Calculating the Incalculable.

Particle physicists have known the exact form and origin of the force that binds fundamental particles called quarks into protons, neutrons, and myriad other particles. Yet the theory of that “strongforce” is so complicated that researchers have struggled to perform many basic calculations, such as precisely accounting for the mass of the proton. But thanks to several key insights and the help of powerful computers, some theoretical physicists say they are on the verge cracking the theory of the strong force, which is known as quantum chromodynamics. They have already performed a first set of high-precision calculations, and within a few years they hope to make a slew of detailed predictions that will open new avenues of research, says Peter Lepage of Cornell University in Ithaca, New York. INSET: Monster Machines.