If the public learned one thing about physics last year, it was that a particle had been found that might travel faster than the speed of light. Most people were probably vague about what the particle was, but they seemed to grasp the significance. The Universe's speed limit was in doubt, and anything might be possible. The result, announced by scientists at the OPERA neutrino experiment in Gran Sasso, Italy, may have been wrong, but the message conveyed about science was not. Late last month, following a vote of no-confidence in their leadership, OPERA's two top scientists resigned. Yet both men, along with the rest of the collaboration, can hold their heads high.
The vote and the resignations have not been officially blamed on the media circus over the faster-than-light neutrinos, which OPERA brought to public attention and was then forced to admit did not exist after all. But that is how they will be interpreted. And if the vote is portrayed as a referendum on how OPERA handled the situation, then scientists everywhere should think carefully about how they would have voted. What kind of science do they want?
The neutrino story is familiar to most researchers now, but here are the highlights. OPERA was measuring a beam of neutrinos coming from CERN, Europe's high-energy physics lab near Geneva, Switzerland. Contrary to everything taught in modern physics, the neutrinos seemed to be arriving 60 nanoseconds faster than light speed. A small sub-team of researchers responsible for the measurement spent months systematically checking OPERA's detector and could find no reason for the discrepancy.
When the smaller group shared their result with the full OPERA collaboration, it leaked to the Italian press. Faced with growing interest, OPERA's leaders — Antonio Ereditato and Dario Auterio, the duo who have now resigned — decided to go public with a seminar.
Physicists saw plenty of reasons to doubt OPERA's extraordinary claim, and Ereditato and Auterio did not disagree. Even as they presented the result, they invited their colleagues to comment, and encouraged others to try to reproduce their results. Within months, CERN had sent a new beam of neutrinos to Italy and a second experiment found neutrinos travelling at the expected speed. After a great deal of searching, members of the OPERA group eventually traced the discrepancy to a cable that was not fully screwed in.
“The message here is that scientists are not afraid to question the big ideas.”
Scientists both inside OPERA and out have since fretted about what such a high-profile misstep might mean for funding, reputation and the public's perception of science. In fact, OPERA's handling of the incident, at least publicly, was a model for how scientists should behave. Ereditato and Auterio acted responsibly when speaking publicly by sticking close to their data and avoiding over-interpretation. They shared their work with their competitors, and did their best to quickly address outside criticism. In the end, it was OPERA's internal checks that found the loose cable. When the error was discovered, physicists on the team wasted no time in publicly announcing the problem, along with others they had exposed during their review.
Broadly speaking, the media and the public seemed to grasp that this is the way science is supposed to work. Some Italian journalists aside, the press responsibly reported the initial result as simultaneously incredible and very possibly wrong. The public enjoyed the opportunity to question the world around them and learned a little physics in the process. Media coverage generally sided with the researchers for admitting they were wrong, and no one has called for funding to be cut.
Science can fall victim to human frailties. One researcher hoards her samples out of fear of competition; another doggedly promotes his hypothesis long after the data have falsified it; negative results are hidden because of competing financial interests. And the most frequent sin of all: questionable results go unchecked because it is in nobody's interest to check them.
The OPERA collaboration is not exempt from the human condition. Some collaborators believe that publication was rushed out of a desire to beat the competition. But OPERA nevertheless conducted itself openly and properly.
The no-confidence vote and resignations are a matter for the collaboration's internal processes, and have no bearing on the quality of the collaboration's science. But beyond OPERA itself, scientists should celebrate the way in which the results were disseminated and the findings ultimately refuted. The process was open and deliberate, and it led to the correct scientific result. In an era in which politics, business and celebrity fixate on spin, control and staying 'on message', OPERA's rise and fall make science stand apart. The message here is that scientists are not afraid to question the big ideas. They are not afraid to open themselves to public scrutiny. And they should not be afraid to be wrong.