US scientists David J. Gross, H. David Politzer and Frank Wilczek won the 2004 Nobel Prize in physics on Tuesday for explaining how the basic building blocks of nature, quarks, interact to make a coin spin or build the entire universe.

"The discovery which is awarded this year's Nobel Prize is of decisive importance for our understanding of how the theory of one of nature's fundamental forces works, the force that ties together the smallest pieces of matter -- the quarks," the Royal Swedish Academy of Sciences' citation said.

The American scientists have brought physics one step closer to fulfilling a grand dream, to formulate a unified theory comprising gravity as well -- a theory for everything, the jury said.

Their work on the strong force acting between quarks inside the proton and the neutron within an atomic nucleus helps explain an everyday phenomenon like a coin spinning on a table, read the Academy citation.

Gross, 63, from the University of California, Politzer, 53, from the California Institute of Technology and Wilczek, 53, at the Massachusetts Institute of Technology made important theoretical discoveries "concerning the strong force, or the 'color force' as it is also called," according to the foundation.

The "strong force" is the dominant force inside the nucleus that acts between the quarks inside the proton and the neutron, the foundation said.

Their discoveries, published in 1973, led to the theory of quantum chromodynamics, or QCD.

The trio will receive a gold medal and share a check for 10 million Swedish kronor (US$1.3 million) at the formal prize ceremony held on Dec. 10, the anniversary of the death in 1896 of the prize's creator Alfred Nobel.

This year's award announcements began Monday with the Nobel Prize in medicine going to Americans Richard Axel and Linda B. Buck.

The Chemistry Prize will be announced on Wednesday, the Literature Prize on Thursday and the Peace Prize -- the only one not awarded in Sweden -- will be announced Friday in Oslo, Norway. This year's series of prizes will culminate in the announcement of the Economics Prize on Oct. 11.
 
(Xinhua News Agency October 6, 2004)