Astronomy Teams Agree Universe Won’t ‘Crunch’

The “big bang” will not be followed by the “big crunch,” say five teams of astronomers who used different techniques to gather evidence on the future of the universe.

Ruth Daly, a Princeton University astronomer, said, “It is quite clear now that the universe will expand forever.”

The astronomy teams, in effect, were trying to determine if there is enough matter in the universe to force it to one day stop its current expansion and start collapsing inward. Their findings, presented Thursday at a meeting of the American Astronomical Society, support the idea that there will never be a grand crunch.

Most astronomers now accept the idea that the universe began with a “big bang,” a moment about 15 billion years ago when a superdense point exploded in the most gigantic bang imaginable. It is believed that since then, all matter in the universe has been expanding outward. The controversy among astronomers is whether the universe is “closed” or “open.”

In a closed universe, the expansion would continue until gravity from the mass of matter canceled the outward force and the motion reversed directions.

But astronomers from Princeton and Yale universities, the Lawrence Berkeley National Laboratory and the Harvard-Smithsonian Astrophysics Institute reported Thursday that all of their studies show the universe is “open.” In effect, they found that the universe will continue to expand, and even accelerate, forever.

Neta Bahcall, working with a second Princeton team, said her studies of the largest structures in the universe--immense clusters of hundreds of galaxies--show the universe “has only about 20% of the mass needed to close.”

Others, including Saul Perlmutter of the Lawrence Berkeley National Laboratory in California, based their conclusion on studies of supernovae.