Those of us educated in gentler times will be familiar with protons, neutrons and electrons. Today, however, things are more complex: the Standard Model of particle physics calls for 61 'elementary' particles, including the Higgs boson - or 'God particle' - and three 'flavours' of neutrino.
Neutrinos are strange things - even in the strange world of sub atomic particles. Billions of them buzz through us every second, but they have no charge and almost no mass - so how do you detect them? That's challenged scientists for many years and has led to increasingly sophisticated experiments. One of these - the IceCube - has detected 28 neutrinos with energies of more than 50TeV in a two year period. And scientists are excited by this, particularly because the neutrinos appear to originate from outside of our solar system.
Putting the experiment into context, the IceCube is a bit larger than the one you find in your gin and tonic. Located in the Antarctic, this particular 'ice cube' is 1km3 in volume and houses 5160 optical sensors, buried at depths ranging from 1.45 to 2.45km.
The question, however, is why search for neutrinos? Scientists believe the so called 'ghost particle' will help them to develop the Standard Model of particle physics - or maybe disprove it - and to better understand 'the meaning of it all'.
This is where the head really starts to hurt. Some aspects of String Theory - an extension to the Standard Model - call for extra dimensions beyond the four with which we are familiar. One of these extensions supports the concept of the tachyon - a particle which moves faster than light. And some have suggested that tachyons might be another flavour of neutrino. But here's where the head hurts even more: for something to travel faster than light, its mass has to be imaginary. Try finding that in a block of ice.
