The claim by scientists at CERN that they have discovered that subatomic neutrinos travel faster than light, if true, will upend the physics of more than the last 100 years and lead to a slew of exciting new theories about the way forward. And, not really paradoxically, the way backwards.
Danish astronomer Ole C. Romer first observed, in the late 15th century, that the speed of light is finite and the physicists A.A. Michelson and E.W. Morley strengthened that in their conclusion in the late 19th and early 20th centuries that the speed of light was constant (299,792,458 metres per second as measured in 1975), and that the speed of the observer made no difference to this. Albert Einstein then came up with his theory of Special Relativity which opened up vast new horizons, including time dilation. According to Einstein, time slows as speed increases. And, as he theorises that nothing moves faster than light, time stops when the cosmic speed limit is reached. Any object travelling faster than that, therefore, would mean it is travelling backwards in time. Sounds simple enough, but try imagining it.
But if the CERN physicists’ claim holds, does it mean that Einstein was wrong? Maybe not. If true, the question of how neutrinos outpace light leads to an obvious possibility in String Theory: that a fifth dimension somehow shortens the distance. This begs the question then of how many more dimensions may be added to the traditional four, including time. Quantum physicists, meanwhile, are already wondering whether they can get Quantum Theory to agree with relativity and about Einstein’s work on a Unified Theory of everything. The breaking of the light speed limit might just realise Einstein’s unfinished dream.