A discovery in the last week has turned physics on its head.     
    A team of scientists have said that they recorded subatomic particles called neutrinos travelling faster than light. No-one thought that was possible.
   
    It is a finding that could overturn one of Einstein's long-accepted fundamental laws of the Universe.
   
    The finding was made by researchers at Cern in Switzerland and Gran Sasso in Italy.
   
    The speed of light is a cornerstone in Einstein's theory of special relativity, which is what gives us the concept of causality: causes precede effects.
   
   
    Among the implications of this challenge to mainstream theory is the fact that it could mean time travel is possible, a hypothesis that has long convinced writers of science fiction.
   
    But the experiment has its sceptics. A physicist from the University of Surrey, Jim Al-Khalili, believes that the current consensus is correct and that the light-speed barrier is impossible to surpass.
   
    He has tried to pick holes in the methodology of the Cern researchers. So sure is Al-Khalili that they have made an error in their measurements that he has decided to defend the laws of physics by challenging the laws of social convention.
   
    Al-Khalili said: "If the Cern experiment proves to be correct... I will eat my boxer shorts on live TV."