Scientists say they have extraordinary new evidence to support a Big Bang Theory for the origin of the Universe. Researchers believe they have found the signal left in the sky by the super-rapid expansion of space that must have occurred just fractions of a second after everything came into being. It takes the form of a distinctive twist in the oldest light detectable with telescopes.
"This is spectacular," commented Prof Marc Kamionkowski, from Johns Hopkins University.
"I’ve seen the research; the arguments are persuasive, and the scientists involved are among the most careful and conservative people I know," he told BBC News.
The breakthrough was announced by an American team working on a project known as BICEP2. This has been using a telescope at the South Pole to make detailed observations of a small patch of sky.
The aim has been to try to find a residual marker for "inflation" – the idea that the cosmos experienced an exponential growth spurt in its first trillionth, of a trillionth of a trillionth of a second.