MOD Cosmos

Astronomers Confirm Einstein's Theory of Relativity and Accelerating Cosmic Expansion

ScienceDaily (Mar. 25, 2010
Scientists need to know how the formation of clumps of matter evolved in the history of the Universe to determine how the gravitational force, which holds matter together, and dark energy, which pulls it apart by accelerating the expansion of the Universe, have affected them. "Dark energy affects our measurements for two reasons. First, when it is present, galaxy clusters grow more slowly, and secondly, it changes the way the Universe expands, leading to more distant -- and more efficiently lensed -- galaxies.

After Growth Spurt, Supermassive Black Holes Spend Half Their Lives Veiled in Dust

"As a result of the violent, messy collision, the black hole also remains obscured behind a 'veil' of dust for between 10 million and 100 million years," said Priyamvada Natarajan, professor of astronomy at Yale and one of the paper's authors. After that time the dust is blown away to reveal a brightly shining quasar -- the central region of a galaxy with an extremely energetic, supermassive black hole at its center -- that lasts for another 100 million years, the team found.