One prevailing theory suggests that, in a fraction of a second, this embryonic universe expanded faster than the speed of light, increasing in size at a greater rate than it has in the 15 billion years since. Physicists believe that proving or disproving this theory will help them understand what existed before the big bang and why the big bang occurred in the first place.
Until recently, scientists had no way of putting this hypothesis, the “inflationary cosmological model,” to the test. Now a team of researchers at Columbia University, in collaboration with groups at other research institutions, has assembled a novel, high-powered telescope that will record relics from the universe’s moment of creation.
The 6,000 pound device, called EBEX, is now en route from its home at a Columbia laboratory to the site of its first test flight in Ft. Sumner, New Mexico. There, in mid-May, scientists will strap the telescope to a football-stadium-sized helium balloon that will carry it into the upper reaches of the atmosphere to photograph light from the big bang. If it is able to capture a specific signature in that light, called B-type polarization, it will be the first time any device has done so. “No one has ever seen this before,” said Amber Miller, professor of physics and Dean of Sciences, Faculty of Arts and Sciences at Columbia University. Should the telescope pass its first test, Miller’s team will send it back into the sky from Antarctica to snap pictures for two more weeks.
Much like a digital camera, the telescope takes photographs, but instead of capturing information in the form of optical light, EBEX “is designed to look at microwaves,” said Miller. The photons, or light particles, that the device picks up were emitted when the universe was 380,000 years old. They are part of a relic known as the cosmic microwave background, or CMB, cooled plasma leftover from the hot big bang that can still be observed today.
“Something special happened at that time,” said Miller. The plasma cooled enough to allow for photons, which had previously been bound up with electrons, to break free and travel through the universe. “As that light got away,” she said, “it carried with it an imprint, a photograph, of what the universe looked like before anything was formed.”
The B-type polarizations her team is looking for were created even earlier: by gravitational waves thought to have been generated during the big bang. “If we find the signatures of those waves, that tells us something about the type of expansion that took place in that early universe and what drove it,” said Miller.
The data her team gathers in New Mexico and, later, in Antarctica, will complement results recorded over the last year by a second camera, which sits atop a 17,000-foot plateau in Chile’s Atacama Desert. They are analyzing that data now and hope to publish it later this year. “Right now is an exciting time for our group,” said Miller.