Isochronism of the pendulum
Isocronismo del péndulo
- Date
- 1602 · confidence medium
- Place
- Padua, Veneto, Italy
- Credited to
- Galileo Galilei
- Field
- Cosmos & Earth
What was discovered
Galileo observes that the period of a pendulum's oscillation is almost independent of amplitude and depends on length, and proposes using it to measure time. He describes it in a 1602 letter to Guidobaldo del Monte.
The anecdote of the Pisa cathedral lamp (1583) comes from Viviani, written decades later and probably embellished; isochronism is only approximate for large amplitudes (Huygens found the truly isochronous curve, the cycloid).
What it led to
- Huygens's pendulum clock (1656)
- timing in free-fall and inclined-plane experiments
- Santorio's pulsilogia and pulse measurement