Quark Theory and Today's Supercomputers It's a Match

A simulation captures the potential energy between two quarks, which make up protons and neutrons. How do quarks behave? Quantum chromodynamics offers the theory but requires enormous computing power to do the math. L IVERMORE'S BlueGene/L, the world's most powerful computer, was designed for big jobs. Balancing a checkbook does not require a massively parallel supercomputer, but trying to discern what happened right after the big bang most certainly does. Quarks, the building blocks of all nuclear material, ran free for about 10-millionths of a second after the big bang. Then, as the universe began to expand and cool, quarks coalesced into protons and neutrons, held together by massless gluons. Since the big bang about 13.7 billion years ago, quarks have never been on their own, except for a few brief moments in a particle accelerator at Brookhaven National Laboratory and during the occasional cataclysmic cosmic-ray collision.