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How did a mariner's astrolabe help find latitude?

A heavy metal wheel does not look like a navigation computer. A mariner’s astrolabe nevertheless helped sailors measure the height of a celestial body above the horizon. Its weight and cutaway design helped it hang steadily in wind. That angle could inform latitude, but it did not by itself provide a complete position at sea.

3–7 min

Questions you could explore

  • What extra information connects an observed angle to a latitude?
  • Why would a beautiful instrument designed for land be awkward aboard a rolling ship?

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Engineering and inventions

How GPS finds you, and fixes its clock

Your phone can work out where it is by listening to signals from far above Earth. But turning a signal's travel time into a distance also creates a clock problem: the receiver must account for its own timing error.

12–15 min

How GPS finds you, and fixes its clock

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Engineering and inventions

Across an ocean inside a fiber-optic cable

A message crossing an ocean can travel through glass fibers lying on the seabed. The light inside, the layers around it, and the equipment along the route each solve a different problem.

8–10 min

Across an ocean inside a fiber-optic cable

Engineering and inventions8–10 minA message crossing an ocean can travel through glass fibers lying on the seabed. The light inside, the layers around it, and the equipment along the route each solve a different problem.

Engineering and inventions

Why does one pedal turn take you different distances?

Changing bicycle gears changes the relationship between your pedals and the rear wheel. The teeth on the chainring and sprocket help explain why the same turn of the pedals can produce a different distance along the road.

3–5 min

Why does one pedal turn take you different distances?

Engineering and inventions3–5 minChanging bicycle gears changes the relationship between your pedals and the rear wheel. The teeth on the chainring and sprocket help explain why the same turn of the pedals can produce a different distance along the road.

How did a mariner's astrolabe help find latitude? | Speech Topic | speaking.app