Answer: If some CERN researchers are correct, it is no longer a law of the universe that the speed of light cannot be beaten. It’s just a guideline. But there’s a long way to go before we lock that result in.
The speed of light in a vacuum is 299,792,458 metres per second. Just under 300,000 kilometres per second. A constant speed. The speed of light in a given medium cannot be sped up or slowed down. Light will move at different speeds in different mediums (the speed of light through common glass is a mere 200,000 kilometres per second, for example, although light will rarely pass through enough glass to make this change detectable anything but the most sensitive of scientific instruments), but light in a vacuum is the fastest. Nothing could go faster than light in a perfect vacuum. This truth we held proven and self-evident since Einstein’s special theory of relativity in 1905.
The constant speed of light in a vacuum, and its position as a kind of speed limit for the universe, has been the basis of all physics since then. On the flip side, an awful lot of sci-fi has been based in pretending there is a way around it.
The time may have come to score yet another point for the predictive powers of sci-fi writers.
Researchers at CERN in Switzerland (also the location of the well-known Large Hadron Collider, although this result did not utilise the LHC) have announced that they have been able to measure a neutrino (tiny particles with no charge and less mass than an electron, let alone an atom) travelling faster than light. Or more accurately, they have been able to measure a beam of neutrinos travelling a distance of 730km in a time 60 nanoseconds (60 billionths of a second) more quickly than light can travel that distance, or about 0.00246% faster than light. To put it another way, if a photon of light raced one of these neutrinos over the 730km distance, the neutrino would have won by 17.96 metres. The CERN researchers believe the margin for error on the measurement was only plus or minus 10 nanoseconds.
These being proper scientists with a serious result to report, the CERN researchers have not rushed to judgment. Spokesman Antonio Ereditato said “We have checked and rechecked for anything that could have distorted our measurements but we found nothing. We now want colleagues to check them independently. The finding is so startling that, for the moment, everybody should be very prudent.” When asked to speculate on the consequences of the experiment he said “I just don’t want to think of the implications. We are scientists and work with what we know.” (emphasis mine).
It cannot be stressed enough what a change this would make to our understanding of the fundamental forces of the universe if it turns out to be true and correct. If there is a means to accelerate something with mass (like a neutrino) to go faster than weightless light, it reopens countless possibilities as ideas rejected as unworkable for violating the theory of relativity once again become worth examining. That said, people running around saying “Einstein was wrong!” are way over the top. 100 years of physics experiments have produced results agreeing with Einstein. Even if there turns out to be an exception to relativity, relativity has still proven to be a perfectly accurate description of the universe’s behaviour in every other circumstance.
There are definitely reasons to be cautious. Two German researchers claimed in 2007 (and still claim) to have proved the speed of light could be broken, but on examination the general belief of the scientific community was that their experiment did not do what they claimed it did. It is quite common for major “breakthroughs” to be announced and then proved flawed. Your author can think of a dozen or so very subtle reasons that would introduce a measurement error to either the travel time of the neutrinos or the distance they were thought to have travelled, to say nothing of programming errors in the devices used. Now, if your author can think of these things, the CERN scientists almost certainly did, but the point is that there’s a lot of i’s to dot and t’s to cross before we can start dreaming of Star Trek-style faster than light travel, and there’ll be a lot of physicists, engineers and programming experts out to make a name for themselves by being the person who discovers the hole in the CERN experiment. If you were into gambling, you’d put your money on a flaw being found. But if a flaw isn’t found, working out how this happened how to fit it in with everything else we know about the universe is going to employ a lot of physicists for decades. New job stimulus!
