3 Americans Share Nobel Physics Prize

Researchers from Caltech and UC Santa Barbara will share the 2004 Nobel Prize in physics with an MIT professor for their studies of the so-called strong force, the powerful and mysterious energy that holds the nuclei of atoms together even as the positive charges on protons try to blow them apart.

The Nobel Foundation said today that the award will go to David Politzer, 55, of Caltech, David J. Gross, 63, of UCSB, and Frank Wilczek, 55 of MIT, for their development of the theory now known as quantum chromodynamics.

The foundation said the scientists' theory was a major step forward toward physicists' Holy Grail, the "Theory of Everything" that would use a single, simple set of equations to explain everything from gravity to the forces holding atoms together.

The trio explained the mystifying characteristics of the strong force, which holds quarks together to form protons and neutrons, two of the basic elements of atoms. The strong force grows very powerful as quarks are separated from each other, but paradoxically get weaker as they draw closer together.

The scientists also showed that when quarks are close together at very high energies, they act like free particles.

"They really helped us to understand how it is that quarks are bound together to make protons and neutrons," said physicist David Wark of the Rutherford Appleton Laboratories in England.