Series · 3 episodes · 5:06
Inventions that changed the world
The ideas behind machines, from the oldest simple tool to the press that spread books across Europe.
Play from episode 1- 1
1:46The law of the lever
A lever balances when force × distance from the pivot is equal on both sides. 100 N lifts 400 N, but it must push four times as far: the work is the same.
- 2
1:40Leonardo’s aerial screw
Leonardo’s 1480s aerial screw: a spiral linen sail about 5 m in radius. Momentum theory gives an ideal power of about 1.45 kW to lift a 75 kg person.
- 3
1:40How the printing press changed books
From hand-copied manuscripts to Gutenberg’s reusable metal type: how one invention made books cheaper and spread them across Europe.