Nobel prizes surely await those who have confirmed the earliest moments of the universeby Philip Ball / March 27, 2014 / Leave a comment
The scale and development of the universe over time. ©BICEP2 2014
The discovery reported on 17th March by US scientists changed at a stroke our conception of the universe. It offered convincing evidence that, within a fraction of a second after the universe was born in the Big Bang, it underwent a period of very rapid growth called “inflation”. This produced a vast number of “gravitational waves,” a phenomenon predicted by Albert Einstein’s theory of general relativity. Evidence of these waves has never been seen before.
Finding evidence for either inflation or gravitational waves is a huge deal. But confirming both has left cosmology reeling and—barring some alternative explanation for the data, which looks unlikely—the discovery will merit Nobel Prizes.
According to Sean Carroll, an astrophysicist at the California Institute of Technology, the results supply “experimental evidence of something that was happening right when our universe was being born.” That we can find this evidence nearly 14bn years after the event is astonishing. It may also be a step towards solving one of the greatest and most profound problems in science—how to reconcile the two physical models of the universe: quantum physics and relativity. Achieving this would bring science closer to developing a theory capable of describing all physical phenomena.
The discovery was made by a team led by John Kovac of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts, using the Background Imaging of Cosmic Extragalactic Polarization (BICEP2) telescope located at the South Pole. It is a milestone in cosmology, and part of a story that has been playing out for almost a century.
In 1919, the British astronomer Arthur Eddington observed, from the island of Príncipe, the bending of starlight as it passed by the sun during a total solar eclipse. This confirmed Einstein’s prediction that gravity distorts spacetime, the fabric of the universe. General relativity also predicts that events involving very massive objects—an exploding star (supernova), say, or two black holes colliding—can excite waves in spacetime that travel like ripples in a pond. These are gravitational waves. Scientists were confident that these waves exist, but detection is immensely difficult because the distortions of spacetime are so small, changing the length of a kilometre by a fraction of the radius of an atom. Several gravitational-wave detectors have been built to spot distortions from passing gravity waves, but haven’t yet registered…