PBS Space Time

What Caused the Big Bang?

Season 5 Episode 28 | 13m 12s

Every astronomy textbook tells us that soon after the Big Bang, there was a period of exponentially accelerating expansion called cosmic inflation. In a tiny fraction of a second, inflationary expansion multiplied the size of the universe by a larger factor than in the following 13 and a half billion years of regular expansion. This story seems like a bit of a … stretch.

Aired: 08/11/19

Rating: NR

Video has closed captioning.

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