After a few glitches are worked out, the Large Hadron Collider in Switzerland will be restarted and will accelerate two proton beams, moving in opposite directions, to velocities approaching the speed of light. At these speeds, mass and time are distorted and energy levels reach new extremes. When the time is just right, the two beams will be directed into each other’s path and create a collision, the likes of which have not existed since one trillionth of a second after the big bang, and it probably won’t destroy the world. “Probably?” you might reasonably ask. Put the question to any particle physicist and you will get the same responses. “It shouldn’t”. “It probably won’t”. “It is extremely unlikely”. Somehow, the vague lack of certainty in the answers is a little disconcerting. It means, by extension, that we will, in all likelihood, be alive to admire the new discoveries that the collider will bring forth, but we may not. It would feel a lot better to hear one of the geniuses involved with the experiment say “it just absolutely cannot and will not happen”. The problem is that scientists just don’t talk that way.
The concern is that the collisions created may create tiny black holes that will start swallowing all the proton parts around them until they increase in size enough to engulf the whole planet. Failing that, they may produce a theoretical, but as yet unobserved, material called strangelets that will behave in the same way. Both scenarios are almost unimaginably unlikely.
The safety of the LHC has undergone the most rigorous scrutiny imaginable. The scientists involved are well aware that their shot at a Nobel Prize is essentially gone if they destroy the world. The original safety assessment was done by a panel of CERN scientists in 2003. Despite the assessment that the collider posed “no conceivable threat” public concern remained, due primarily to the lack of absoluteness in scientific language. A second report was issued by a panel, convened by the management team at CERN, of a group of prominent physicist that were not working at the facility (in an attempt to insure absolute impartiality). The report, which confirmed the findings of the original assessment, was reviewed and endorsed by CERN scientists, as well as another panel of twenty independent experts and the executive committee of the Division of Particles and Fields of the American Physical Society. It was subsequently published in the peer reviewed Journal of Physics. At every stage the LHC was given a clean bill of health.
So, why the ambiguous and dodgy responses? It relates to the difficulty establishing anything to an absolute degree of certainty. Scientists submitting advanced research papers for peer review are well aware that it is impossible to prove any positive assertion, and so, are very careful to avoid overstating their case or overreaching in their conclusions. Ask any one of them if the sun will come up tomorrow and they will think for a second and reply “probably”.
The difficulty is in determining what amounts to an acceptable degree of risk. The cost benefit calculus is difficult when the cost is total annihilation. Scientists have calculated the chance of a catastrophe at CERN in the billions to one range, but there is certainly a price to pay, in both social and economic terms for not going forward. Consider this, equipment needed to do genetic splicing is readily available to anyone that wants it, and there are hundreds of amateur scientists with associates degrees in biology trying to create their own viruses in their garage. Maybe this is a more pressing and appropriate place to start the discussion.