Why is it Dark at Night?

Have you ever wondered why you look up and see a dark sky at night?
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Minute Physics provides an energetic and entertaining view of old and new problems in physics — all in a minute!

Music by Nathaniel Schroeder

Thanks to Nima Doroud and Niayesh Afshordi for contributions and to Perimeter Institute for support.
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Created by Henry Reich Created by Henry Reich