扩张。。。
http://www.baltimoresun.com/news/maryland/bs-md-nobel-prize-riess-20111004,0,6622652.story?page=1
Riess was a 28-year-old post-doctoral student at the University of California, Berkeley, in 1998, when he made his seminal discovery. It was the year before he came to Hopkins.
Matt Mountain, director of the Space Telescope Science Institute, said Riess had been assigned to calculate the mass of the universe, said, "one of those boring projects you give to a grad student."
Boring, perhaps, but crucial to astrophysicists' attempts to calculate whether the universe would expand forever, or gradually slow, stop, and then begin to contract toward a "Big Crunch."
The number Riess came up with indicated the universe had a negative mass, Mountain said. It meant the expansion of the universe that was first observed in the 1920s, was actually accelerating. Something – a still-mysterious force dubbed "dark energy" – was pushing everything in the universe apart.
Mountain said the finding was as astonishing to scientists as it would be if he tossed his car keys into the air, only to watch them accelerate into the sky instead of fall back to Earth.
"Anybody else would have said, 'I've screwed up my calculations,'" Mountain said. Instead, Riess went back, checked his calculations, satisfied himself they were correct, and reported his astonishing find to the world.
It has since been confirmed by other researchers, using a variety of observations to reach the same conclusion. "It's gone from being a surprise, to being the new standard model," Riess said.
