Name: The discovery that could rewrite physics
Uploaded: 2014-04-01T15:10:50Z
Duration: 4 min 29 s
Description: On March 17, 2014, a group of physicists announced a thrilling discovery: the “smoking gun” data for the idea of an inflationary universe, a clue to the Big Bang. For non-physicists, what does it mean? TED asked Allan Adams to briefly explain the results, in this improvised talk illustrated by Randall Munroe of xkcd.

TED Tech Jun 12 Desktop Talks (5)

TED Tech Jun 12 Tablet Portrait Talks (3)

TED Tech Jun 12 Tablet Landscape Talks (5)

TED Tech Jun 12 Mobile Talks (7)

Don't miss out! Be one of the first to see our powerful new talks. 

Experience the TEDWomen conference from anywhere

TP TEDLive 9/28/23

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"

On March 17, 2014, a group of physicists announced a thrilling discovery: the “smoking gun” data for the idea of an inflationary universe, a clue to the Big Bang. For non-physicists, what does it mean? TED asked Allan Adams to briefly explain the results, in this improvised talk illustrated by Randall Munroe of xkcd.

The discovery that could rewrite physics

Talk details

About the speaker

Watch next