World's Biggest Atom Smasher - An Aerin view of the Cern nuclear research laboratoris. At the left can be seen the 25 thousands million electronvolt (25 gev) alternating gradient proton synchrotron, world's biggest atom-smasher, in the foreground the large experimental hall in which the high energy physics experiments are carried out and, to the rear of these, the huge ring building, 200 meters (656 feet) in diameter, embedded in the earth, in which protons are accelerated up to 99.3% of the speed of light. This machine is the joint realization of the twelve European founding member states of cern. February 3, 1950. (Photo by United Press International Photo).