Science And Credibility: The Case Of The Not-So-Fast Neutrinos

Science And Credibility: The Case Of The Not-So-Fast Neutrinos
February 29, 2012
by Marcelo Gleiser - NPR

After much brouhaha, media frenzy and Einstein bashing, the verdict is out on the faster-than-light neutrinos. Or nearly so. Scientists at the CERN particle physics laboratory in Geneva, Switzerland have confirmed that a loose fiber-optic cable is the most probable culprit in the much-announced violation of the foundational stone of Einstein's theory of relativity, that nothing can travel faster than light.

In a statement from the OPERA collaboration, responsible for the measurements at the Gran Sasso laboratory in Italy, two effects were identified as possibly having caused changes in the neutrinos' travel time through 730 km of Earth's crust from Switzerland to Italy: in the first effect, a faulty connection between the fiber-optic cable bringing GPS signals to OPERA and the detector's master clock would have shortened the time of flight. However, to confuse things a bit, the other effect, when corrected, could in principle shorten the time of flight again: a device within a detector in OPERA that gives time readings synchronized to GPS signals.

Since the two effects work against each other, at this point scientists at CERN and at OPERA are studying their "potential extent," to decide which source of error outweighs the other. Lucia Votano, director of the Gran Sasso laboratory, says that the "main suspicion" lies with the optical-fiber connection. Things remain unclear, although they are definitely being cleared up. In May, the two labs will redo measurements with short-pulsed beams designed to give readings with much higher precision than what has been done to date. The case will be closed then.

In September 28 2011, I wrote in these pages:

"Although the team of scientists was extremely careful to take into account all possible systematic errors, it's highly probable that something is still eluding them. It could be related to the process that generates the neutrinos, it could be related to timing issues in the detectors, it could be related to timing issues in the travel of the electronic signals that will be registered as data points in a computer, it could be related to unknown geological effects. Or, of course, it could be that these neutrinos do beat photons by a few dozen nanoseconds as the fastest particles in nature. But I'm not betting on it."

I stand by my bet. It seems that timing issues in the detectors — that depend on near-perfect synchronization with GPS readings — will be the final explanation.

As with any new controversial discovery, there are good things and bad things to learn from this episode. Opinions are split as to whether scientists at CERN and OPERA acted properly by announcing their results so early. Should they have waited longer, making sure that their results were real before making them public? Or did they do the right thing telling the world of a puzzling result before confirming it?

In support of the latter, we should remember that scientists are under a huge amount of pressure to produce results: funding agencies want them, especially in expensive experiments, and the public wants them, to justify the money invested in research. When results brush with the wonderful, potentially debunking, or at least modifying, one of the pillars of modern science, the pressure and temptation is even bigger. Also, by bringing the results into the open, the scientists are asking for help from their colleagues, hopefully speeding up the resolution of the conundrum. (Although, of course, this could have been done within the scientific community through papers, conferences and workshops without bringing in the public media en masse.)

On the other hand, given the present widespread distrust with regard to science, the highly political manipulation of scientific results in the public arena (e.g., global warming and the theory of evolution, to the point that viable conservative candidates for United States president need to question both), and the level of general ignorance of scientific facts, this may not be the right time to bring out controversy within the scientific ranks. Even if controversy is the lifeblood of science (consensus is achieved as different hypotheses are analyzed and discussed in the face of experimental data), to make public declarations of revolutionary discoveries before confirmation can do more harm than good. As I wrote here before:

"The lesson here is simple: beware of quick, euphoric responses to preliminary scientific results, especially those that take aim at well-established theories. Although we must question to advance, we must also be careful before we blow the trumpets announcing the upcoming revolution."