Jonathan Amos at the BBC:
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.
The work will be scrutinised carefully, but already there is talk of a Nobel.
“This is spectacular,” commented Prof Marc Kamionkowski, from Johns Hopkins University.
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.
More here.