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Longer cosmic ruler based on black holes

New method may improve extreme distance measurements

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10:26am, September 30, 2011

Astronomers have a new gadget in their cosmic toolbox that is capable of measuring distances to very faraway objects. The method uses active galactic nuclei, the bright, violent regions at the centers of galaxies, to gauge distances farther than existing cosmic yardsticks can reach.

Having such an odometer is crucial for understanding how space, time and matter behave at the scale of the whole universe, and could help solve mysteries such as the nature of the dark energy that is accelerating the expansion of the universe.

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