Physicists spent their weekends walking back media hype over an experiment that at first glance seems to disprove Einstein's famed theory of relativity. They preached dispassionate skepticism, but behind all that careful cynicism, there seemed a lot of hand-wringing.
News media widely reported results of an experiment at CERN, in Geneva, last week in which researchers shot particles called neutrinos toward another lab in Italy. Apparently the particles traveled just slightly faster than the speed of light. If you trust in Albert Einstein's theory of relativity, that shouldn't happen. As theoretical physicist (and ubiquitous science show host) Michio Kaku writes today in The Wall Street Journal:
According to relativity, as you approach the speed of light, time slows down, you get heavier, and you also get flatter (all of which have been measured in the lab). But if you go faster than light, then the impossible happens. Time goes backward. You are lighter than nothing, and you have negative width. Since this is ridiculous, you cannot go faster than light, said Einstein.
Does this mean it's time for a Back to the Future spin-off reality show? Well, nearly all scientists preached truck-loads of caution, including the researchers who presented their results. Until subsequent experiments back up these results, it would be foolish, they say, to throw out a foundational theory of physics. "This is quite a shake-up," Alvaro de Rujula, a theorist at CERN, told The New York Times. "The correct attitude is to ask oneself what went wrong." Kaku writes in The Journal that his "gut reaction" is "that this is a false alarm." He cites past examples in which physicists claimed to have disproved relativity only to have found simple errors in their experiments. The University of Surrey’s Jim al- Khalili tweeted, "If the CERN experiment proves to be correct and neutrinos have broken the speed of light, I will eat my boxer shorts on live TV."
But behind this defiant preaching of scientific processes and shorts-eating, there perhaps lies another motive for wishing away the results: throwing out relativity would mean a whole lot of work for scientists who would literally and figuratively need to re-write the book on modern physics. Michael Lemonick at Time says it would be "a complete upending of modern physics." "The implications could be huge. Particles that move faster than light are essentially moving backwards in time, which could make the phrase cause and effect obsolete." And Kaku says in the Journal, "Modern physics is based on two theories, relativity and the quantum theory, so half of modern physics would have to be replaced by a new theory. My own field, string theory, is no exception. Personally, I would have to revise all my theories because relativity is built into string theory from the very beginning." Sounds like a lot of overtime!