A team of observational cosmologists may have found evidence that cosmic inflation occurred a fraction of a second after the Big Bang, a point predicted 18 years ago by Johns Hopkins University cosmologist and theoretical physicist Marc Kamionkowski.
At a news conference earlier today at the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass, researchers from the BICEP2 collaboration, a partnership between Harvard University and the California Institute of Technology, announced the first direct evidence for this sudden and vast expansion of the newborn universe. Their data also represents the first images of gravitational waves, or ripples in space-time. These waves have been described as the “first tremors of the Big Bang.”
The results came from observations by the BICEP2 telescope at the South Pole of the cosmic microwave background – a faint glow left over from the Big Bang. Tiny fluctuations in this afterglow provide clues to conditions in the early universe. This marker is part of a long-sought signature of events that occurred a breath after the Big Bang and has major implications for our understanding of the first moments of the beginning of the universe more than 14 billion years ago.
“It’s not every day that you wake up and learn something new about what happened one trillionth of a trillionth of a trillionth of a second after the Big Bang,” Kamionkowski said.
In 1996, Kamionkowski, then an assistant professor at Columbia University, and his collaborators theorized that the polarization pattern in the cosmic microwave background, or CMB, could be tracked geometrically. Since the cosmic microwave background is a form of light, it exhibits all the properties of light, including polarization. On Earth, sunlight is scattered by the atmosphere and becomes polarized, which is why polarized sunglasses help reduce glare. In space, the cosmic microwave background was scattered by atoms and electrons and became polarized too.
The team suspected that one unit, called B-modes, would appear reversed in a mirror image in a swirly pattern when observed through the CMB. BICEP2’s announcement is the first step in supporting that claim.
The magnitude of these B-modes sheds light on the new physics responsible for inflation, or the immediate expansion of the universe at its beginning, and in essence created a new field of study in cosmology.
Kamionkowski, a professor in Johns Hopkins’ Department of Physics and Astronomy since 2011, is considered one of the world’s leading theoretical physicists for his work in large-scale structures and the early history of the universe. He has spent much of his career researching astrophysics, cosmology and elementary particle theory. He said news of this discovery is exciting but “I’m trying to maintain a sober caution, because extraordinary results really do require extraordinary scrutiny, and the results that were announced have yet to be vetted by the outside community.”
Several predictions of cosmic inflation have been verified by a number of measurements over time, but primarily by NASA’s Wilkinson Microwave Anisotropy Probe, or WMAP, led by Johns Hopkins University astrophysicist Charles L. Bennett. He, along with cosmologist and assistant professor Tobias Marriage, currently co-lead the Cosmology Large-Angular Scale Surveyor (CLASS) project which will do similar work as the BICEP2 collaboration. CLASS is an instrument that will be located in Chile and is designed to test the inflation theory’s account of the first moments of the universe.
Institutions like Johns Hopkins as well as others in the astronomical community will continue to test and verify the BICEP2 findings. Meanwhile, Kamionkowski, who is not a member of the BICEP2 experiments team, was recognized as one of the theorists and participated in a host of events applauding the released results.
