LONDON, September 10, 2008 (AFP) - The British scientist who gave his name to the so-called 'God Particle' said he believes it will be found by the world's biggest atom-smasher, which was finally fired up Wednesday.

'I think it's pretty likely,' said Professor Peter Higgs a few hours after the Large Hadron Collider (LHC) was switched at the home of the European Organisation for Nuclear Research (CERN) below the Franco-Swiss border.

'The way I put it is that if there isn't anything there, then it means I and a lot of other people no longer understand all the things we understand about these weak and electromagnetic interactions,' added the 79-year-old.

Physicists have long puzzled over how particles acquire mass. In 1964 Higgs, came up with this idea: there must exist a background field that would act rather like treacle.

Particles passing through it would acquire mass by being dragged through a mediator, which theoreticians dubbed the Higgs Boson.

The standard quip about the Higgs is that it is the 'God Particle' -- it is everywhere but remains frustratingly elusive.

Higgs, speaking in Edinburgh where he formulated his breakthrough theory 44 years ago, said the idea came to him over a weekend, rather than instantaneously.

'It wasn't a 'eureka' moment,' he said. 'It was a gradual realisation that stored in a different part of my memory was something which helped me to understand how to solve what I was worrying about at that time.

'When I came back on the Monday to work here the first thing I did was go and check various other papers to see if my recollection was correct and it would help me.'

The LHC, which has cost six billion Swiss francs (3.76 billion euros, 5.46 billion dollars) to build, aims at resolving some of the toughest enigmas in physics.

These include why particles have mass; an explanation for the strange 'dark matter' and 'dark energy' that account for 96 percent of the cosmos; and whether other dimensions exist in parallel to our own.