The world could be a different place after Wednesday.
The world is waiting for the results of the particle acceleration experiment in CERN near Geneva. Its when the new Large Hadron Collider (LHC) will be used for the first time. It cost £4.4 billion to build it and its so big it straddles Switzerland and France.
According to some the experiment could create black holes that could destroy the planet, though the odds on that are highly unlikely. If you’re feeling particularly unlucky don’t book your holidays – unless its on the space shuttle!
The idea is to photograph two protons – a proton is a type of hadron, hence the machine’s name – that are smashing into one another at high speed, and get a picture of the resulting particle fragments – made up of various building blocks that scientists call bosons, quarks and leptons – that fly off in all directions.
Physicists have already identified 16 such particles. They call this the standard model.
But there is a problem with this model. Some particles have mass, others don’t. Its not neat and science likes things that are neat. Neatness generally implies they’ve got it right.
One physicist, Peter Higgs, from Edinburgh University, thought of a solution to the problem whilst trudging through the Cairngorms in 1964.
I’ll give an explanation as I understand it. Apologies to any real physicists! Feel free to correct me in the comments.
Think of Higgs walking through the Cairngorms, Summer 1964. Its Scotland so it’ll be raining or just stopped. Anywhere off the paths would be a field of mud.
Could it be that the sub-atomic particles are also in a field? And just like Higgs’ clothes, some of the sub-atomic particles – depending on where they ‘walked’ – got covered in mud, giving them mass?
If that was the case, then the Higgs field – as physicists now call it – itself must have a corresponding particle (the dirt particle in the field – its now called the Higgs boson) that provides the mass.
So this Wednesday when the particle accelerator is switched on, scientists hope that they can photograph the Higgs boson – or rather see the traces of it, in theory it should disappear too quickly for the cameras – for the first time.
Peter Higgs’ work was based on other scientists work on the predicted Goldstone boson. But his ideas have already earned him the 1997 Dirac medal, the 1997 High Energy and Particle Physics Prize, and the 2004 Wolf Prize in Physics and his portrait proudly hangs in the Scottish National Portrait Gallery.
If the LHC experiment finds evidence of a Higgs boson, Peter Higgs would almost certainly receive a Nobel Prize.
Its still all ‘ifs’ right now though. The LHC has not been tested; the experiment on Wednesday will be its first run. Its so large and costly that any tests would take months and cost more! Might as well run it and see if it works – if it doesn’t, well that’s a test! And its not at all clear how long it will need to run before the colliding protons create a Higgs boson that can be detected.
Most scientists think there will be a Higgs boson.
If there isn’t then all those physicists need to think of another explanation for the mass of sub-atomic particles.
Peter Higgs is almost eighty now. He thinks it might take a year to find his Higgs boson. Stephen Hawking has bet him £100 it will never be found. Still Higgs is confident and intends to be still alive when its found!: “There’s a conference next year in Glasgow to discuss the first results from the LHC, and I’ve been invited – dead or alive.”
This experiment may finally give physicists a true picture of how matter is composed, and a glimpse of what actually happened at the time of the Big Bang. It may even open more doors to string theory.
Its the most important scientific experiment of the 21st century. And depending on its answers, it could be one of the most important experiments of all time.