Newswise — For decades, theorists have speculated that in its very first moments, our universe underwent a mind-bogglingly fast expansion that took it from the diminutive size of a proton to a vast expanse. Earlier this year, scientists announced a stunning development: what may be the first “smoking gun” evidence in support of this theory.
How certain is this result and, if it’s corroborated, what does it mean for our theories of how the universe works? Three leading theorists spoke recently with The Kavli Foundation about the implications of these results on our understanding of the early universe.
“To have the signal come in basically as big as it could be—bigger even—was just amazing,” said theorist Michael S. Turner, Director of the Kavli Institute for Cosmological Physics (KICP) and the Bruce V. and Diana M. Rauner Distinguished Service Professor at the University of Chicago. “We’re used to cosmology awing us, but this time it shocked us as well.”
Daniel Baumann, a lecturer in theoretical physics at Cambridge University whose research focuses on inflation and string theory, agreed: “My initial reaction was also shock and awe. I was intellectually prepared for these experiments, …but somehow in my gut I wasn’t prepared to have a signal that was as big as it actually was.”
“My concern at the moment is that it’s not yet clear whether or not they got it right,” said Paul Steinhardt, the Albert Einstein Professor in Science and Director of the Princeton Center for Theoretical Science at Princeton University. “They’ve definitely seen something. But deciding whether it’s due to gravitational waves produced in the early universe or due to some source in the foreground that’s between us and where the microwave background was emitted, that’s a key issue.”
More than half a dozen experiments around the world are now seeking to confirm BICEP2’s result in other frequencies and in other regions of the sky. The participants agreed that if these experiments find a similar signal and its shape matches what’s expected, that will be solid proof of cosmic inflation. In addition, the opportunity would exist to see subtle surprises in the signal that could lead to the discovery of new physics.
The complete discussion is available on The Kavli Foundation website: http://www.kavlifoundation.org/science-spotlights/theory-cosmic-inflation-bicep2