Scientists at the world's largest physics lab think they may have proved Albert Einstein's theory of relativity wrong - by breaking the speed of light.
Experts at the European Organisation for Nuclear Research (CERN) in Switzerland believe they have clocked neutrinos travelling fast enough to shatter the central pillar of physics.
But they cannot quite believe it themselves, they say, because according to Einstein's famous 1905 equation, E=mc2, it is simply impossible.
"The feeling that most people have is this can't be right, this can't be real," said James Gillies, a spokesman for CERN.
Mr Gillies said the readings have so astounded researchers that they are asking others to independently verify the measurements before claiming an actual discovery.
"They are inviting the broader physics community to look at what they have done and really scrutinise it in great detail," he said.
Ideally they want someone elsewhere in the world to repeat the measurements, he said.
Scientists at the competing Fermilab in Chicago have promised to start such work immediately. Read More
Fermilab head theoretician Stephen Parke
"It's a shock. It's going to cause us problems, no doubt about that - if it's true."