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5 December 2013 11:26 am ,
Vol. 342 ,
Exotic, elusive, and dangerous, snakes have fascinated humankind for millennia. They can be hard to find, yet their...
Researchers have sequenced and analyzed the first two snake genomes, which represent two evolutionary extremes. The...
Snake venoms are remarkably complex mixtures that can stun or kill prey within minutes. But more and more researchers...
At age 30, Dutch biologist Freek Vonk has built up a respectable career as a snake scientist. But in his home country,...
Since arriving on the island of Guam in the 1940s, the brown tree snake ( Boiga irregularis ) has extirpated native...
An animal rights group known as the Nonhuman Rights Project filed lawsuits in three New York courts this week in an...
Researchers have been hot on the trail of the elusive Denisovans, a type of ancient human known only by their DNA and...
Thousands of scientists in the Russian Academy of Sciences (RAS) are about to lose their jobs as a result of the...
- 5 December 2013 11:26 am , Vol. 342 , #6163
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BOOMERANG Returns Glimpse of Early Universe
26 April 2000 5:00 pm
For months cosmologists have been eagerly awaiting measurements of the edge of the universe gathered by an antarctic balloon. A map published in the 27 April Nature gives the most detailed glimpse yet of the primordial universe, revealing the shape of the cosmos and the distribution of matter shortly after the big bang. The data support the prevalent view that our universe is "flat," but they cast doubt on other key assumptions about the early universe.
The 800,000-cubic-meter balloon carried a set of sensitive microwave detectors called BOOMERANG. In late 1998, the balloon swooped around the pole in 10 days, carried by air currents back to its launch site. BOOMERANG probed a large swatch of sky for fluctuations in the cosmic microwave background (CMB), a constant electromagnetic hiss that bombards Earth from all directions. This distant hiss is radiation leftover from the big bang.
The CMB can reveal the shape of the universe. According to relativity theory, the four-dimensional "sheet" of space and time that we live on can be curved. For years, astrophysicists have been figuring out the ways in which curved space-time might distort the images of distant objects, in hopes that astronomers would be able to tell which sort of space we live in--spherelike, saddle-shaped, or neither. BOOMERANG and other CMB experiments show that the fluctuations are not distorted as they would be in curved space.
Although astronomers expected this evidence for a flat universe, another bit of BOOMERANG data took them by surprise. Theory suggests that the ripples in the microwave background ought to exist on many different scales, each contributing a "peak" to the data. BOOMERANG saw a peak corresponding to roughly 1-degree-sized fluctuations and should have spotted a half-degree peak as well. It didn't. "That is extremely interesting," says University of Pennsylvania physicist Max Tegmark. "The mischievous side of me wanted that to happen."
The missing peak means that astrophysicists must tweak their models of how the universe formed. Precisely how they do this will depend heavily upon future results. Much of the BOOMERANG data has yet to be processed. And more will come after NASA launches a microwave-sensing satellite, MAP, this fall. New CMB peaks would tell scientists just how much invisible dark matter and ordinary matter there is in the universe and would help nail down details of the universe's first 300,000 years. "To me," Tegmark says, "this experiment really signifies the beginning of a new era."