[UPDATE: June, 21, 2014; see note at bottom] In the scientific discipline known as cosmology — the study of the origin and evolution of our universe — finding “hard” evidence in support of theory is often hard to come by; scientists must look for subtle indictors or traces of cosmological forces that act over vast regions of space, or, ones that may have begun billions of years ago…back in the earliest moments of our universe, a split second after “creation”.
While cosmologists generally agree that our universe got started when something like a ‘Big Bang’ occurred some 13.8 billion years ago (either via an “exploding” singularity, or, via a massive quantity of energy entering our universe), it is what happened in the first moments after this event that has puzzled and intrigued cosmologists for many decades since this theory was posited.
According to the dominant model of cosmology, our universe doubled in size 60 times in a span of 10-32 seconds…that’s quite a bit less than one second, after which the myriad particles described by quantum physics embarked on their evolutionary (and probabilistic) trajectories. But without direct evidence, this model has remained an unproven theory.
Yesterday, a team of scientists at the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts announced their discovery of one of these subtle traces: minute ripples in the space-time fabric in the form of gravitational waves. According to the scientists, the pattern made by these ripples is the tell-tale sign of cosmic inflation, lending pretty definitive proof to the inflationary mode.
According to renowned physicist and early proponent of the inflationary model Alan Guth (who was not involved in this current research, but who was shown an early draft of the research paper prior to its publication):
“This is an astounding result. The observations are at a very high level of significance.”
The Inflationary Model of the Universe was first proposed by Andrei Linde of Stanford University in the early 1980’s (watch a short video of the in-person announcement).
A Telescope with “Muscle” Spots Pinwheel Patterns in The Cosmic Background
What is being called the “biggest discovery in cosmological physics in the past 20 years” comes from careful investigation of the cosmos-enveloping energetic remnant of this Big Bang: the cosmic microwave background (CMB; sometimes called the cosmic ‘black body radiation’). But teasing out subtle clues of our universe’s origin from this CMB sometimes takes a little muscle…In this case, the “muscle” was supplied by a small but powerful telescope called BICEP (Background Imaging of Cosmic Extragalactic Polarization) located on the South Pole of our planet (where there is little interference from city lights and pollution).
The BICEP telescope allowed scientists to discern random “pinwheel-like swirls” of polarized energy, known as B modes, in the CMB. The BICEP instrument allows scientists to map the orientation or polarization of the CMB as its constituent electric and magnetic fields fluctuate along different paths. In data collected from a small patch of the CMB during a two-year period (January 2010 and December 2012), the team was able to detect and verify these polarized B modes which are held by many in the physics community to be the “smoking gun” of the Inflationary Theory of the Universe.
The CMB detector was refined by a group of engineers from Cal Tech led by Jamie Bock who also developed the detectors for the Planck telescope launched in 2007. Results from this second telescope should help confirm the BICEP findings.
Gravity Waves and Quantum Theory: A Continuum of Cosmological History
According to Harvard cosmologist John Kovac (who is also one of the four principal investigators of the BICEP project):
“We believe that gravitational waves could be the only way to introduce this B-mode pattern.”
What’s more, the swirling imprints of these gravitational waves on the CMB appears to conform quite well with decades-old predictions asserting that gravity (on the smallest scale) should follow the same rules of Quantum Mechanics as the other three forces of Nature (electromagnetism, strong, and weak forces). During the ‘inflationary epoch’, what was once a minute quantum field also expanded along with the rest of space-time with the result that the fluctuations in this quantum field were magnified to an enormous scale — ultimately “seeding” the matter and energy density differentials that we see today as galaxies, galactic clusters and other large-scale cosmological features.
Consequently, the magnified fluctuation created corresponding fluctuations in the CMB (such as in the temperature of the CMB radiation); these fluctuations have helped cosmologists determine and distinguish “ordinary” visible matter form more mysterious forms like dark matter and dark energy. Now, with these recent findings, cosmologists have shown that inflation also magnified the minute gravitational waves into wavelengths billions of light years in size.
These finding, should they be fully confirmed, offer strong evidence for the continuity of cosmological evolution — from the first trillionth of a trillionth of a trillionth of a second after the Bang and extending even to the “death” of our Universe trillions of years hence. Further analysis of even more subtle flux patterns in the CMB will help cosmologist developed a far more detailed picture of the energy density of the nascent Cosmos.
The major findings were announced yesterday in a presentation at the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts.
[UPDATE: June 21, 2014] In just the past week, several prominent cosmologists have questioned the validity of the team’s results, claiming that the data was not properly vetted in the cosmology/astrophysics community. These critics contend that the pinwheel patterns spotted could be an artifact of the analysis and/or caused by interstellar dust. Read more on this brewing cosmic dispute HERE
Some Source material for this post (including quotes) came form the Science Magazine online article: ‘Glimpse of the Universe’s First Split Second Boosts Inflation Theory’ by Adrian Cho
Top Image: image: This NASA graphic shows the universe as it evolved from the big bang to now. Goddard scientists believe that the universe expanded from subatomic scales to the astronomical in a fraction of a second after its birth. (NASA/WMAP)