Surprising as it may seem, there are still some major barriers that are holding back the march of telecommunications. One of these barriers is Einstein’s universal speed limit – the speed of light – which applies to electrical currents in copper wire, beams of light in fibre optic cables and microwave communications with satellites. Light travels at approximately 200,000 km/sec in glass and at nearly 300,000 km/sec in air, but this is still far too slow for some telecoms applications. Fibre optic links can generate long enough delays to cause time-outs on high-speed data applications, and the quarter-second delay introduced by satellites is something that we see every day on our television screens when journalists are reporting from remote locations. Communications with probes in the outer reaches of the solar system are plagued by round-trip delays of up to a day, and there is simply no prospect of holding a telephone conversation with any extra-terrestrial civilization that may be orbiting a distant star.
Unless our current understanding of relativity theory turns out to be incorrect, the speed of light is one restriction that we are just going to have to live with. But recent developments at the Gran Sasso laboratory in Italy have raised the tantalising possibility that neutrinos may be capable of travelling faster than the speed of light. Admittedly, it’s only 0.0025% faster than light, but even that would be enough to prove that this fundamental speed limit can be breached. Another possibility is that Einstein’s speed limit is still valid, but the neutrinos have found a short cut through an additional dimension that we are not currently aware of. Either way, if these results prove to be correct, then faster communication may perhaps be a realistic aspiration.
Neutrinos have been described as the “bad boys of physics” by Professor Joao Magueijo of Imperial College, London. If any sub-atomic particles were going to be caught speeding, it was always likely to be neutrinos. However, these particles are so small that they very rarely interact with other particles, which makes them very difficult to work with. The experiments at Gran Sasso were conducted with extreme care, but there is still a high probability that the results will eventually be attributed to experimental error. However, if they do prove to be correct, and if travelling faster than light does not entail travelling backwards in time, then the race would be on to see how this new understanding of the physical world could be applied in the world of telecommunications.