Can Rotational Motion Effect Radioactive Decay?

This post is an analysis of "Changes of decay rates of radioactive 111In and 32P induced by mechanic motion" by YuJian He, Fei Qi and ShengChu Qi, located at http://www.springerlink.com/content/x1q13217t2427059/

Summary: Two different radioactive isotopes were put in a centrifuge and spun. The half-life appeared to increase if spun one way and decrease if spun the other way.
Claim: There is a difference and it can be explained by the chiral dependence of the weak force.

Question 1: Are the results "Significant"?
Statistically, is the proof strong enough to not just be a coincidence? Well... somewhat. For 111In they measure a "natural" half life of 2.83 +/- 0.03 days, clockwise is 2.75 +/- 0.03 days, and anticlockwise it is 2.88 +/- 0.03 days. None of this is the "3 sigma" difference which is necessary in particle physics (though not other fields) to claim an observation.

For 32P the natural is 14.29+/-0.03 days, clockwise is 13.75+/-0.03 days, and anticlockwise is 14.54 +/- 0.03 days. This is a "significant" observation if those errors are true.

It is somewhat unclear where these errors are coming from. They claim to fit their data in Excel, so perhaps that spit out a fit uncertainty. However, they quote the SAME errors for the other isotope even though the half life is an order of magnitude different. They don't provide any measure of "how good" their fit is - like a chi2 test.

Answer: Some of their results do not appear to be statistically significant. Their error bars are not explained so significance cannot really be judged. I can't say their results are "wrong", but they are not good science

Question 2: Is the mechanism they explain the effect with reasonable?

This is dangerous territory since they appear to be chemists and anything effecting radioactive decay half life would be a physics process. Unfortunately this section is poorly written, presumably because English is their second language. This makes it somewhat difficult to tell if what they are saying is nonsense or if it just sounds this way. The general idea is that elementary particles have a property called chirality that relates to spinning clockwise or counterclockwise. It appears as if the authors of this paper try to relate chirality to all sorts of things.

The first problem is that the "physics paper" they cite to discuss the chiral nature of the Weak Force is a Scientific American paper from 1990. This is scary! Scientific American has articles on whether robots will rule the world any time soon. It is not a good source for citing the fundamental rules of the universe. Yes, there is a preference for particles to "spin" clockwise vs counterclockwise. I don't think the authors understand what this means.

Spin is a technical term in physics and is inherently quantum mechanical. It is possible to align the spins of particles, but it must be done on a quantum mechanical level. The authors haven't modified the orientation of the spins of the atoms in their sample (for instance, by putting them in a very strong magnetic field like in MRI or cooling them down to almost 0 kelvin) so they will be randomly distributed. Basically, the motion of the centrifuge in this paper is too "big" for the individual atoms/particles to know that there is a difference between clockwise and anticlockwise.

Answer: No, they seem to misunderstand the physics concept they are citing

Final Conclusion: The most generous judgment is that they misunderstood the physics process and didn't properly consider their sources of measurement error. I would judge it "Sloppy Science" and am surprised it was published in a peer reviewed journal. Perhaps the reviewers didn't understand the physics either.

Science: Made in China?

Unfortunately the "rules" about diagnosing "Bad Science" break down when the research is done in another country, such as China. There are brilliant Chinese Scientists. There are wonderful research facilities and institutions in China. But there can also be a lack of communication between Science in China and Science in the USA.

So here is the scenario:

• A paper is published in a Chinese Chemistry Journal (in English) in 2007
  
• The journal is peer-reviewed
  
• One of 3 authors has no affiliation; the other 2 sound like good Chinese Institutions
  
• The results are surprising and have consequences in Physics, Chemistry, and Biology
  
• The authors explain the strange result via Physics, but are in Chemistry Departments
  
• It has only been cited 2 times, once by a different group not able to confirm the results and once by the original group rejecting the results of the 2nd group.
  
• There are some communication issues in the paper; it isn't written in the "scientific tone" that I am used to
  
• Of the 12 references, 6 are to papers written by the same authors
  

Diagnosing "Bad Science"

Science is often referred to as one entity (especially in political discussions), but there is no specific line between what is "Science" and what isn't. There is a bunch of "stuff" that gets done by people (many of whom call themselves scientists) and some of this "stuff" is done more scientifically than others. The scientific method we teach in primary school (make a hypothesis, test the hypothesis, etc) doesn't always map well to the research industry. Much of the time - especially in interdisciplinary research - it is difficult to know all of the possible effects and think of all of the variables.

Hence, there is a system for people (who identify as scientists) to discuss research. One arm of this system are conferences - face to face meeting filled with talks and posters. Another is journals, especially the "peer reviewed" ones.