The Large Hadron Collider

Scientists will this Wednesday "switch on" the most powerful particle accelerator ever built as they prepare for an epic journey back in time to the birth of the universe.

Newton's third law is that for every action there is an equal and opposite reaction. If we hold with the "Big Bang" theory that created the universe, we know at that moment matter was created. But so was anti-matter. What scientists do not know is what happened to the anti-matter. With the Haldron Collider, scientists hope to find out.

When activated, it is theorized that the collider will produce the elusive Higgs boson, the observation of which could confirm the predictions and missing links in the Standard Model of physics and could explain how other elementary particles acquire properties such as mass.

The machine has been called the largest scientific experiment in history and it straddles the French and Swiss border buried at a depth of 330 feet underground in 17 miles of tunnel.

It cost $5.8 billion to set up and with it some 80 physicists from around the world will hunt for signs of invisible "dark matter" and "dark energy".

The most powerful atom-smasher ever built could make some strange discoveries, such as invisible matter or extra dimensions in space, after it is switched on this Wednesday.

However the safety of the powerful collider has been debated for years.

Some critics fear that the Large Hadron Collider may actually exceed physicists' wildest calculations by creating a black hole that could swallow Earth, or spit out particles that could turn the planet into a hot dead mass, or release theoretical killer particles known as strangelets.

Scientists at CERN, the European Organization for Nuclear Research, say this is ridiculous.

Project leader Lyn Evans said: "Obviously, the world will not end when the LHC switches on."

"There is a huge army of scientists who know what they are talking about and are sleeping quite soundly as far as concerns the LHC."

And David Francis, a physicist on the collider's huge ATLAS particle detector said: "If I thought that this was going to happen, I would be well away from here."

Comforting words indeed.

The Collider
The collider basically consists of a ring of supercooled magnets 17 miles in circumference attached to huge barrel-shaped detectors.

When it is at full power, two beams of protons will race around the huge ring 11,000 times a second in opposite directions. They will travel in two tubes and speed through a vacuum that is colder and emptier than outer space.

Large detectors and cameras will collect data as the protons collide and 15 petabytes of data will be collected each year equivalent to a pile of CDs 12miles tall

No danger
Martin Rees, a physicist, has estimated the chance of an accelerator producing a global catastrophe at one in 50 million which is about the same odds as winning some lotteries.

A CERN team has also issued a report concluding that there is "no conceivable danger" of a cataclysmic event.

However, skeptics theorize that micro black holes produced by the collider might be trapped inside the earth's gravitational field and eventually threaten the planet.

Either way we find out this Wednesday.