A team of Oxford academics involved in the world's largest science experiment today has told the Oxford Mail: "We promise not to destroy the world".

Dr Alan Barr, of the University of Oxford's particle physics department, is one of 30 scientists from the city involved in the Large Hadron Collider (LHC) experiment in Geneva, Switzerland, which opponents have warned could end the world.

At 8.30am UK time today, scientists were due to switch on the giant machine, which is 100 metres underground beneath the Swiss-French border, to recreate conditions which existed fractions of seconds after the Big Bang when the universe began.

It will send two beams of particles in opposite directions at almost the speed of light around a tunnel 27km long, which has been likened to the London Underground's Circle Line.

The particles are due to smash together at four different places, one of which is at the Atlas project, where the Oxford scientists will be eagerly awaiting the results. They are among 150 British scientists involved in the project. Dr Barr, who is the UK physics co-ordinator, and another nine Oxford scientists will be operating machinery and analysing data.

They will then send it back to their department at the Denys Wilkinson building in Keble Road, North Oxford, where Dr Tony Weidberg and his team will be monitoring what is happening.

Dr Barr said: "This could lead to as big a change in physics as Einstein's discoveries did 100 years ago. This is the cutting edge of science and the opening of a new and exciting chapter. It is the first step in answering some of the most fundamental questions in science."

He and his team are working in an underground cavern half the size of St Paul's Cathedral awaiting the collision of the particles. He said: "We will be looking for signs of mass and understanding dark matter. We have the chance to completely change the way we understand physics. "

Some critics fear unleashing the dark matter could lead to black holes which rip the planet apart.

Dr Barr was quick to quash fears the experiment was dangerous, joking: "We promise not to destroy the world. The reality is that it's not at all possible for this experiment to end the world.

"These collisions have been going on for billions of years, although this will be the first man-made collision. The difference is that we are doing them in a controlled environment so that we can get science out of the results."

The experiment is being run by CERN (European Council for Nuclear Research), which Dr Barr says "takes safety very seriously".

HERE’S THE SCIENCE BIT: THE Large Hadron Collider (LHC) will accelerate two beams of particles in opposite directions around its 27km-long tunnel.

When they reach their maximum speed — 99.99 per cent the speed of light — they will collide at four points, producing thousands of new particles.

This is expected to recreate conditions similar to those a fraction of a second after the Big Bang when the universe began around 14 billion years ago.

Detectors within the collider will identify what these new particles are, helping scientists to understand how and why the universe developed as it did. Scientists know the Big Bang created space, time and matter, but have never before been able to understand why some particles are weighty and have mass while others are insubstantial.

They are also hoping to find out about what the universe is made of. About 96 per cent of the universe is "missing" matter which scientists have called dark matter but have never known what it consists of.