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Science and Nature

Crash Course Astronomy

The Big Bang, Cosmology part 1: Crash Course Astronomy #42

Welcome to school without the classroom! Join host Phil Plait and discover everything there is to know about the cosmos.

The Big Bang, Cosmology part 1: Crash Course Astronomy #42

Season 1 Episode 42 | 13m 9s

Thanks to observations of galaxy redshifts, we can tell that the universe is EXPANDING! Knowing that the universe is expanding and how quickly its expanding also allows us to run the clock backwards 14 billion years to the way the universe began - with a bang.

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Crash Course Astronomy

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