Turns out, the results were likely flawed, according to a growing scientific consensus some six months after the discovery was announced. Even so, here are 10 implications of faster-than-light travel.
The new findings threaten to overturn this trusted law. "According to relativity, it takes an infinite amount of energy to make anything go faster than light," said physicist Robert Plunkett of the Fermilab laboratory in Batavia, Ill. "If these things are [moving faster than light], then these rules would have to be rewritten."
The new finding raises all sorts of thorny questions. If the neutrinos really are traveling faster than light, then they should be time travelers. The particles could theoretically arrive somewhere before they departed. Physicists suggest such an ability, if it really existed, could be used to send neutrinos back in time to deliver messages.
But if something can travel faster than light, it can travel backward in time, according to the theory. In this case, an "effect" could travel back to a point before its "cause" had occurred — for instance, a baby swinging before he gets a push. Such a result would be scientific heresy, surely requiring some hasty rewriting of laws to make sure causality is preserved.
"Most of the theoretical structure that's been erected in the 20th century has relied on this concept that things have to go slower than the speed of light," Plunkett said. "As I understand it if you have anything traveling faster than the speed of light you can have things happening before their causes."
The status of the speed of light as the ultimate cosmic speed limit is the reason for its presence in the seminal formula. But if c is not in fact the fastest possible speed in the universe, and things can go faster, this may have to be adjusted in special situations. Perhaps the special speed of neutrinos deserves to win the title of ultimate speed limit instead.
But if the speed of light rule, and the theory of relativity are rewritten, this model too may need adjusting.
"One of the foundations of the Standard Model is special relativity," said Stephen Parke, head of the theoretical physics department at Fermilab in Batavia, Ill. "If you start tweaking with the foundation you have to start tweaking with the house on top."
String theory is incredibly difficult to test, and there is no proof that it's correct. But if the neutrino measurements are correct, some physicists say string theory may offer the best bet of explaining them.
Perhaps, some physicists have suggested, the neutrinos are not traveling along the straight line we thought they were, but instead were hopping into one of the extra dimensions predicted by string theory, and taking a shortcut to their destination. If they traveled a shorter distance in the measured time, then their actual speed may not have been faster than light.
Neutrinos are already understood to be oddballs. They are neutral, nearly massless particles that hardly ever interact with ordinary matter. They come in several kinds, called flavors, and they strangely seem to be able to change from one flavor to another. So it's possible that their faster-than-light abilities are unique features as well. (Above, a photo of the Gran Sasso Laboratory detector in Italy, the final destination of the neutrinos sent from the Swiss laboratory CERN.)
Yet if the new discovery is borne out, scientists may want to take a closer look at the theory of tachyons. [Read: What Would It Be Like to Travel Faster Than Light?]
This observation was a seminal achievement in astronomy, and won physicist Masatoshi Koshiba the Nobel Prize. [Gorgeous Supernova Photos]
Yet the new findings don't agree with this result. They suggest, instead, that neutrinos actually surpass the speed of light by 60 nanoseconds over 730 kilometers, which corresponds to 2 parts in 100,000.
It seems a revision of either the supernova measurement, or the neutrino findings, is in order. (Above is an image of a remnant of supernova 1987A encircled by a glowing gas ring known as the "String of Pearls.")
"Neutrinos are abundant in the early universe and if they behave differently, this affects calculations of the evolution of the early universe, nucleosynthesis and the seeds of structure formation," astronomer Derek Fox of Pennsylvania State University wrote in an email to LiveScience.
Furthermore, neutrinos are produced in the fusion reactions that power stars, so if these particles behave differently than thought, star models may need to be revised. (Above, an artist's conception of the history of the cosmos.)