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SYFY WIRE Bad Astronomy

Crash Course Astronomy: How Far Is Far?

By Phil Plait
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Astronomy is weird. Everything we study is really, really far away. So far away really, that for most of history we didn’t know how far away they were. It was impossible to measure.

But then some Greeks decided to figure out how big the Earth is, and then how far away the Moon is, and the Sun, and before you know it (well, a few thousand years later) we’re measuring the distances to objects clear across the known Universe!

How? I’m glad I asked … because now I can answer, in this week’s episode of Crash Course Astronomy!

It’s always a good day when I can squeeze in a Fonzie reference. And poke fun at Star Wars.

I really enjoyed writing this and the past few episodes, because they lay the groundwork we’ll need for all the rest. Using what we know about light and about distances, the Universe unfolds before us. In the episodes coming up, we’ll leave the solar system behind and start to examine the cosmos around us.

Starting next week, we’ll be taking a Very Big Leap. Get ready, there’s a whole Universe we’ll be exploring from here.

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