EARTH: down to earth with Nobel Prize winner Adam Riess

The universe is repulsive, but in a good way. In 2008, while studying bursts of light emitted from exploding stars, newly named Nobel Laureates Adam Riess, Saul Perlmutter and Brian P. Schmidt discovered one of the most mysterious, yet prevalent, components of our universe: dark energy. The three were using the brightness and color from supernovae to determine the speed with which the universe expanded in the past, versus how fast it is expanding now. What they discovered completely transformed how astronomers view the evolution of space. The growth of our universe through time is accelerating. The culprit? Dark energy.

Astronomers and astrophysicists previously thought that the increasing amount of matter within our universe would cause the speed of space expansion to decrease over time. This assumed that all of the newly formed matter would have attractive forces that dragged and pulled at the edges of space. However, dark energy, which comprises approximately 70 percent of our universe, is in fact a repulsive force. And, although the universe has always been expanding, in recent years (which, in astronomical terms means in the past 5 billion years), it has also been accelerating.

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In September's issue of EARTH magazine, Adam Riess told EARTH about what dark energy is, the implications of his discovery (for which he won the Nobel Prize in physics, as announced this week), and the future of his research.

This story and many more can be found in EARTH magazine, available online at www.earthmagazine.org/earth/article/499-7db-a-4

Provided by American Geological Institute