Cheers OM. So they know exactly when that neutrino comes into being, so to speak? To the nanosecond? Sorry for harping on, I honestly haven't a clue about this, but I thought nothing could change a neutrinos direction or velocity and if they are to measure it's speed then they would have to know it's starting position. I'm amazed if they can do that. Please Register or Log in to view the hidden image!