What the universe looked like 11 billion years ago
Travel back in time with one of the largest 3D maps of our universe ever created.
It's hard to imagine what the universe looked like 11 billion years ago, especially when I have trouble imagining what I want to do this weekend.
Scientists with the Sloan Digital Sky Survey are helping out by creating what they say is the largest 3D map of our universe. They did so by relying on ancient light emanating from quasars situated many eons away.
Quasars are extremely bright, remote objects that are often referred to as a "galactic nucleus" and emit incredible amounts of energy. A total of 14,000 quasars were tapped to create the map, and mapmakers used them in conjunction with interstellar hydrogen gas clouds that absorb light as it travels to Earth.
The detail in the map is based on wavelengths of quasar light that are absorbed by hydrogen gas clouds, revealing specific wavelengths of light and the distance between each. The result is a stunning 11-billion-year-old cosmological model.
"Here, we are looking at intergalactic hydrogen gas, which blocks light," researcher Anze Slosar, a physicist at the U.S. Department of Energy's Brookhaven National Laboratory in New York, told Space.com. "It's like looking at the moon through clouds--you can see the shapes of the clouds by the moonlight that they block."
Slosar unveiled the map over the weekend at the American Physical Society meeting in Anaheim, Calif. The Sloan survey is an ambitious program that's mapping the Milky Way, finding extrasolar planets, and trying to solve the riddle of dark energy.
This is merely the beginning. By 2014, around 140,000 quasars will help create a map 10 times larger than the current model based on observations from the Baryon Oscillation Spectroscopic Survey (BOSS).
What's the point of creating maps like these? Space.com notes that "the ultimate goal of such maps is to study how the expansion of the universe has changed during its history, which could shed light on the mysterious dark energy that seems to drive the accelerating expansion of the universe."