Name: 能改寫物理的發現
Uploaded: 2014-04-01T15:10:50Z
Duration: 4 min 29 s
Description: 在2014年3月17日，一群物理學家宣佈了一個令人振奮的發現：宇宙暴漲概念的數據證據，同時也是宇宙大爆炸的一條線索。對非物理學家而言，這是什麽意思？TED 邀請艾倫．亞當斯在這個即興演講中簡要地解釋這樣的發現，插圖由 xkcd 的蘭德爾．門羅繪製。

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"

在2014年3月17日，一群物理學家宣佈了一個令人振奮的發現：宇宙暴漲概念的數據證據，同時也是宇宙大爆炸的一條線索。對非物理學家而言，這是什麽意思？TED 邀請艾倫．亞當斯在這個即興演講中簡要地解釋這樣的發現，插圖由 xkcd 的蘭德爾．門羅繪製。

能改寫物理的發現

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