How did explorers use stars to navigate
Navigation then and now
Finding your way in a strange city is no longer a problem today. After all, many cars and almost every cell phone have a built-in navigation device. But what was it like in the past, when people didn't have any technical aids to get them to their destination?
Fixed points on land and in the sky
The word "navigare" comes from Latin and means "to steer a ship". Even the ancient Egyptians, Phoenicians and Sumerians set out to sea to trade with other peoples and to discover unknown areas. The ancient seafarers orientated themselves at prominent points on the coast and observed the wind and wind direction. Over time, they learned to orient themselves on the high seas using fixed points in the sky that can be seen from anywhere. They measured the depth of the water with a plumb bob. The art of navigation was mainly passed on orally to subsequent generations.
Observation of the sun, moon and stars
Already in antiquity there were sailing instructions, the so-called peripli, with information on distances, shoals and dangerous currents that showed the Greek seafarers the way. The first medieval portolans - the forerunners of today's nautical charts - emerged from these sea route descriptions from the 13th century. However, they were still quite imprecise. That only changed when navigation became a science based on astronomy, geography, and cartography.
Compass, Jacob's staff and sextant
Little by little, the seafarers developed better and better measuring instruments for orientation. Chinese navigators were the first to use magnetic needles to navigate. The magnetic needle initially floated in a bowl of water, later the needle was placed on a pin so that it could orient itself to the north in the earth's magnetic field. Later the magnetic needle came into the center of the compass rose so that a graduation was possible. With the compass one could determine the direction of travel of the ship or the position of a place in relation to the north cardinal direction. The Portuguese explorer Vasco da Gama, who was the first to find the sea route to India, already had a magnetic needle compass on board.
In addition, calculation methods were already known in antiquity with which the angular distance between the horizon and the sun or a solid celestial body such as the Pole Star could be calculated. The angular distance could be represented in a simple way with the Jacob's staff. It had been part of the standard equipment of seafarers since the 15th century and was a forerunner of the sextant, which worked on a similar principle. The angle between the fixed star and the horizon is measured with a sextant. In addition to the compass, the sextant was one of the most important instruments for determining the position of a ship. Even those who go to sea today must be able to use these aids in the event that the technology fails in order to find the right path.
Older people look at the menu, younger ones usually don't
Today's navigation devices are based on digital geographic information and position determination using GPS, the satellite-controlled global positioning system. While this technology primarily has a pilot function for the elderly and they often also take a look at the map to orientate themselves, young people in particular often rely completely on the technology.
Be careful when using the navigation device in the car
However, blind trust in technical navigation can have negative consequences. In some cases, the devices show roads that do not even exist or that have long been closed to car traffic. But it is not just blind trust that can lead to wrong turns and accidents. Anyone using the device while driving is distracted and therefore inattentive.
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My afternoon | 09/29/2017 | 4:20 pm
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