GRAND FORKS, N.D. (AP) _ A University of North Dakota astrophysicist is part of an international team of scientists hoping to detect an elusive form of energy called dark energy.
Wayne Barkhouse has spent the past seven years creating computer software in preparation for the Dark Energy Survey, which began last month. He says that dark energy is ``the biggest puzzle in astrophysics in 100 years.''
Dark energy appears to have anti-gravity-like properties and is estimated to make up three-quarters of the universe. It hasn't been directly observed. Its existence is inferred from observations of other things in the sky.
The Dark Energy Survey aims to measure dark energy by measuring the expansion of the universe.
The project uses the world's most powerful digital camera, situated in the mountains of northern Chile.