Themis Bowcock writes: Early this morning, the physicists sat, with the media poised, waiting for two technical seminars from Cern to be delivered. There was only one question we all really wanted answered – would there be enough evidence to prove the Higgs particle had been discovered?
In London, John Womersley told us: “I can confirm that a particle has been discovered that is consistent with the Higgs boson theory.” In Cern, a spokesman said: “This is a preliminary result, but we think it’s very strong and very solid.” So there we have it. But what does the discovery of the Higgs actually mean to us? The answers lie in what the Higgs particle is and precisely what its role is in how the universe works.
About 50 years ago, physicists were faced with a conundrum in their theories of quantum mechanics, which describes nature at its most fundamental level. A successful theory called quantum electro-dynamics had been developed, which explained how particles of light and matter interacted. It was described as the “jewel of physics”, but while it correctly assumed that particles of light had no mass, it left a gap in our understanding of why otherwise similar particles were very heavy. For example we now know the particle of the force responsible for radioactivity is 100 times heavier than a hydrogen atom, but at the time we didn’t understand why. Two British scientists, Tom Kibble and Peter Higgs, decided to tackle this problem. They discovered that it is theoretically possible to make a particle without mass behave as if it did.
The Higgs theory suggested that nature, as it cooled after the big bang, froze into a unique configuration. The Higgs mechanism predicted that new particles came into existence as part of this freezing – “children” of the freeze. We now believe these Higgs particles are responsible for giving fundamental particles their mass and can leave them heavy or completely without mass; it’s as if the stickier a particle is to the Higgs, the heavier it is.
One of the great aims of modern physics has been to generate these Higgs particles. To create the right conditions for their study, huge accelerators such as the Tevatron in Illinois and the Large Hadron Collider in Geneva were built involving thousands of physicists and tens of thousands of engineers over decades, with funding from around the globe.
The Higgs particle is the first truly new particle that mankind has conceived – and now discovered – for millennia. Philosophers and scientists have reduced the world first to atoms, then fundamental particles, and then even the very quanta of the forces such as light.
The Higgs particle is not simply about the matter of which we are composed, nor about how it communicates (like light reaching our eyes from a distant galaxy), nor is it another layer of an infinite onion of smaller and smaller particles. It is the first part of the mechanism that tells us why the universe is the way it is today, why the stars burn the way they do and why light and matter are the way they are. Who among us can begin to imagine where this will lead in a century, let alone a millennium? [Continue reading…]