GENEVA, Sept 10: International scientists celebrated the successful start of a huge particle-smashing machine on Wednesday which aims to simulate the conditions of the “Big Bang” that created the universe.

Experiments using the Large Hadron Collider (LHC), the biggest and most complex machine ever made, could revamp modern physics and unlock secrets about the universe and its origins.

The project has had to work hard to deny suggestions by some critics that the experiment could create tiny black holes of intense gravity that could suck in the whole planet.

Such fears spurred huge public interest in advanced physics ahead of the start up of the $9 billion machine, which proceeded smoothly on Wednesday morning.

Scientists in the control room at CERN, the European Organisation for Nuclear Research, broke into applause as they sent particle beams in both directions around the LHC’s 27-km underground chamber, drawing global praise.

“The worries that scientists had were nothing to do with being swallowed up by black holes and everything to do with technical hitches or electronic failure,” said professor Jim al-Khalili, a physicist at the University of Surrey, England.

“Now, after a collective sigh of relief, the real fun starts,” al-Khalili said. “No matter what we find, we will be unlocking the secrets of the universe.”

Eventually, the scientists want to trigger tiny collisions at nearly the speed of light __ an attempt to recreate on a miniature scale the heat and energy of the Big Bang, a concept of the origin of the universe that dominates scientific thinking.

The Big Bang is thought to have occurred 13.7 billion years ago when an unimaginably dense and hot object the size of a small coin exploded in a void, spewing out matter that expanded rapidly to create stars, planets and eventually life on Earth.

Lyn Evans, project leader for what experts are calling the biggest scientific experiment in human history, declined to say when CERN would start to smash particle beams together in the accelerator straddling the Swiss-French border.

“The LHC is its own prototype so it is difficult to judge how long it will take,” he said. “I think what has happened this morning bodes very well that it will go quickly.”

’DISCOVERY MACHINE’: Once the LHC starts up at full speed, it will be able to engineer 600 million collisions every second, with protons travelling at 99.99 percent of the speed of light.

Physicists hope such high-energy clashes will fill in the blanks of modern physics whose theories cannot yet fully explain gravity or mass.

The data recorded by the LHC -- measuring the location of particles to a few millionths of a metre, and the passage of time to a few billionths of a second -- will be transmitted to computers around the world for scientists to review.

They will be looking for how the particles come together, fly apart, or dissolve. The conditions in the LHC could also confirm or disprove the existence of the Higgs Boson, a theoretical particle named after Scottish scientist Peter Higgs who first proposed it in 1964.

Also referred to as the “God particle”, the Higgs Boson is thought to give matter its mass. It has never been observed.

LONG PROCESS: Wednesday’s start-up marked the start of a long and cautious commissioning process to check equipment and operational procedures before these collisions can get underway.

In a 27-kilometre circular tunnel on the Swiss-French border, parallel beams of protons will be accelerated to nearly the speed of light.

Superconducting magnets will then steer the counter-rotating beams so that strings of protons smash together in four huge laboratories, fleetingly replicating the conditions that prevailed at the “Big Bang” that created the universe 13.7 billion years ago.

Arrays of detectors will trace the sub-atomic rubble spewed out from the collision, looking for signatures of novel particles.

The first batch of protons was halted, sector by sector, to verify that monitoring systems and the steering magnets were working properly. Their speed was purposely slowed for the inspection process.

The clockwise beam completed this first test lap in under an hour, causing an eruption of joy and an outbreak of bubbly in the control room.

A test of the anticlockwise beam took place later and again the operation was problem-free.

“Technically, everything works the way it should work and the path ahead is very, very clear,” said Jos Engelen, the LHC’s chief scientific officer.

LHC Project Leader Lyn Evans, who has been working on the collider for 14 years, said he felt a wave of relief after the protons had completed their first lap so smoothly.

“It’s a machine of enormous complexity and things can go wrong at any time,” he said.

Messages of congratulations flooded in from CERN’s partners and rivals, including the legendary Fermilab particle physics lab near Chicago.—Agencies