Longitude is a geographical coordinate that specifies the east-west position of a point on the Earth’s surface. It is an angular measurement, usually expressed in degrees and denoted by the Greek letter lambda (λ). Longitude measures how far east or west of Greenwich England any place on earth lies. This was important for early sailors who needed to know their exact location while at sea so they could accurately chart their course and avoid getting lost.
In order to accurately measure longitude, scientists had to find ways to determine time with precision even when ships were out at sea without access clocks or other reliable sources for telling time. They eventually developed chronometers which used complex mechanical movements powered by springs that allowed them keep accurate track of hours and minutes no matter where they were located in relation to land masses like Europe or North America. This technology was essential for navigation as it enabled sailors determine exactly what degree longitude they were located within seconds rather than days if using traditional methods such as star gazing.
Today most modern navigational systems use GPS satellites which allow people pinpoint their exact locations anywhere around globe within seconds instead relying upon old school methods like chronometers measuring longitudes manually from stars night sky.