Review by Ron Cowen
Twelve years ago, astronomers studying distant, exploding stars made a discovery that irrevocably altered humankind’s view of the universe. Most scientists had assumed that the universe’s expansion, which began during the Big Bang, had steadily slowed due to gravity. But the astronomers found that the cosmos was instead expanding faster; gravity had somehow transformed from a cosmic pull into a cosmic push.
The unseen stuff supplying this mysterious push has come to be called dark energy. Together, dark energy and dark matter, the invisible material that scientists say must exist to explain galaxy formation, make up most of the universe. Left over is a measly 4 percent to form everything else, like people and planets.
In his aptly ti