Article excerpt
For a fleeting moment, the very fabric of the universe became a kind of hyperspeed spandex - stretching outward at perhaps 100 times the speed of light.
That concept, which describes the first trillionth of a second of the universe's beginnings, has gained wide acceptance among cosmologists. Now, scientists say they have discovered the first comprehensive, subtle signals from that cosmic growth spurt.
The discovery, announced Thursday, does not quite provide "smoking gun" confirmation of the concept, known as inflation. But scientists say they have detected wisps from the muzzle. With a few more years of data-gathering, they say they may be able to find the missing pieces that would clinch the case for a process widely held to have given the universe its initial "bang."
The new results represent a significant shift in efforts to uncover the origins and future of the universe, notes Lyman Page, a Princeton University physicist and member of the team reporting the discovery.
Cosmologists have long struggled to answer basic questions about the universe - its properties and composition, Dr. Page says. Now, scientists are adding an ability to "look back at these billionths of a billionth of a billionth of a billionth of a minute, ask detailed questions about the physics, and be able to answer them."
The new evidence comes from NASA's Wilkinson Microwave Anisotropy Probe (WMAP), a satellite designed to study the final whisper of the Big Bang - the primordial burst of energy widely held to have given birth to the universe. This whisper, actually low-level radiation, is known as the cosmic microwave background. The concept of inflation predicts that this whisper should leave behind signals from that event.
The WMAP team says it detected these signals from trends in relative brightness of bumps and dimples in the microwave background. These variations represent one of two kinds of polarized radiation - and the easiest type to spot - that inflation predicts. Ground-based and balloon-borne experiments have seen bits and pieces of this evidence. But WMAP has put a sky's worth together in one mosaic - an important milestone.
Launched in 2001, the WMAP satellite spent a year gathering data for a baby picture of the universe, which was built from subtle temperature differences in the microwave background. In 2003, the WMAP team decoded the information to yield the most precise estimates yet of the abundance of matter and energy, the universe's age, and its expansion speed. …
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