IB chemistry teachers who fret over how to teach students the correct use of uncertainties in their IA practical write-ups can have a field day over recent work from CERN in Switzerland. Scientists have released their experimental results for all other scientists to evaluate as it would appear that they have measured neutrinos travelling faster than the speed of light.

Comparable velocities:

Beam of muon neutrinos:  299,798,454 ms^-1

Speed of light in a vacuum: 299,792,458 ms^-1

Speed of sound at sea-level: 344 ms^-1

Usain Bolt: 10.4 ms^-1
(measured as an average over 100 m)

Neutrinos are extremely small sub-atomic particles. There are three known different types of neutrinos and they all are electrically neutral. There is some debate about whether they have mass. If they do possess mass then it is extremely small – one estimate puts it as one ten thousandth of the mass of an electron. Because of these properties they can pass almost completely unhindered through matter. Scientists at CERN have sent a beam of muon neutrinos from the super proton synchrotron accelerator at CERN in Switzerland through the Earth’s crust to the Gran Sasso Laboratory – a distance of 730 km. The neutrinos are detected by special ‘bricks’ containing photographic emulsion film with a combined mass of over 1,000 tonnes. From the simple equation of distance divided by time their velocity can be calculated. The experimental result is based on the analysis of 15,000 neutrinos detections. It appears that the neutrinos travelled faster than the speed of light but the increase is less than 0.01 percent. This raises the fascinating question as to whether their ‘strange’ result is due to the uncertainties associated with their experimental technique or whether Einstein has been ‘proved’ to be wrong and something can travel faster than the speed of light. The research is by reputable scientists who have looked at every possibility and claim that their result is well above the margin of experimental uncertainty. Because of the enormous significance if their findings turn out to be correct they have released their work for others to examine and find potential flaws. What is needed now is for independent researchers to confirm or refute their results in separate experiments – these can be currently be performed in two other neutrino beam laboratories – one in the USA and one in Japan.

One question that I would like to ask is “Could an experiment be devised so that the velocity of neutrinos and the velocity of light could be measured simultaneously under the same conditions?” If this is possible, then a direct comparison could be made. At the moment the neutrinos are passing through the solid Earth’s crust through which light cannot travel.

If the results are confirmed as correct then much of physics and chemistry (relativity and quantum mechanics in particular) will need to be rewritten as the equation E = mc² will no longer be absolute.