COSMOLOGY:
Astronomers See a Cosmic Antigravity Force at Work
James Glanz
An international team of astronomers who have used the brightness of distant exploding stars called supernovae to gauge how cosmic expansion has changed over time has reluctantly concluded that space itself appears to be permeated by a repulsive force. Gravity should have gradually slowed the outward rush of cosmic expansion, but as announced at a recent meeting, the dimness of the supernovae--pointing to unexpectedly great distances--implies that cosmic expansion has actually sped up in the billions of years since the stars exploded.