WASHINGTON — It is not often that one experiences a St. Patrick’s Day snowstorm of 8 inches; my favorite college basketball team (the University of Virginia Cavaliers) winning the ACC Championship and earning a No. 1 seed in March Madness; and a monumental announcement about the creation of the universe, all in 24 hours!
On Monday I watched the Harvard-Smithsonian Center for Astrophysics (CfA) news conference online, and I have to say that the announcement of the first direct evidence of inflation and gravitational waves is monumental in the understanding of the creation of the universe. It has taken me the whole day to digest the discovery and attempt to share it with you.
Let’s do a little cosmological background first in order to work our way up to Monday’s announcement.
Astronomers believe that the Universe was created in an event called the Big Bang that took place 13.8 billion years ago. We do not know what caused the Big Bang and the resulting creation of our universe to happen, or what, if anything, might have preceded it. The announcement did not shed any light on those questions.
Evidence for the Big Bang has been accumulating for decades and is strongly supported by observations of the residual light from the very early Universe called the Cosmic Microwave Background (CMB). The CMB is visible across the entire sky with specially designed instruments and detectors. It’s the echo of when light first appeared in the universe, 380,000 years after the Big Bang, and reveals the subtle fluctuations in the temperature and density of the very early universe that would ultimately lead to the creation of galaxies, stars, planets and us.
But another Holy Grail was still missing in our understanding of the Big Bang and what followed in those earliest moments of our universe. This is what the announcement was all about.
A theory called Inflation happened upon the cosmological scene about 34 years ago to help explain some problems with the Big Bang theory. Inflation theory holds that the newly created universe, just the size of an atom, underwent a tremendous and space-ripping expansion to the size of a football in an instant of time. Or, as described Monday in a news release by the California Institute of Technology, “the Universe expanded 100 trillion trillion times in less than the blink of an eye.”
The telltale signs of this period of inflation were predicted to be revealed as “gravi tational waves” buried in the CMB. Researchers needed to develop new instruments and detectors to find so called “B-mode patterns” in the CMB caused by gravitational waves. As explained in the CfA news release, “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 (Caltech/JPL).
Gravitational waves squeeze space as they travel, and this squeezing produces a distinct pattern in the cosmic microwave background. Gravitational waves have a “handedness,” much like light waves, and can have left- and right-handed polarizations.
“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,” said co-leader Chao-Lin Kuo (Stanford/SLAC).
The strength of the B-mode polarization signal was considerably stronger than had been expected, which is an indicator of how strong the inflation process was. As one team member put it, “we were looking for a needle in a haystack and found a crowbar.”
A small optical refractor telescope at the South Pole called BICEP-2 brought it all together for astronomers and researchers from 11 institutions based around the world. The observations were made at the South Pole because it is the closest place to space on Earth in terms of dryness and clear skies, necessary requirements to observe the CMB. Using detector technology developed by NASA, this team gathered multi-year observations during the six-month night at the South Pole, and in 2014 began three years of analysis and verification of results, culminating in today’s announcement.
Although this team is sure of its results, there must be independent verification and confirmation of the work by others. This is how science works, and as the late Carl Sagan said, “Extraordinary claims require extraordinary proof.” The announcement certainly meets Carl’s criteria, and if the work is confirmed, we may have witnessed future Nobel Prize winners.
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