The Curious Cases Of Rutherford & Fry

The doctors continue their investigation into gravity, and answer Peter Fraser’s question: is dark matter a proper theory or just a fudge to fit existing 'proper' theories to otherwise inexplicable observations? Whilst scientists are pretty convinced our understanding of gravity is largely correct, there are still some significant gaps. Namely, given the way galaxies are observed to behave, around 85% of the matter that they think should be in our universe is missing. So where – and, as importantly, what – is it? Cosmologist Andrew Pontzen introduces the evidence from our observations of the cosmic microwave background, light leftover from the Big Bang, which indicate that dark matter exists. However, this evidence alone is not enough for science. Physicist Chamkaur Ghag is trying to find particles of dark matter here on Earth. Unsurprisingly, no-one is quite sure where these critters are hiding in the particle zoo of protons, neutrons, electrons, quarks, bosons, muons and the rest – or even what they look