NEW YORK CITY: In a discovery which could radically change the way we view the universe, a team of physicists say they've discovered evidence suggesting that the universe may have a "top" and "bottom." The proposal, by John Ralston of the University of Kansas and Borge Nodland of the University of Rochester, flies smack in the face of Einstein's theory of relativity, which posits that the universe is uniform in all directions. The new evidence indicates that the polarization, or direction of oscillation, of radio waves emanating from the constellation Sextans is different from radio waves emanating from constellations 90 degrees away -- something that could not happen if the universe was the same in every direction. Imagine the universe as a piece of wood and the radio waves as a saw blade. Because of the differing density, the blade cuts more easily with the grain of the wood than against it. Similarly, the faster-than-normal cycling radio waves could mean a difference in density, a sort of "grain" to the universe. The radio signals emanating from Sextans seemed to have a higher magnitude of polarization than constellations at 90 degree angles. This led the team to conclude that Sextans lies along a universal axis which runs north to south through the earth and towards the constellation Aquila, although their data did not permit them to say which constellation is in the north and which is in the south. The finding may also provide a challenge to the "Big Bang" theory that says that the universe was born and expanded in a completely symmetrical fashion.