Neutrinos (not to be confused with neutron, neutrino means “the little neutral one”) defy Physics again by seemingly travelling faster than the speed of light. Even my students are asking the questions regarding these poorly understood particle.
The neutrino was postulated by Wolfgang Pauli (the same person responsible for Pauli Exclusion Principle) in 1930 to conserve energy, momentum and angular momentum in beta decay (see diagram). When I was still a secondary school student, I stumble upon this particle in some science non-fiction book. In the standard model, it is thought that neutrinos should be massless. But the missing solar neutrinos prompt scientist to rethink their model. Experiments carried out in the late 90s (during the time I was in university) observed that the different flavours of neutrinos oscillate from one flavour to another. These oscillations can only occur if neutrinos have mass. Our Physics lecturer at university tried to explain to us what it meant but even till now, I only have a vague understanding of these oscillations :-p
It will be interesting in the next few year to see if indeed travelling at speed higher than light in vacuum is really true. If so, we would have to tell our students that everything is possible and I can stop teaching Relativity!