Planck, BICEP2, dust, and science news

The Planck Collaboration has released a paper describing the dust polarization in the CMB for the patch of sky used recently by BICEP2 to announce evidence for primordial gravitational waves. Things look bleak for BICEP2’s claims. See Peter Woit, Sean Carroll, Quanta, Nature, and the New York Times.

In the comments, Peter Woit criticizes the asymmetric way the whole story is likely to be reported:

I think it’s completely accurate at this point to say that BICEP2 has provided zero evidence for primordial gravitational waves, instead is seeing pretty much exactly the expected dust signal.

This may change in the future, based on Planck data, new BICEP2 data, and a joint analysis of the two data sets (although seeing a significant signal this way doesn’t appear very likely), but that’s a separate issue. I don’t think it’s fair to use this possibility to try and evade the implications of the bad science that BICEP2 has done, promoted by press conference, and gotten on the front pages of prominent newspapers and magazines.

This is a perfectly good example of normal science: a group makes claims, they are checked and found to be incorrect. What’s not normal is a massive publicity campaign for an incorrect result, and the open question is what those responsible will now do to inform the public of what has happened. “Science communicators” often are very interested in communicating over-hyped news of a supposed great advance in science, much less interested in explaining that this was a mistake. Some questions about what happens next:

1. Will the New York Times match their front page story “Space Ripples Reveal Big Bang’s Smoking Gun” with a new front page story “Sorry, these guys had it completely wrong?” Or will they bury it in the specialized “Science” section tomorrow with some sort of mealy-mouthed headline like the BBC’s today that BICEP just “underestimated” a problem?

2. Will Scientific American in the next few months put out a magazine cover saying “Our October magazine cover was nonsense”?

3. Will the BICEP2 team withdraw their PRL paper?

4. Will Linde/Guth/Starobinsky return their May Kavli Prize, which was awarded with the explanation
“More evidence was provided earlier this year by an experiment at the South Pole called BICEP2 which, however, awaits confirmation by independent data. BICEP2 detected swirls in the polarisation of the CMB that are believed to be caused by the gravity waves spawned during inflation, as predicted by Alexei Starobinsky.” see
http://www.kavlifoundation.org/2014-astrophysics-prize-explanatory-notes

5. etc….

Maybe things are different in the experimental world, but based on a long career of watching hype about strings, susy, extra dimensions never matched by public explanations of what went wrong, I’m not so optimistic.

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2 Comments

  1. Why one Earth would they withdraw their PRL? The data is genuine, its interpretation might be false or lacking but at the very least, other teams will know better what to be careful of for the next studies to come.

    • I think Peter’s concern is mostly with media coverage, fancy publications, honors, awards, etc. Assuming that the BICEP2 data would be considered sufficiently notable to be published in PRL regardless of interpretation, then I agree there’s not much basis for a retraction. But if their publication in a high-visibility journal was due to an interpretation that wasn’t justified by a sober analysis of the data at the the time, then there does seem to be something to criticize.

      Of course, it may be that the policy of these sorts of journals is to publish based on interpretation but retract based only on material falsehood. But if so, then this is just the sort of asymmetric policy (which incentivizes intellectually hype) that I think Peter is criticizing.

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