Galaxy study challenges cosmic-age estimate

摘要

Talk about a problem of astronomical proportions. Last month, researchers announced that they had determined the age of the universe to unprecedented accuracy (SN: 5/29/99, p. 340). Now, a report suggests that a cosmic yardstick used to calculate that age may be shorter than assumed. This could shrink the age of the cosmos by 2 billion years. The most recent study relies on the Very Long Baseline Array, 10 radio telescopes that span North America. Using this network, researchers have directly measured the distance to the galaxy NGC 4258—independent of any yardstick. "It's hard to go wrong when you're just doing high-school algebra to calculate a distance," says James R. Herrnstein of the National Radio Astronomy Observatory in Socorro, N.M.