Einstein 1, neutrinos 0

The fact that the experiment gave the same result so many times suggested that one of two things was true: either the neutrinos really were speeding past light itself and heralding a new era of physics, or there was some fundamental flaw with the experiment, which was much more likely. It’s now looking as though the faster-than-light result was a fundamental flaw, and appropriately enough, it’s a flaw that actually helps to reinforce relativity rather than question it…

To understand how relativity altered the neutrino experiment, it helps to pretend that we’re hanging out on one of those GPS satellites, watching the Earth go by underneath you. Remember, from the reference frame of someone on the satellite, we’re not moving, but the Earth is. As the neutrino experiment goes by, we start timing one of the neutrinos as it exits the source in Switzerland. Meanwhile, the detector in Italy is moving just as fast as the rest of the Earth, and from our perspective it’s moving towards the source. This means that the neutrino will have a slightly shorter distance to travel than it would if the experiment were stationary. We stop timing the neutrino when it arrives in Italy, and calculate that it moves at a speed that’s comfortably below the speed of light.

“That makes sense,” we say, and send the start time and the stop time down to our colleagues on Earth, who take one look at our numbers and freak out. “That doesn’t make sense,” they say. “There’s no way that a neutrino could have covered the distance we’re measuring down here in the time you measured up there without going faster than light!”