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How far away is the Sun?

Mnemorya · Astronomy & Space

课程2 章 · 4 关 · 约 20 分钟入门No background needed尚无评分

The sunlight on your face is eight minutes old. Four short levels on how we measured space — with a thumb, a late moon and a ship sent halfway round the world to watch a planet cross the Sun.

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你将学到

  • Explain why we always see the Sun as it was about eight minutes ago
  • Describe how parallax lets us measure distances we can't walk
  • Explain that a light-year is a distance, not a time
  • Explain why planets closer to the Sun have shorter years

章节

  1. Light takes timeYou know your street and your city. But how far is it to the next big house in the neighborhood — the Sun? Nobody has ever been there, and nobody has sent a tape measure. And yet we know its average distance to within a few meters.1 关
  2. Measuring the skyNobody has walked to the Sun or a star. So how do we know how far they are? With a thumb, a planet crossing the Sun and a lot of patience.3 关