Is Einstein wrong? Could it be that E doesn't equal mc2 ? Well it seems that physicists involved in the Opera experiment in CERN, near Geneva and the Gran Sasso Laboratory in central Italy may have detected particles travelling faster than the speed of light, Einstein's cosmic speed barrier. Well Einstein has been challenged before, nothing new there, and passed with flying colours each time as countless experiments tested his theories. Except maybe that damned quantum entanglement thing and its threat to special relativity - the locality versus non-locality debate; also black holes pose a problem for Einstein's theories, not to mention the big bang and the first moments of the universe (sounds a bit like what have the Romans ever done for us!). So what's the problem? Basically a bunch of neutrinos left a lab in Switzerland, made an underground journey to a lab 730kms away in Italy and arrived too early, 60 nanoseconds too early! And this isn't possible according to our current understanding of the universe and the laws of physics and undermines Einstein's special theory on relativity. However we should remember there are no sacred cows in physics. Now neutrino speed has been measured many times, and all results were as expected. An often used example is Supernova 1987A which erupted 168,000 years ago in the Large Magellanic Cloud. Neutrinos originating from this explosion were detected at the 'same time' (actually 3 hours later) as the visible light - so no faster-than-light speed in this case. Will physics books have to be re-written? Maybe hold back with the printing presses for now. It's possibly a measurement mistake. Remember neutrinos are very difficult to detect, very elusive, they have no charge, are extremely tiny and have very little mass. Because of this they rarely interact with matter or measuring devices. Just to give an idea of their relative size, if an atom was the size of our solar system, a neutrino would be the size of a golf ball! Now that's small! However with the latest and most sophisticated equipment in Gran Sasso they can be detected which resulted in this startling, to say the least, outcome. The data was checked and re-checked, scrutinized extensively and intensively, comprehensively examined for calculation errors, any errors. But no errors were found, to-date, so the scientists dropped the bombshell in September 2011. Physicists all over the world broke out in a cold sweat! If the results are correct what does this mean? Is was agreed for a hundred years amongst the world's scientists that the speed of light is a cosmic barrier. But maybe that's not so. After all, Tachyons are a class of particles that move faster than the speed of light, in theory. For now they exist only in the world of Maths. But maybe not for long more. So could neutrinos exhibit tachyonic behaviour? Well so many particles have first existed in the world of Maths and then progressed into the 'real' world of physics. So maybe. Of course the sheer size of the universe today also hints at the idea that the speed of light is not the ultimate speed limit of the universe, i.e. inflation theory and the extremely rapid expansion of the early universe. It is thought that the universe hadn't enough time since its beginning to expand to its present size and also have a uniform microwave background temperature if the speed of light is a cosmic barrier. It's also worth recalling the experiment in the United States in 2007, the MINOS experiment, which fired neutrinos between Fermilab near Chicago and a detector in Minnesota which resulted in a similar outcome to Gran Sasso, i.e. neutrinos seemed to be travelling faster than the speed of light. However their equipment was less precise so their uncertainties in the experiment were greater than in Italy so no significant conclusion could be made regarding the neutrino faster-than-light speed measured in Minnesota. Are the opera results the first experimental evidence of Brane cosmology. In Brane cosmology our visible four-dimensional universe is contained within a brane, which itself is contained within a higher dimensional (maybe 10 dimensions) space called the bulk which may have many four-dimensional branes. Interactions with other branes may cause effects not explainable in standard cosmological models. In Brane cosmology there is no Big Bang theory, but a Big Clap theory - the clash or collision of two branes which led to the creation of our universe. One theory on the Opera experiment is that the very high energies used to create the neutrinos could cause them to momentarily leave our brane and almost instantly re-appear which some scientists think could explain the faster-than-light speed problem. So is it an unknown measurement error or is the scientific community poised on a major breakthrough? Scientists await with bated breath!