The recent confirmation of the cosmic inflation theory ― a theory proposed over 30 years ago ― can be summarized as the universe surprising itself by what it learned about itself. Astrophysicists from the collaborative BICEP2 program just announced the discovery of gravitational waves, or actual evidence, supporting a theory which dictates that the early expansion of the universe occurred at a rate much faster than the speed of light for the first 10−36 seconds to 10−33 or 10−32 seconds following the Big Bang. “Detecting this signal is one of the most important goals in cosmology today,” said John Kovac, team leader of the BICEP2 coalition.
Why this matters
The principle of cosmic inflation serves as the link between quantum mechanics and general relativity, explaining questions such as: Why do we exist, and how did the universe begin? “These results are not only a smoking gun for inflation, they also tell us when inflation took place and how powerful the process was,” states Harvard theorist Avi Loeb.
What are gravitational waves?
Observing cosmic microwave background radiation, otherwise known as Big Bang residue, is a large part of what a cosmologist does; photon fluctuations in the spectrum represent areas of temperature variations, giving a key insight into the conditions of the early universe. Forming an understanding of such a long-ago time period is possible because of our understanding of light and its qualities.
Certain changes in color imply changes in wavelength, and subsequently, distance. For example, red wavelengths demonstrate that light waves are stretching because the object emitting them is moving away from the observer, and conversely, blue wavelengths demonstrate that the light-emitting object is approaching the observer. This is how cosmologists know that the universe is expanding. Since cosmic microwave background radiation is also a form of light, the radiation exhibits the same properties as visible light, implying that it’s also subject to the same kind of polarization.
The physical cosmology of the universe, above.
What the BICEP2 team actually observed was the cosmic microwave background radiation being altered in such a way that the only culprit could be gravitational waves. These waves create a distinct pattern by squeezing space as they travel. “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.
To a large extent, this observation confirms the existence of gravitational waves, one of Albert Einstein’s greatest predictions. Gravitational waves are ripples in time and space caused by massive objects; they carry information pertaining to that event.
How were they observed?
The team examined spatial scales on the sky spanning one to five degrees from the South Pole, an ideal location for observing faint microwaves, due its cold, dry, and stable air. To the team's surprise, the detected b-mode polarization signal was substantially stronger than expected, “This has been like looking for a needle in a haystack, but instead we found a crowbar,” said co-leader Clem Pryke. The data was then analyzed for three years in order to rule out the possibility that the dust in the Milky Way could be producing these results.
Story via Harvard.edu
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