Georgi and Glashow then went beyond the third dimension to come up with the SU(5) theory. After overcoming some conceptual problems, Georgi was able to use his theory to better describe the unification of forces.

According to the physicist, to understand his SU(5) theory, it is important to realize that electric charge is quantized and that this charge is conserved in any reaction.

But an immediate consequence of this theory, as Georgi points out, is that the decay of protons is inevitable. Physicists have spent many years hoping to observe such an event, he says, but to date, they have not been able to detect any evidence of proton decay.

Despite the excitement generated at first by his theory, Georgi says that within ten years, it became clear that protons do not decay as fast as SU(5) theory predicts. By then, scientists had reached a consensus that the phenomenon of proton decay was a credible hypothesis, though difficult to confirm.

But Georgi says he remains hopeful that proton decay will be detected.

"If proton decay is not much slower than the current bounds, it may still be seen, but it could be that we will never see it," he says. "That would close the one tiny experimental window on the world at these distances."

Colleagues Praise 'Pioneering Work'

Fellow physicists, while not necessarily agreeing with Georgi's theory, say that his work has been important in making strides towards unification.

Professor of Physics Cumrun Vafa says that though the exact form of the SU(5) theory is under debate, "Georgi's and Glashow's work is pioneering in the field and has greatly influenced the thinking of physicists on unification."

Georgi says that though there are limitations to the sizes of particles that can be studied, the work of particle physics is hardly complete.

The W particle sub-units, for instance, may lead to important new discoveries. The Goldstone Boson, Georgi says, is an "entirely new form of matter, because it is unlike anything else that we have seen."

He says he is hopeful that the Superconducting Supercollider (SSC), currently being built by the University of Texas, will provide a clue. The SSC will smash the W particle against another, neutral, particle, known as the Z particle.

"This is an unparalled challenge to particle physics explorers," he says.

Georgi says he hopes the research done at the SSC will be revolutionary. "[Physicists] will struggle to find landmarks in a new and completely uncharted region of our map," he says.

But Georgi is not sure where the impending revolution will lead. "That is like asking what happens after discovering America," he says.