March 19, 2012

European researchers announced that they had again measured the speed of a subatomic particle that a September experiment suggested traveled faster than the speed of light. If it had, that would violate Einstein’s special theory of relativity, which underlies much of modern physics. Einstein’s theory of relativity says that nothing in the universe can travel faster than the speed of light in a vacuum, approximately 186,282 miles per second. That speed factors into all kinds of calculations, from estimates about the size and age of the universe to the radius of black holes. The research team that tried to verify the earlier result found that the particles, neutrinos, do not in fact travel faster than light. The team, called Icarus, measured the speed of neutrinos fired from CERN to a detector 453 miles away in Italy. Opera was the team that reported in September that its tests appeared to show neutrinos speeding faster than light. Doubts about the Opera results were heightened last month when researchers said they had found a flaw in the technical setup that could have distorted the experiment’s figures. The Icarus team’s results came from a trial run for a longer experiment planned to take place in April or May. The Opera team, too, will repeat its experiment, this time with the technical glitches ironed out. So, Einstein is still right, at least for now.