Major Discovery: 'Smoking Gun' for Universe's Incredible Big Bang Expansion Found
Universe as it evolved from the big bang to now
Astronomers have found the first direct evidence of cosmic inflation, the theorized dramatic expansion of the universe that put the "bang" in the Big Bang 13.8 billion years ago, new research suggests.
If it holds up, the landmark discovery — which also confirms the existence of hypothesized ripples in space-time known as gravitational waves — would give researchers a much better understanding of the Big Bang and its immediate aftermath.
"If it is confirmed, then it would be the most important discovery since the discovery, I think, that the expansion of the universe is accelerating," Harvard astronomer Avi Loeb, who is not a member of the study team, told Space.com, comparing the finding to a 1998 observation that opened the window on mysterious dark energy and won three researchers the 2011 Nobel Prize in physics. [The Big Bang to Now in 10 Easy Steps]
A team led by John Kovac, of the Harvard-Smithsonian Center for Astrophysics, is announcing the results today (March 17), unveiling two manuscripts that have not yet been submitted to peer-reviewed journals. To understand just what the detection of an inflation "smoking gun" would mean, a little background about the universe's first instants is in order. Kovac's team will discuss the results in a news conference today at 12 p.m. EDT (1600 GMT).
The universe grows up
The brief and astonishing inflationary epoch transformed the infant universe from mere quantum fluctuations into something of macroscopic size, adherents of the theory say.
Beginning just 10 to the minus 35 seconds (roughly one trillionth of a trillionth of a trillionth of a second) after the universe's birth, the idea goes, space-time expanded incredibly rapidly, ballooning outward faster than the speed of light. (This did not violate Albert Einstein's theory of special relativity, which holds that nothing can move faster than light through space, since inflation was an expansion of space itself.)
Basic inflation theory has been supported over the years by several different space missions that mapped out the cosmic microwave background (CMB), the ancient light that began saturating the universe about 380,000 years after the Big Bang. (Before this time, the universe was a sizzling fog of plasma and energy too hot for photons to travel freely.)
While the CMB contains tiny temperature variations, it is, for the most part, strikingly uniform across the entire sky — a property that bolsters the inflation concept, researchers say.
"Why the cosmic microwave background temperature is the same at different spots in the sky would be a mystery if it was not for inflation saying, well, our whole sky came from this tiny region," Chuck Bennett, principal investigator of NASA's Wilkinson Microwave Anisotropy Probe (WMAP) mission, told Space.com last year. "So the idea of inflation helps answer some of these mysteries, and it explains where these fluctuations came from."