How does GPS work?
Longitude + Latitude = Smart navigation
The first sea navigators simply followed recognizable landmarks. Which is fine, but was not without some fairly obvious drawbacks. For one, you have to travel by daylight and stay close to shore. Also, if you’re relying on recognizable landmarks, how would you ever discover anywhere new?
As demand increased to trade across the waters, so navigators learned to calculate their latitude (how far north/south you are on the globe) by reading the sun during the day and the North Star at night, allowing them to navigate out of sight of land.
In time, the success of local economies came to depend increasingly on the ability to trade efficiently farther and farther afield. Enterprising people responded to this economic need by developing newer and better navigational tools and techniques.
Every now and then, this gradual evolution of navigation would get an extra impulse. For example, when European countries discovered the riches to be made across the oceans in the Americas, Africa, and the Far East. One consequence of which was the founding about 400 years ago of the world’s first multinational: The Dutch East India Company.
By the 1700s it had become clear that whichever country could first find a way to accurately measure longitude at sea would have a massive trading advantage over its rivals. So the great maritime powers of the day - France, Holland, Britain, Spain, Portugal, and others - put their best brains on the case. Who won out, and why is an amazing story in itself.