WHEN PARTICLES COLLIDE sundaybriefing sundaybriefing It's 17 miles

Sunday Herald, The, Apr 13, 2008

IT IS one of the largest machines ever built, designed to detect some of the tiniest and most elusive particles in the universe. The Large Hadron Collider, a 17-mile long tube built 175m under the Swiss/French border, has been completed and, once switched on, it offers the hope that some of the most intractable problems of physics will be solved.

Edinburgh-based scientist Professor Peter Higgs has more than most riding on the results of the dollars-8 billion collider, as the LHC will either confirm or disprove the existence of the Higgs Boson, or God Particle. Once dubbed the "goddamn" particle, because of the difficulty physicists had in pinning down its existence and nature, it is the particle that is thought to give the universe its mass.

The physicist's "one big idea" came in the 1960s and aimed to explain why the stuff that makes up the universe - and planets, stars and humans - has mass.

He suggested there was a . eld that pervaded the universe, made up of particles called bosons. As particles move through this . eld, bosons stick to them and make them larger and heavier. A competition to explain the boson, commissioned by William Waldegrave, then the science minister, came up with the analogy of Margaret Thatcher moving through a cocktail party.

As she moves, she attracts hangers-on.

The LHC works by sending two beams of subatomic particles called "hadrons" - either protons or lead ions - in opposite directions around the accelerator. Scientists hope they can mimic the moments just after the Big Bang by colliding two protons - which will travel around the tunnel 11,245 times a second, 99.9999-per cent of the speed of light and with the force of an aircraft carrier sailing at 11 knots. After the collision, detectors the size of Westminster Abbey will pick through the subatomic rubble, searching for tantalising evidence of the Higgs Boson.

The experiments that are planned have already met with some controversy, with various apocalyptic scenarios predicted. A law suit has even been . led in Hawaii against the opening of the "big bang machine", claiming that safety precautions are insufficient and the world is sleepwalking towards its end.

The fear is that mini black holes formed during collisions could last long enough to turn into larger black holes, sucking the world towards Switzerland. Another fear is that so-called strangelets, quarks combined into strange forms, could be produced and turn Earth itself into strange matter.

The collision could even mark a "year zero" for time travel, as a pair of Russian mathematicians predicated that wormholes could be formed and, as time-travelling can only go back to the moment the machine was constructed, tourists from the future could become commonplace.

For a machine designed to test fairly arcane theories, the LHC has attracted massive public interest, with more than 50,000 people visiting during an open weekend.

The numbers involved are staggering: it will be cooled to just above absolute zero (-273C), 100,000 dual-layer DVDs' worth of data will be produced every year and, when two beams of protons collide, they will generate temperatures more than 100,000 times hotter than the heart of the Sun.

A spin-off computer system from the project has also been mooted which would be able to send the entire Rolling Stones back- catalogue from Britain to Japan in less than two seconds.

But the person most interested will be waiting anxiously in Edinburgh for the anticipated switch-on of the LHC in September. When Higgs was asked what he would do if the results proved the existence of the boson named after him, the 79-yearold professor said: "I shall open a bottle of something. It will be champagne - whisky takes a little more time to drink."