NASA Dark Energy Announcement

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On Nov. 16, 2006, WKU Assistant Professor Dr. Louis-Gregory Strolger and three other astronomers announced they'd discovered that a mysterious force called dark energy has been a part of the universe for at least nine billion years.

"We've come to understand that it's the major constituent of our universe. It is basically comprising about 70 percent of the total energy density of our universe. The analogy we've been using is what if we didn't understand water, which makes up 70 percent of the earth's surface and that gives you an idea of how in the dark we are about dark energy," said Strolger.

Dark energy is a repulsive force that causes the universe to expand at an increasing rate. The astronomers used a Hubble space telescope to find out that dark energy has been around for awhile.

"Not only do we see dark energy in our current universe, we also see evidence for it in the early universe, in the first five billion years of our 14 billion year history," said Strolger.

Click on the thumbnail to view a larger diagram of dark energy:

The big question now is, is the amount of dark energy constant or changing? The answer to that question could determine the future of our universe.

"One of the big questions a few years ago is whether or not it will grow in strength with time and if so that can lead to a scenario where things will completely be ripped apart. It's a repulsive force so as it gets stronger over the size of the universe eventually galaxies will get ripped apart, stars will get ripped apart, planets and eventually atoms will get ripped apart...what we call the 'Big Rip'. We haven't completely ruled out that scenario but it's not the most likely scenario," said Strolger.

Astronomers also said the most likely scenario is that billions of years from now, the universe will become a very dark place. At that time, everything will be so spread out that even the closest star will be too far away to see.

The results announced Thursday are the culmination of a few year's work on data from the Hubble space telescope. The WKU Supernova Team, made up of a small group of students also inspect the Hubble's digital pictures and will present their recent discoveries at the American Astronomical Society meeting in Seattle, Wash., January 2007.

To find out a little more about dark energy click here.