Everything Everywhere Daily: History, Science, Geography & More Longitude (Encore)
Oct 4, 2021
Navigating the open ocean has always been a formidable challenge. For centuries, mariners struggled with the mystery of determining longitude, leading to shipwrecks and disasters. The journey takes us through the impressive skills of Polynesian navigators and their unique techniques for crossing vast oceans. We also explore the limitations of early astronomical methods before uncovering the groundbreaking invention of the marine chronometer by John Harrison, revolutionizing navigation and paving the way for modern technologies like GPS.
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Longitude Challenge in Navigation
- Latitude can be determined easily with the pole star and a sextant. Longitude remained unsolvable for centuries, making precise navigation difficult.
- Accurate maps don't help if sailors don't know their precise longitudinal location.
Sable Island Shipwrecks
- Sable Island, a large sandbar near Nova Scotia, caused at least 350 shipwrecks. Many underwater hazards worldwide made navigation extremely perilous for European ships.
Latitude vs Longitude Measurement
- Latitude is measured by the angle of the pole star with the horizon using a sextant. Longitude was tricky because vertical lines rotate, making celestial fixes nearly impossible at sea.