phys. Lett. A 373 (2009) 1956, http://arxiv4.library.cornell.edu/abs/0907.0623 [cornell.edu]
Ericsson et al., http://arxiv.org/abs/0909.2141 [arxiv.org]