Are Secrets of the Universe Just About to Be Revealed? Scots Scientists Search for ‘God’s Particle’
By JAMES MORGAN GENEVA
THE INVISIBLE force which explains the nature of life, the universe and everything was first predicted by an Edinburgh scientist.
Now, a team of Glasgow University physicists are preparing to discover if he was right.
This week, in a cavern underneath the Swiss mountains, Chris Parkes and Saverio D’Auria watched as the particle detectors they designed and built were slotted into position in the Large Hadron Collider (LHC).
They are among 7000 scientists at Cern, a research centre near Geneva, aiming to discover what the universe is made of and how it came to be the way it is today.
By recreating the conditions one millisecond after the Big Bang, the LHC will allow them to search for the elusive Higgs boson, the “God particle”, which is believed to give mass to the the universe and everything in it.
Predicting the Higgs boson was a eureka moment for Edinburgh University physicist Peter Higgs.
He conceived of the “Higgs mechanism” while walking in the Cairngorms in 1964, and returned to his lab declaring he had had his “one big idea”.
Having failed so far to discover it, Europe’s leading nations have spent GBP5bn assembling the largest, most expensive science experiment ever built.
The LHC sits 100m below ground, in a 27km tunnel, straddling the Swiss-French border. Inside the circular tunnel, charged particles are accelerated to just less than the speed of light.
When these protons crash into each other, they will release high- energy particles, many of which have never before been observed.
“The exciting thing is that we have no idea what we will find, ” say Parkes. “It could be the Higgs boson, or it could be something else entirely. But whatever it is that gives matter its mass, we are certain to find it.”
If the Higgs shows itself, it would complete the “standard model” of physics and explain what the universe is made of and the laws which govern it. The challenge is to spot it in time. Following the collisions, the Higgs will only exist for a fraction of a second before it decays.
The LHC is designed to “photograph” the Higgs and other particles, using four enormous detectors. The largest is Atlas, a five-storey device which sits in a cavern the size of the nave of Westminster Abbey.
At its core is a barrelshaped detector module, designed and built by Dr D’Auria and colleagues.
“The challenge we face here is on the scale of the Apollo missions, ” said Dr D’Auria. “The difference is that the LHC is an international collaboration and I think it will go on to reveal far, far more about our universe than Apollo.”
A few miles along the tunnel, Chris Parkes is leading a second group of Glasgow scientists who are attempting to solve a different riddle.
Following the Big Bang, all matter should have been annihilated by its counterpart, antimatter. But, luckily for us, a small fraction has survived, forming the universe we know today.
“There seems to be a slight asymmetry between matter and antimatter, ” says Dr Parkes.
“Imagine you looked at yourself in the mirror 10,000 times and found that, once every 10,000, your reflection pulls a face at you. That one time represents all the matter we see in the universe – the “left overs” from the big bang.”
It’s a strangely appealing theory – the idea that the universe and everything in it, including ourselves, is made up of “leftovers” – the odd socks which stubbornly refused to partner up.
The hard part is proving it, but Dr Parkes is confident that we will soon know, with the help of another giant detector, known as the LHCb.
Inside the 20m-long machine, protons will collide at high energy, showering the walls with “beauty quarks” – and their antimatter equivalent.
Each collision is a tiny reconstruction of that moment milliseconds after the Big Bang, where some rogue matter gave antimatter the slip and gave birth to the universe we know today.
To photograph the particles, Dr Parkes and his Glasgow team have helped to design the Vertex Locator (Velo) detector – a series of silicon microwafers about the size of compact discs.
They cannot see the particles, but they can infer them by measuring changes in energy, velocity and momentum as they travel through the detectors.
After thousands of these collisions have been detected and measured, patterns will begin to appear – tiny discrepancies which will reveal the true nature of the asymmetry in our universe.
The answers are now tantalisingly close, although it appears the experiment will not begin this year as scheduled, due to an accident during testing.
At high pressure, a magnet came off its hinges, revealing a fault that may lead to months of repair work at various points of the tunnel.
In the meantime, the LHC continues to generate a great deal of hype and excitement.
MTV are considering filming a concert there. Cern was also visited by the actor Cillian Murphy, star of current Hollywood sci- fi blockbuster, Sunshine, in order to base his character – a particle physicist – on some of the scientists who are designing and building the LHC.
Had he spoken to Dr Parkes and Dr D’Auria, he would have learned that particle physicists are a very humble bunch, despite the grandeur of their pursuits.
At dinner parties, Dr Parkes is often too embarrassed to admit what he does for a living, while Dr D’Auria often introduces himself as a pizza maker.
If he discovers the Higgs boson, he will have no reason to be shy about it any more.
Stranger than fiction . . . the Large Hadron Collider
At 27km long, the Large Hadron Collider tunnel circuit is more than twice as long as the Glasgow Underground (10.4 km) and similar in length to London Underground’s Circle Line.
Protons hurtle around the collider 11,000 times a second, with the total energy of a Eurostar train travelling at a speed of 150km an hour.
The pipe in which the protons circulate is only a few degrees above absolute zero – colder even than deep outer space.
More than 7000 scientists from 80 countries work together at Cern, the European organisation for Nuclear Research.
Cern produces enough data every year to create a pile of CDs 20km high – without their boxes.
To exchange this data, the world wide web was created at Cern, by Tim Berners-Lee.
The UK’s contribution to Cern is GBP70m annually, meaning that every year, every tax payer contributes the price of a cup of coffee towards Cern.
Cern was also the setting for the Dan Brown novel, Angels and Demons, in which a scientist plots to destroy the Catholic church with an antimatter bomb.
Particles that make up ordinary matter
Electron
Responsible for electricity and chemical reactions
Discovered 1897
Electron neutrino
Little or no mass – rarely interacts with other matter
Discovered 1956
Up Quark
Protons made from two Up and one Down quarks
Discovered 1994
Doan Quark
Protons made from two Down and one Up quark
Discovered 1977
Virtual partices that carry force
Photon
Electromagnetic force (e.g. light)
Discovered 1900
Gluon
Holds together atomic nucleus
Discovered 1979
Z and W Bosons
Radioactivity (e.g. processes in the Sun)
Discovered 1983
Graviton
Accounts for gravity
To be discovered
Higgs boson
Imparts mass to particles
To be discovered
(c) 2007 Herald, The; Glasgow (UK). Provided by ProQuest Information and Learning. All rights Reserved.