The Golden Ratio, Excerpt...

THE GOLDEN RATIO: The Story of Phi, The World's Most Astonishing Number, by Mario Livio, (Broadway Books, New York: 2002), p.69 “In a surprising turn of events, in 1998 two groups of astronomers discovered that not only is our universe expanding (a fact already discovered by Edwin Hubble in the 1920's), but that the expansion is accelerating. This discovery came as a total shock, since astronomers naturally assumed that, due to gravity the expansion should be slowing down. In the same way that a ball thrown upward on Earth continuously slows down because of gravity's pull (and eventually reverses its motion), the gravitational force exerted by all the matter in the universe should cause the cosmic expansion to decelerate. The discovery that the expansion is speeding up rather than slowing down suggests the existence of some form of “dark energy” that manifests itself as a repulsive force, which in our present- day universe, overcomes the attractive force of gravity. Physicists are still struggling to understand the source and nature of this “dark energy.”