Every other week Mallory Locklear, a graduate student at Stony Brook University’s Department of Neurobiology and Behavior, will take a look at Stony Brook-related research and science news.
In January, “Under the Microscope” reported on the research of professor Neelima Sehgal in the Department of Physics and Astronomy. Sehgal and her team were searching for what are known as primordial B-modes with the aim to bring our understanding of the universe within a split second of the Big Bang.
Then, on March 17, a team out of the Harvard-Smithsonian Center for Astrophysics announced they had indeed observed the elusive B-modes.
After the major announcement was made, Sehgal said via email, “Yes, very exciting! Still recovering!”
To understand the implications of these recent findings, however, let us back up some 13.8 billion years.
Scientists who have observed the farthest points of the universe have discovered that all areas of the universe, no matter how far apart, are incredibly similar.
For example, all regions of the universe are the same temperature.
For that to occur, it was theorized that though the universe is infinite now, at some point it was a small, dense, finite point where all things contained within the universe were co-mingling with each other. Then, just after the Big Bang, the universe underwent massive expansion, becoming the infinite universe observed today.
This theoretical expansion was dubbed inflation.
Scientists believed that this expansion would have left a lasting imprint on the universe and that the oldest light waves in the universe would carry this imprint. The light waves thought to be tagged with this evidence of inflation were named primordial B-modes and researchers like Sehgal have been hunting them ever since.
Using an instrument stationed in the South Pole called the Background Imaging of Cosmic Extragalactic Polarization 2, or BICEP2, the Harvard-Smithsonian team detected and measured waves from the oldest light in the universe and discovered markers of the sought after B-modes.
The researchers reported that their findings were significant at the five-sigma level.
When scientists report the statistical significance of their findings, whether it be through sigma or p-values, they are not saying how likely it is that their findings are true.
What they are actually saying is how likely it is that what they have found is due to random chance or to an actual effect.
So, for the results reported to be five-sigma, it would mean that if the primordial B-modes turn out to not exist, then there is only a one in 3.5 million chance that the researchers’ data would still be as strong as it is.
The higher the sigma, the better.
According to Sehgal, “If true, this is the first detection of primordial B-modes. If true, it is a very strong indication that inflation happened.”
If true, this would bring our understanding of the universe to within 10-36 seconds of the Big Bang. These findings will potentially help us understand the earliest moments of the universe and to better understand inflation itself.
However, the first step is to confirm the Harvard-Smithsonian findings.
Sehgal believes there is a 50/50 chance that these findings are real.
The B-modes were not observed where they were expected to be and were much larger than predicted.
Many researchers, including Sehgal, will be working to confirm these findings over the next year or two.
Working out of the Atacama Desert in Chile, Sehgal and her collaborators will be working to detect the B-modes with the Atacama Cosmology Telescope, or ACT. Proposed upgrades to the telescope will allow the team to observe the B-modes at the 40-sigma level, if they do indeed exist.
Regardless of what happens in the next year or two, the results have generated very excited buzz throughout the cosmology world.
Andrei Linde, one of the scientists that defined inflation theory in the 1980’s was videotaped when receiving the news of the recent findings. In the video, a flabbergasted Linde compares the news to placing an order saying, “Yeah, I ordered it 30 years ago. Finally it arrived!”