A team of researchers that included researchers from U of T announced on Monday what has been hailed as one of the greatest physics discoveries in decades. Researchers who worked on the Background Imaging of Cosmic Extragalactic Polarization telescope (BICEP) may have found the “smoking gun” evidence for cosmic inflation. This evidence could confirm our picture of the universe in the first billionths of billionths of millionths of a second after the Big Bang.
U of T is one of 12 research institutions that collaborated on the BICEP2 telescope, where the data that revealed the gravitational waves were collected. U of T professor Barth Netherfield and phd student Steve J. Benton were both collaborators on the BICEP2 project, and the U of T is also collaborating on two successors to the project, the Keck Array and BICEP3.
The telescope was designed specifically to detect cosmic background radiation. It is located at the South Pole because the Antarctic plateau is one of the driest places on Earth. In most places on Earth, water vapour in the atmosphere will absorb microwaves, making it nearly impossible for scientists to detect the cosmic microwave background.
Current knowledge of the universe indicates that it expands at a constant rate, and seems to have done so for almost all of time. In the first fraction of a second after the Big Bang, however, theoretical physicists had predicted that the universe must have expanded much faster, which would cause “gravitational waves” — essentially shock-waves that rippled through spacetime.
Stanford professor Andrei Linde developed the current theory of inflation over 30 years ago. Albert Einstein, in his general theory of relativity, predicted the existence of these gravitational waves. However, there has been no firm experimental evidence to confirm either — until now. By looking at a surprisingly strong signal of what is called B-mode polarization (a pattern in the cosmic microwave background), an international team of researchers has now observed these gravitational waves that were caused by the inflationary period of the universe’s expansion.
Their paper, released on March 19 and freely available online, is the result of a detailed analysis of three years’ worth of results from the telescope. The Keck Array, another telescope and a successor to BICEP2, duplicated the finding, and the researchers now hope that other independent research teams will be able to confirm their discovery. A heartwarming YouTube video, now gone viral, shows the researchers breaking the news to the “father of inflation” Linde and his wife Renata Kallosh, also a noted theoretical physicist.
This discovery may also have major repercussions in other areas of physics research, since the evidence implies that inflation, a quantum phenomenon, produced gravitational waves. This experimental indication that gravity — like other fundamental forces of nature — has, on some level, a quantum nature. The so far persistently elusive unified theory of “quantum gravity” may in fact be possible.
