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World 7 · Time Across the Planet · 14 min · PRO

The longitude problem

How a clock found a ship

PRO · Clockwork & Time

World 7: Time Across the Planet is part of PRO

The first world of Clockwork & Time is free. PRO opens the other 24 lessons in 6 worlds — simulations, quizzes and all.

  • Time zones and the 15-degree rule
  • How GPS finds you with clocks
  • Relativity in your pocket
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  • Practice exams and certificates

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