Einstein was wrong.

Einstein was right.

He was wrong about being wrong.

An astronomer from Louisiana State University said Wednesday that a new analysis of cosmic history cast doubts on Einstein's cosmological constant, the leading explanation for the mysterious force that appears to be pushing apart the universe.

But other astronomers said that conclusion itself was in doubt.

The astronomer, Dr. Bradley E. Schaefer, said his analysis showed that the force, known as dark energy, was not constant, as Einstein would have predicted, but was growing more violent as cosmic time went on.

"The cosmological constant does not look good," said Schaefer, who used flashes called gamma ray bursts as cosmic mileage markers to describe the history of the expansion of the universe.

In an interview Schaefer said it was a preliminary result. He presented his report at a meeting of the American Astronomical Society in Washington.

Several astronomers said it was Schaefer, not Einstein, who was wrong. His conclusion, they said, was undermined by mathematical and statistical flaws.

Einstein proposed the constant in 1917 as a way of explaining how the universe could be static despite the force of gravity. It was a sort of universal antigravity embedded in space. He abandoned that theory as a blunder when the universe proved to be expanding.

But in 1998, the cosmological constant gained new life when astronomers, using exploding stars known as Type 1a supernovas as cosmic mileage markers, discovered that the expansion of the universe appeared to be accelerating, as if a dark antigravitational force were indeed at work.

As Steven Weinberg of the University of Texas said, Einstein's biggest blunder was believing the cosmological constant was a blunder.

Dr. Donald Lamb, an astronomer at the University of Chicago, and others said Schaefer had been forced to his finding about the Einstein constant by his unfortunate use of a mathematical parameter called w-prime that is a measure of how fast the violence of the dark energy appears to be changing with distance in the universe.

At large distances, Lamb said, the parameter becomes mathematically meaningless, and theorists have dropped it. Moreover, he said, if Schaefer's analysis is valid, his results agree with Einstein's constant, within the measurements' uncertainties.

"It's not a meaningful discrepancy," Lamb said. "The result doesn't show Einstein was right. And it doesn't show he was wrong."