For the first time in more than a year, protons should soon be whizzing around the world’s biggest atom smasher, the Large Hadron Collider (LHC), officials at the European particle physics laboratory, CERN, have announced. Within the next several hours, physicists at the lab near Geneva, Switzerland, aim to have beams of particle making complete laps through the 27-kilometer-long ring-shaped accelerator. That would get them back to where they were on 19 September 2008, when the LHC suffered a catastrophic failure just 9 days after researchers first fed particles all the way around it. “Keep your fingers crossed for us,” says Steve Myers, CERN’s director of accelerators and technology.
After researchers achieve stable circulating beams, they will likely try to accelerate them to an unprecedented energy of 1.2 tera-electron volts—only 1/6 of the LHC’s design energy of 7 TeV per beam. “The dream scenario is that people come to work Monday morning and find that we’ve broken the world record for energy,” says CERN spokesperson James Gillies.
Of course, the real goal is to smash those countercirculating protons together and then to raise the energy of those collisions. Lab officials can’t predict precisely when that will happen, but Myers says the goal is to obtain some collisions, even at low energy, before the end of the year.
Meanwhile, a group called conCERNed international announced today that it had filed a complaint with the United Nations in Geneva seeking to halt operation of the collider, which the group says may create mini-black holes that could destroy the world. “What we’re saying is that they should stop the machine until [physicists] do a better risk evaluation,” says James Blodgett, a conCERNed member from Albany, New York. Blodgett agrees that the risk appears low but says that the potential for triggering an apocalypse requires far greater margins of safety. Physicists argue, among other things, that astrophysical observations already show that even higher energy particle collisions involving cosmic rays do not create killer black holes. Some of the same critics filed unsuccessful lawsuits last year to try to keep the LHC from running, notes CERN’s Gillies. “Their arguments are as baseless as they were year ago,” he says.