When God met the ghost particle

Life is full of surprises and ironies. For centuries, science and religion have often appeared to be on opposite sides of the argument about the nature of existence. In medieval Europe, challenging established religious beliefs could be a dangerous business. Galileo was forced to recant his belief that the Earth moved around the Sun. Giordano Bruno was burned at the stake for heresy. Fast-forward several centuries and science has acquired a rather curious vocabulary of its own. There is a 'God particle'. And now there is a 'ghost particle'. Science has given us a 'God particle' and now a 'ghost particle'. Well, if God exists, surely the ghost has to give Him company. The cosmic ghost hunter The latest twist in this unlikely story came this week when Belgian-born physicist Francis Halzen won the Nobel Prize in Physics for his pioneering work on neutrinos – tiny, elusive particles that have earned the nickname 'ghost particles' because they pass through matter almost without interacting with it. Halzen, 82, has spent decades trying to catch these 'cosmic ghosts'. His work was instrumental in developing the IceCube Neutrino Observatory, which uses the vast Antarctic ice sheet as a giant detector and has opened a new window into the universe. Trillions of neutrinos pass through our bodies every second. We don't feel a thing. That, of course, is precisely what makes them so fascinating. When God became a particle But the 'God particle' has an equally interesting story. The term is the popular nickname for the Higgs boson, the fundamental particle whose discovery at CERN in 2012 confirmed the existence of the Higgs field. The field helps explain why elementary particles have mass – and therefore why the universe can contain atoms, stars, planets and, eventually, people who spend their time arguing about the universe. The name, however, has nothing to do with theology. Nobel laureate Leon Lederman wanted to call his book about the elusive particle 'The Goddamn Particle', frustrated by how difficult it was to find. His publisher apparently thought the title a little too colourful and changed it to 'The God Particle'. The name stuck. Physicists have generally disliked it because it creates the impression that particle physics has somehow discovered God hiding inside the atom. It hasn't. Nor has Halzen discovered a ghost in the Antarctic ice. The unseen, seen differently That is the delightful irony. Science has borrowed the language of religion and the supernatural to describe things it is actually trying to explain through evidence, mathematics and experiment. And perhaps that tells us something about ourselves. Human beings have always been fascinated by the unseen. Religion has dealt with the invisible through faith. Superstition has populated the unseen world with ghosts, spirits and demons. Science takes another route: it asks whether the invisible leaves measurable traces. A neutrino cannot be seen directly. But if it produces a detectable signal, scientists can infer that it was there. That difference is crucial. Mystery gets a detector Science does not necessarily destroy mystery. Quite the opposite. Every answer seems to uncover another question. What is dark matter? What is dark energy? What happened in the earliest moments of the universe? And why does anything exist at all? The more we learn, the larger the unknown seems to become. Science doesn't eliminate mystery; it gives mystery a detector. And perhaps that is the most wonderful irony of all. The medieval world could punish people for questioning mysteries. The modern world builds enormous machines and buries detectors under Antarctic ice to chase them. The mysteries have survived. So have God and the ghosts – at least as words in our vocabulary. But the particles? They are real. And apparently, if you live long enough, one of them can even take you to Stockholm.