Does the truth wear off in Physics?

In The Truth Wears Off, Is there something Wrong with the Scientific Method? Jonah Lehrer claims  “the weak coupling ratio exhibited by decaying neutrons, which appears to have fallen by more than ten standard deviations (emphasis added) between 1969 and 2001.”


The Particle Data group publishes the data.

I presume Lehrer refers to the axial vector coupling ratio of neutron decay, g_A/g_V. The initial measurement was -1.22 +/- 0.22.  The most current measurements are -1.27+/- .05.

So the difference is about 18% (hardly a large shiftO.   It is more negative, but a larger magnitude rather than a declining effect, and only 3 of the original standard deviations from the original measurement. Using the current, more precise measurement standard deviations is both incorrect and misleading. I’m pretty underwhelmed. Abuse of the statistics leads me to question more of the article.


Johah Lehrer, The Truth Wears Off, Is there something Wrong with the Scientific Method? December 13 2010, The New Yorker.


About Bill Nichols

PhD in Physics from Carnegie Mellon University I'm a software team coach and instructor with the TSP Team at the Software Engineering Institute
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4 Responses to Does the truth wear off in Physics?

  1. Thanks, Bill. I enjoyed the Lehrer article, but when he made that unsourced statement about changing neutron decay without further elaboration, I was suspicious and spent a good deal of time searching for data online to investigate.

    • Bill Nichols says:


      You’re welcome. I got a little lucky finding that particular page. It is true that the neutron lifetime measurement has gotten shorter, but measuring the neutron lifetime is HARD. You cannot contain them because they are uncharged, the lifetime is measured in minutes, and even a thermal neutron moves a typical speed of 2200 m/s. It’s not surprising that the early measurements were off. The problems are very different from the clinical effects in drug tests or what I measure now in software engineering.

  2. DA says:

    You’ve got a misprint in that data. It was -1.20 +/- .02 and settled on -1.27 +/- .005. (That’s eying it form the graph.)

    Anyway, thanks for looking it up. I’m trying to make sense of that article. I am concerned that it could be a propaganda piece meant to cover for the basic corruption in medical research – as you notice it starts with discussion of atypical antipsychotics, which have made the pharma companies _lots_ of money. Results “disappear” in pharma reserch because they were manipulated in the first place. To quote Richard Smith, the 25 year head of the BMJ, “[I required] almost a quarter of a centry editing … to wake up to what was happening … The companies seem to get the results they want not by fiddling the results, which would be far too crude and possibly detectable by peer review, but rather by asking the `right’ questions — and there are many ways to do this … many ways to hugely increase the chance of producing favourable results, and there are many hired guns who will think up new ways and stay one jump ahead of peer reviewers.” And Drummond Rennie, deputy editor of JAMA adds, “This is all about bypassing science. Medicine is becoming a sort of Cloud Cuckoo Land, where doctors don’t know what papers they can trust in the journals, and the public doesn’t know what to believe.”
    Quoted p.144 & 159 of “Doubt is their Product: How Industry’s Assault on Science Threatens Your Health” by David Michaels (Ex & present head of OSHA)

  3. Peter Fessel says:

    Jonah Lehrer has been fired from the New Yorker, and his recent book is being recalled by the publisher for fraud.

    See link:

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