Astronomers today announced an exciting discovery: the first direct evidence for what happened during the first few seconds or so of the birth of our universe. Since the notice last week that there would be a press conference today from the BICEP2 collaboration team, who run the BICEP2 telescope at the south pole, rumours quickly began to circulate that what was found was nothing less than the first confirmed evidence for cosmic inflation, when within the fraction of a second the entire universe we know of expanded outward 100 trillion trillion times (aka the Big Bang) from a point smaller than an atom about 13.8 billion years ago.
The new findings, announced this morning by the Harvard-Smithsonian Center for Astrophysics, finally provide confirmation for the cosmic inflation theory and an event which is almost too incredible to imagine. According to John Kovac of HSCA and leader of the BICEP2 collaboration: “Detecting this signal is one of the most important goals in cosmology today. A lot of work by a lot of people has led up to this point.”
Basically, the BICEP2 telescope, funded by the National Science Foundation, has obtained the first images of gravitational waves, which are ripples in space-time and the “first tremors of the Big Bang.” This was made possible by observations of the cosmic wave background, which is essentially the faint afterglow of the Big Bang, which can still be detected even now, billions of years later. The cosmic wave background is a form of light and has the same properties as all types of light, including polarization (think of polarized sunglasses which help to reduce the glare from the Sun in our atmosphere when the sunlight is scattered by the atmosphere and becomes polarized).
“Our team hunted for a special type of polarization called ‘B-modes,’ which represents a twisting or ‘curl’ pattern in the polarized orientations of the ancient light,” said co-leader Jamie Bock of Caltech/JPL.
“The swirly B-mode pattern is a unique signature of gravitational waves because of their handedness. This is the first direct image of gravitational waves across the primordial sky,” added co-leader Chao-Lin Kuo of Stanford/SLAC.
The gravitation wave signal found, after three years of examining the data, was stronger than expected. “This has been like looking for a needle in a haystack, but instead we found a crowbar,” said Clem Pryke, a co-leader of the BICEP2 team at the University of Minnesota.
During the cosmic inflation event, space itself was essentially ripped apart, expanding outward exponentially at an incredible rate. The whole concept is undeniably difficult to wrap one’s brain around, but at least now scientists have a better understanding of what occurred. Other evidence for cosmic inflation had previously come from the European Planck satellite, but the confirmation of the gravitational waves is considered to be the smoking gun.
The south pole is an ideal location to observe the very faint cosmic wave background as it is about the closest you can get to being in space while actually still being on Earth, due to the clear viewing conditions.
It is also being said that the discovery may even go beyond just learning what happened during the birth of the universe, but could also provide new evidence for a “multiverse” or parallel universes—the theory that our entire known universe is just one of countless other universes, like bubbles in an endless expanse of cosmic froth.
So just how significant is this discovery? According to Caltech theoretical physicist Sean Carroll, “Other than finding life on other planets or directly detecting dark matter, I can’t think of any other plausible near-term astrophysical discovery more important than this one for improving our understanding of the universe.”
Other physicists remain more cautious about the findings, such as theoretical physicist Matt Strassler: “Talking to and listening to experts, I’d describe the mood as cautiously optimistic; some people are worried about certain weird features of the data, while others seem less concerned about them … typical when a new discovery is claimed. I’m disturbed that the media is declaring victory before the scientific community is ready to. That didn’t happen with the Higgs discovery, where the media was, wisely, far more patient.”
Additional confirmation is always a good thing, of course, but even now it seems we can more clearly see what happened during the very first moments that our universe came into being.
Other links providing more detailed information on today’s announcement are here, here, and here. More technical information and the published papers are available here. The papers will be published in the journal Nature.