New evidence for Big Bang

Researchers in America believe they have found a signal left in the sky by the super-rapid expansion of space that must have occurred with the Big Bang. B-mode polarisation – as it has been named by the BICEP2 researchers – is a characteristic twist in the directional properties of Cosmic Microwave Background (CMB), waves of gravitational energy that ripple in the fabric of space time leaving an indelible mark on the sky. “Detecting this signal is one of the most important goals in cosmology today,” said Professor John Kovac, leader of the BICEP2 collaboration from the Harvard-Smithsonian Center for Astrophysics. “A lot of work by a lot of people has led up to this point.” BICEP2 used a radio telescope based at the South Pole to make detailed observations of a small patch of the sky, seeking out this residual marker for inflation. [caption id="attachment_37609" align="alignleft" width="400"] Gravitational waves from inflation generate a faint but distinctive twisting pattern in the polarization of the cosmic microwave background, known as a "curl" or B-mode pattern. For the density fluctuations that generate most of the polarization of the CMB, this part of the primordial pattern is exactly zero. Shown here is the actual B-mode pattern observed with the BICEP2 telescope, which is consistent with the pattern predicted for primordial gravitational waves. The line segments show the polarization strength and orientation at different spots on the sky. The red and blue shading shows the degree of clockwise and anti-clockwise twisting of this B-mode pattern. Credit: BICEP2 Collaboration[/caption] Inflation was first proposed in the 1980s to explain some of the aspects of the Big Bang theory that didn’t quite add up – such as why deep space broadly looks uniform wherever you look. The idea was that rapid expansion could have smoothed out any unevenness. “Inflation sounds like a crazy idea,” said Dr Jo Dunkley, who has been searching for a B-mode signal in data from the Planck telescope. “But everything we see today – the galaxies, the stars, the planets – was imprinted at that moment, in less than a trillionth of a second. If this is confirmed, it’s huge.” The researchers expect their work to now be subjected to intense scrutiny – particularly as an interaction of CMB light with dust in the galaxy could produce a similar effect – but they say they have carefully checked their data over the last three years to rule out such a possibility. Other experiments will now try to replicate the findings.