THE 21st century is bringing astronomers more questions than answers, as evidence grows that the Universe consists mainly of utterly baffling stuff called dark energy. Though some astronomers remain unconvinced, new studies of the afterglow of the big bang make the strongest case yet for this idea.
“We only understand 3 per cent of the Universe,” laments Keith Grainge of Cambridge University, one of those involved. That small fraction is the ordinary matter found in stars and galaxies. Some of the rest is dark matter, which we can’t see but know must be there because of its gravitational effect. But that’s not all.…
