... Observing . ... Gaping hole in universe . ... U niversity of Minnesota astronomers found a hole in the universe nearly a billion light-years across, empty of both normal matter such as stars, galaxies and gas, as well as mysterious "dark matter." ... The answer lies in dark energy, which became a dominant force in the universe very recently, when the universe was already three-quarters of the size it is today. ... Only registered members of Astronomy.com are allowed to comment on this article. ...