Before you flick that switch…

21 February 2008

The world’s largest and highest energy particle accelerator, the Large Hadron Collider (LHC), is due to start experiments in May, and scientists hope it will answer some of the big questions in physics. But could these incredibly high energies change the nature of our reality instead of explaining it? Scientific experiments are always unpredictable, and with such a large experiment, there are many ways things could go unexpectedly wrong…Black holes are usually thought of as large, matter swallowing abysses out in the reaches of space, formed through the collapse of old stars. But Hawking’s work suggests that micro black holes could also exist, smaller than atoms, which interact rarely and rapidly decay into radiation. It is thought that a few are produced as cosmic rays impact the earth’s atmosphere, but the energetic collisions in LHC could produce them in large numbers. If they start to coalesce, they could grow into a massive black hole, sucking in the entire earth. But most scientists dismiss this, claiming they will decay into radiation before they can bind together. Far from being worried at the prospect of producing black holes, scientists at LHC are actually looking out for them. This is because they could provide evidence for the existence of extra dimensions in space and time, something that has long been postulated, but never confirmed.
Another possible doomsday scenario is the production of strangelets. Quarks are fundamental particles of nature which can come in different varieties, including top, bottom and strange, which combine to make atoms. Strange quarks are usually unstable and decay rapidly, but if a sufficiently large number of them are grouped together, they could theoretically make a stable particle, which would then convert all neighbouring material to match. This ‘ice-nine’ scenario, would result in the earth, and ultimately the universe, being consumed and turned into uniform material. Conditions at LHC have a small probability of creating these particles, though most consider it highly unlikely.
Strangelets have never been detected and theories suggest that if it were possible, they would have already formed in dense objects such as neutron stars.
Some scientists have even speculated that turning on the LHC might herald the first visitors from the future. In Einstein’s theories, time travel is possible, but only as far back in time as the first instance time travel became possible. The high energies at LHC could generate worm holes, folds in time and space which connect the present with the past or the future.
However, they are only likely to be big enough to allow a few particles to slip through, so any visitors will have to be fairly small. Scientists are nonetheless watching out for any rogue time travelling particles, as they should be easily detectable as energy discrepancies in collisions.These scenarios may sound like science fiction, but the true aims of LHC are no less incredible. Through high energy collisions, researchers hope to see the elusive Higgs Boson, sensationally termed the ‘god particle’, which could explain the origin of mass. It may also pave the way for a grand unified theory connecting the theories of astrophysics with the standard model of quantum mechanics, which explains the behaviour of the smallest known particles. This will give us a deeper understanding of our universe, if we manage not to destroy it in the process.