1. The LHC comprises four huge labs interspersed around a ring-shaped tunnel near Geneva, 27 kilometres (16.9 miles) long and up to 175 metres (568 feet) below ground.
2. Beams of hydrogen protons are accelerated in opposite directions to more than 99.9999 percent of the speed of light. Powerful superconducting magnets, chilled to a temperature colder than deep space, then "bend" the beams so that streams of particles collide within four large chambers.
3. The smashups fleetingly generate temperatures 100,000 hotter than the Sun, replicating the conditions that prevailed just after the "Big Bang" that created the Universe 13.7 billion years ago.
4. Swathing the chambers are detectors that give a 3-D image of the traces of sub-atomic particles hurled out from the protons' destruction. These traces are then closely analysed in the search for movements, properties or novel particles that could advance our understanding of matter.
5. In top gear, the LHC is designed to generate nearly a billion collisions per second. Above ground, a farm of 3,000 computers, one of the largest in the world, instantly crunches the number down to about 100 collisions that are of the most interest.
6. Peak LHC collisions generate 14 teraelectron volts (TeV), amounting to a high concentration of energy but only at an extraordinarily tiny scale. One TeV is the equivalent energy of motion of a flying mosquito. There is no safety risk, says CERN (the European Organisation for Nuclear Research).
7. Other LHC investigations include supersymmetry -- the idea that more massive particles exist beyond those in the Standard Model -- and the mystery why anti-matter is so rare compared to matter, its counterpart. Supersymmetry could explain why visible matter only accounts for some four percent of the cosmos. Dark matter (23 percent) and dark energy (73 percent) account for the rest.
8. Completed in 2008, the LHC cost 6.03 billion Swiss francs (five billion euros, $6.27 billion, at today's rates of conversion).
Hardon Collider danger
So what were the risks that have so many people edgy about when the LHC is fully operational? The first danger is black holes. Some physicists worry that high speed collision between particles at the energy levels offered by the LHC could create black holes. If you know anything about a black hole you know that it will absorb anything that comes near it even light. So the idea of one right here on Earth can seem frightening. However scientists who know about these things scoff. First they state that the black hole that could be probably created by the LHC would be infinitesimally small. On top of that microblackholes would not last long. They would quickly decay emitting a lot of radiation. So they would scarcely cause the destruction of the Earth.
The second danger is stranglets. There are theoretical particles that are similar to black matter but not quite. The concern is that these particles could be created by a powerful particle collider like the LHC. On Earth stranglets would essentially act like the Borg in Star Trek they would come in contact with normal matter and convert it into strange matter. This would continue an ongoing chain reaction with the new stranglets converting more normal matter into stranglets until the entire planet is one hot radioactive lump of strange matter. As you can see it is not a very pleasant way for the world to go. Fortunately we once again have the assurances of the experts. First the chances of creating stranglets decrease as energy use increases. Basically if older colliders did not make them it is not likely that the LHC will. The other bit of good news is that thermodynamics prevents them from being made if they are an order of magnitude cooler than their surrounding medium. This is once again something that is not likely to happen in the LHC. So while there are chances for something to go wrong the likelihood of it being apocalyptic is minimal.
http://www.huffingtonpost.co.uk/2012/07/03/top-10-large-hadron-collider-facts_n_1646549.html
http://en.wikipedia.org/wiki/Large_Hadron_Collider
http://www.universetoday.com/59156/large-hadron-collider-danger/
