The Longitude Problem
Eight facts, each caused by the last — from a fleet wrecked on the rocks to the satellite in your pocket.
- In 1707 a British fleet ran onto the Isles of Scilly and as many as two thousand men drowned.
In 1707 a British fleet ran onto the Isles of Scilly and as many as two thousand men drowned. The navigators knew exactly how far north they were, and had no reliable way to know…
- Parliament put up a fortune for a solution.
Parliament put up a fortune for a solution. Longitude is really a question about time: how far around the world you are is the gap between local noon and the hour back home.
- So the prize came down to building a clock that could hold London time on a rolling deck.
So the prize came down to building a clock that could hold London time on a rolling deck. Every accurate clock then made kept time with a pendulum, which a ship's motion renders…
- A self-taught Yorkshire carpenter spent forty years on it, bonding two metals into a strip that bent with temperature to cancel out its own expansion.
A self-taught Yorkshire carpenter spent forty years on it, bonding two metals into a strip that bent with temperature to cancel out its own expansion. His sea watch lost about…
- Portable, precise time then created a new problem on land.
Portable, precise time then created a new problem on land. Every town still set its clocks by its own noon, so a railway timetable had to reconcile hundreds of slightly different…
- Railway companies imposed standard time before any government did.
Railway companies imposed standard time before any government did. In 1883 North American railroads simply declared time zones into existence, and cities went along because the…
- In 1967 the second stopped being a fraction of a day.
In 1967 the second stopped being a fraction of a day. It was redefined as 9,192,631,770 oscillations of a caesium atom, cutting official time loose from the turning of the Earth.
- Satellite navigation is the same problem solved the same way.
Satellite navigation is the same problem solved the same way. GPS clocks tick about 38 microseconds a day out of step with the ground, and left uncorrected that drift would put…