Two edits here. "14 billion years" and "13 billion years" refer to the same quantity: the time elapsed since the CMB  [Cosmic Microwave Background] was emitted. I bizarrely rounded differently in my head on the fly. In fact, the Big Bang took place about 13.798 +/- 0.037 billion years ago. 

(Aside: Those error bars should knock your socks off — determining the age of the cosmos with that accuracy by just looking at the night sky today is like you looking at me in this video and deducing my age in the video to within a couple of hours — that's insane!! Sherlock Holmes has nothing on cosmologists.)

The second edit is a cognitive slip that's all too common, and I could kick myself for perpetuating it: The "size" of the observed universe — the distance to the stuff that emitted the currently visible CMB 13.8 billion years ago — is not in fact 13.8 billion light-years. It's actually much larger — about 46 billion light-years — because the universe has continued to expand since the CMB was emitted. The stuff that emitted the CMB light we are just now seeing is thus much farther away.

"BICEP2 Press Conference"

Le 17 mars 2014, un groupe de physiciens a annoncé une découverte palpitante : la preuve irréfutable de la théorie de l'expansion de l'univers, et du Big Bang.

Pour les non-physiciens, qu'est-ce que cela signifie ? TED a demandé à Allan Adams d'en expliquer brièvement les résultats dans cette conférence improvisée, illustrée par Randall Munroe de xkcd.

La découverte qui pourrait réécrire la physique

Scientists have detected faint twists in the afterglow of the Big Bang, uncovering evidence of gravitational waves from the universe’s earliest moments. These subtle signals, found after three years of observations at the South Pole, suggest that everything visible may be just one bubble in a much larger cosmic landscape. The temperature differences in the ancient afterglow are just 10 parts in a million, offering key clues to how galaxies and structure formed. This discovery gives unprecedented support to the theory that our universe expanded at a blistering pace in its first instant.