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Why do running shoes have such complicated soles?

Turn over a running shoe and the sole looks like several inventions sharing one object. The layer touching the ground, the material above it, and the tread can serve different purposes. Bowerman’s documented shoe designs and Nike’s account of its waffle sole offer a specific way to investigate those choices, while keeping design intentions separate from measured performance.

3–7 min

Questions you could explore

  • Which layer would you examine to understand cushioning, and which to understand ground contact?
  • What would a patent establish that a controlled running test would not?

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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
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
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 do running shoes have such complicated soles? | Speech Topic | speaking.app