Last month, researchers at CERN, the European high-energy-physics lab that houses the world’s most powerful atom smasher, announced that they had detected a subatomic particle in the act of breaking the speed limit posted by Officer Einstein. In other words, their data indicated that the particles—very light, hard-to-detect items called neutrinos—covered a distance of some 400-plus miles and took about sixty-billionths of a second less time than they should have. It’s like the man who said good-by to his wife and drove his sports car to a town 80 miles away. When he got there she called him and asked: “Are you there yet?” When he said yes, she said, “Well, you’ve been speeding again. You left 45 minutes ago.” The neutrinos got from CERN’s accelerator (it’s so big it covers portions of France and Switzerland, I believe) to an underground detector in Gran Sasso, Italy a little too faster than they should have.
If the results are independently confirmed, they will rank as one of the most important experimental discoveries of the century. And if they are not, they will show how the way science is conducted has changed over the last few decades, and not for the better.
I am not a professional physicist, though I know enough about the subject to start squinting when someone comes up with a claim that anything, from a microwave to a piece of peanut brittle, has been measured as traveling faster than the speed of light. One of the two pillars of modern science is relativity, whose fundamental postulate is that no signal (an event capable of carrying information) can travel faster than the speed of light in a vacuum. (The other pillar is quantum mechanics.) So within hours of the announcement, theorists had lined up on both sides of the aisle, one group claiming that the discovery confirmed their pet theories, and the other citing seventeen different reasons why the experimentalists had to be wrong. It was quite a show.
And the show-business aspect is why the whole scene bothers both me and Laurence Krauss, a highly qualified physicist who wrote an op-ed piece in the L. A. Times criticizing the way the discovery was presented.
The normal procedure is for scientists to submit new work to a refereed journal. In many fields, this step is preceded by informal publication on a site such as arxiv.org, where non-refereed papers can be published online under certain conditions. But everybody understands this is tantamount to thinking out loud, and an essential part of the scientific process of investigating the validity of new results is for qualified colleagues to critique the paper during the process of peer review by referees. Sometimes this results in the paper being rejected, but more often, criticism in the right spirit points out weaknesses or omissions that the authors can correct to make the final publication even better. Only when the paper is published (and in the case of unusual results such as CERN’s, duplicated by different laboratories), should the public in general be informed that, hey, we may really have something here.
As is so often done these days, however, the CERN authors called a news conference to discuss the implications of their paper before it had been peer-reviewed. This short-circuits the referee process and puts highly digested and simplified versions of the science out into the general blogosphere, where hun-yocks like me can have a go at it whether we are qualified or not.
As Krauss points out in his opinion piece, the result is a brief flurry of ambiguous reports of the original news, together with pro- and con-comments from other experts which largely cancel each other out. Then the whole thing is forgotten, at least by the non-experts who hear about it between an ad for an energy drink and the latest on how the Texas Rangers are doing. It’s this kind of thing that gives science a bad name. It will take a lot of work to degrade the prestige of science down to the point where the average citizen will take the word of a Congressman over the word of a physicist, but news conferences about results that haven’t been peer-reviewed take us a little bit in that direction.
I have probably mentioned that years ago, I attended a conference in China at which an otherwise well-reputed professor of microwave engineering reported that he had measured microwaves traveling at a speed greater than light. I wrote an article on his work, and included some other examples of instances where experimentalists deluded themselves, not out of a desire to deceive, but out of a combination of inadequate care to keep their own psychology from skewing the process, and a strong wish to discover something remarkable.
There’s nothing wrong with wanting to discover something remarkable. I have had that desire off and on myself. But doing new science is very hard work, and when you get a result that would upset most of the applecart of existing physical law, the first thing to do is not rush out and invite in a bunch of science reporters. The thing to do is to ask your colleagues, including your worst enemies, to come over and throw as many rocks as they can at your methods, your calculations, your assumptions, and your instrumentation (metaphorically speaking, of course). The more remarkable the result, the more rocks.
The worst that can happen this way is that you will be humbled to discover where you have made your mistake, and both you and your critic will have learned something. You will learn what you did wrong, and your critic will learn that you are the type of physicist who can benefit with good grace from constructive criticism. And you will avoid looking foolish in public, because the situation will have been kept among professionals rather than plastered all over the Internet.
Instead, the CERN people have stuck their necks out and made headlines (and engendered a lot of jokes, too, but that’s somewhat beside the point). Whether they deserve the headlines remains to be seen. If the result holds up (which I personally think it won’t—their geographic accuracy alone had to be on the order of ten feet in 400 miles), they will deserve not only the favorable publicity they have gotten already, but probably a Nobel Prize. If the result is shown to be in error, you probably won’t see a single headline about it. There will just be a lot of question marks in the public’s mind like, “Didn’t they say something goes faster than light? Wonder what happened to that? Those scientists can’t make up their minds about anything anymore.” And that won’t be good for science.
Sources: The CERN news was reported by many sources, and appeared with commentary on the Scientific American website http://blogs.scientificamerican.com/degrees-of-freedom/2011/10/02/superluminal-neutrinos-would-wimp-out-en-route/
Laurence M. Krauss’ op-ed piece appeared at http://www.latimes.com/news/opinion/commentary/la-oe-krauss-neutrino-20111004,0,7882894.story
And my article on the supposedly superluminal microwaves was entitled "N-rays, super-dielectrics, and microwaves faster than light: improbable discoveries in electromagnetics," and appeared in IEEE Antennas and Propagation Magazine, vol. 35, no. 3, pp. 13-18, June 1993; a letter by me pertaining to the same subject was published in IEEE Antennas and Propagation Magazine, vol. 36, no. 5, p. 72, Oct. 1994. And I’ve used “hun-yock” before—look it up at http://www.urbandictionary.com/define.php?term=Hunyock.
No comments:
Post a Comment