Text by J. Richard Gott The 2011 Nobel Prize in Physics has been
awarded to Adam Riess, Brian Schmidt, and Saul Perlmutter for
their discovery of the accelerating expansion of the universe.
It is one of the times when astronomers have won the Nobel Prize
in Physics. It is perhaps the most important scientific
discovery of the last quarter of the 20th Century. (The most
important scientific discovery of the previous quarter century?
Watson and Crick’s discovery of the structure of DNA.) What does
this discovery mean? Why is the accelerated expansion of the
universe so important? Einstein showed, in his theory of general
relativity, that gravity is due to the curvature of spacetime.
His theory has been tested many times. Most spectacularly, he
predicted that the Sun should bend light rays from distant stars
passing near it. This effect was observed in 1919 and Einstein’s
prediction was verified, whereas the prediction Newton’s theory
would have made was shown to be wrong. Einstein overturned
Newton. To use a sp