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Seeking Answers in the Darkness

November 19, 2010 - 12:56pm

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In 1998, two teams of astronomers studying distant supernovae made the remarkable discovery that the expansion of the universe is speeding up. This flies in the face of Einstein's theory of general relativity, which states that gravity should naturally lead to a slowing of the expansion, since over time it causes mass to attract other mass. Theorists offer two possible explanations for this phenomenon: either three-quarters of the universe is dark energy, which causes a type of anti-gravity, or gravity itself behaves differently on cosmic scales than Einstein thought it did.

To determine which assertion is correct, more than 120 scientists from 23 institutions in the United States, Brazil, Spain, Germany and the United Kingdom have come together to help design, construct and utilize a 570-megapixel camera which, when attached to the Blanco 4-meter telescope at Cerro Tololo Inter-American Observatory high in the Chilean Andes, will survey the deep reaches of the universe for insights into this essential question.

Fermilab, which is overseen by the Energy Department, has taken the lead in constructing the camera, which will ultimately be the key component of the Dark Energy Survey. Using components from SLAC National Accelerator Laboratory, the University of Michigan and institutions in Germany and Italy, they have spent the past 10 months constructing and testing the camera – a process you can view in the time-lapse above.

The camera, DECam, features the world’s largest shutter and filter, both standing nearly 5 feet tall, and light-sensitive photo chips, called CCD’s, which are essentially souped-up versions of the chips you’d find in a conventional digital camera. What sets these components apart is their ability to see red and near-infrared wavelengths at an unprecedented level. This allows the camera to capture the light of distant galaxies that are 10 million times fainter than can be seen with the naked eye, a capability that will ultimately enable scientists to peer through 300 million galaxies, three-quarters of the way back to the time of the big bang.

The project is set to begin capturing images in late 2011 and will continue for five years, in hopes of answering questions that will allow us to peer into the future of the universe and potentially redefine the way we think of physics.

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