The world of physics has been shocked by a recent discovery of the CNGS project: neutrinos have overtaken the speed of light, challenging the pillars of modern science.
The speed of light, usually denoted by c (≈300,000 km per second), is the maximum speed (at least until a few days ago) at which all energy, matter and information in the universe can travel. In the theory of relativity c is strictly connected to space and time and appears in Einstein’s famous equation E=mc2
The CNGS (CERN Neutrinos to Gran Sasso) project consists in producing a neutrino beam at the CERN laboratory in Geneva and sending it towards the Gran Sasso laboratory (LNGS) over a distance of 732 km. A neutrino is an electrically neutral subatomic particle generated from a collision of protons, which produces pions and kaons. Pions and kaons are very short-lived particles, unlike the protons and the electrons that are the stable constituents of the matter surrounding us. Pions and kaons decay and the product of such decay are muons and neutrinos.
If you imagine this process occurring millions of times in the same moment you can have an idea of how a neutrino beam is produced. As neutrinos continue to travel in generally the same direction as their parent-particles, all that needs to be done is to focus pions and kaons in the right direction. The decay of these particles in a tunnel about 1 kilometre long creates the neutrino beam. Neutrinos interact very rarely with matter: this is clearly illustrated by the fact that there are 400,000 billion neutrinos from the sun that pass through our bodies every second!! This is a good thing if we think that these particles can travel underground to their destination (LNGS).
Up until 1999, neutrino experiments have been limited to a relatively short distance, but experiments conducted in Japan have shown that these particles have a “strange” behavior when covering a long enough distance.
To confirm this, a beam of neutrinos would be linked to another laboratory far from CERN, the underground laboratory of Gran Sasso. But nobody thought that this experiment would lead to such an unexpected result.
About 6 months ago it was discovered that neutrinos had covered the distance between CERN and LNGS in 2,4 milliseconds: it was 60 nanoseconds (0,000000006 s) faster than light!!
Scientists have been repeating their calculations for 6 months, expecting (or hoping for?) some mistake, but data confirmed the overtaking of the speed of light, and a few days ago the results were made public.
Some people moved criticism against this project, claiming that CERN had hurried to make the results public for fear that another research institute might beat them to the finish line.
But what is this discovery going to mean for humanity?
People’s imagination has started to run wild, thinking that it won’t be long before scientists invent a time machine. Unfortunately, this is impossible for the time being!
But, seriously, for bodies that travel at a speed faster than light scientists might formulate more general laws that might include the theory of relativity (which is still valid) as a specific situation in which bodies don’t travel faster than light; just like the Galilean transformation (that involves relatively slow objects and that is still valid after 400 years) is included in the theory of relativity as a more specific situation.
The following could be another consequence of this discovery: even though neutrinos don’t affect people, there might be an infinitely low possibility (but still a possibility) that in the universe something that affects people may travel at a speed faster than light, and because information travels at the speed of light, we could receive the effect before the cause. For instance, we might feel pain (i.e. the effect) before someone punches us (i.e. the cause/information, which is slower than the effect)!!
We just have to wait and see what happens!