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Mind-Bending Math & GamesGeometry

The Rope Around the Earth

Add one meter to a rope around the planet and it lifts 16 cm everywhere

Tie a rope snugly around the Earth, then add one meter. How high does it lift all around? A hair sounds right. Think again.

You'll find out

  • How high one extra meter lifts it
  • What a basketball and the Sun share
  • The assumption that changes it all

Why it matters

Your gut fails at planet scale. The same circle math sets the staggered starts of a 400 m race.

About 3 min6 interactive slides · 5 questionsLesson 21 · Zone 3

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