It's probably an expanding, multidimensional equivalent of either a sheet of paper, a sphere or a saddle, according to astronomers at Columbia University, who report in the Feb. 20 issue of The Astrophysical Journal that they can shed new light on a problem that has stumped scientists for decades. Ari Buchalter, a graduate astronomy student, and David Helfand, professor of astronomy at Columbia, have devised a way to examine radio telescope measurements of distant galaxies to determine whether the universe is 'open' and will expand forever, 'closed' and will eventually collapse, or 'flat' and will attain some kind of equilibrium. They have studied 103 galaxies so far, and believe they can draw valid conclusions if they obtain results from 500 such galaxies, a project that should take another year or so. Theorists say the universe is flat.
Observers say it's open.
If we can get 500 of these galaxies, we should be able to rule in favor of one of them. Such a study would complement information being gathered by two satellites being launched to study this very question. The European Space Agency has approved a subsequent, more precise mission, the Planck Surveyor. Since the mid-20th century, astronomers have rejected the notion of a static, or Euclidean, universe, in which parallel lines extend infinitely without meeting. Instead, they now believe that space ultimately curves at great distances, and that parallel lines do touch each other, much as they would if drawn on the surface of a curved object.