- slide 1 of 2
History of Celesital Navigation
Since the first humans wanted to travel, they had a need to know where they were going. By trial and error, they discovered that the sun could show them where North, South, East and West were located as they walked through strange places or tried to return from hunting far from home. They probably used the moon for their directions, too, but undoubtedly discovered that it was unreliable. It’s rising and setting being hidden behind clouds from time to time.
After more years of traveling mostly by day or following established trails, the first humans who ventured away from their familiar surroundings must have had either a need or a desire to journey during the darkness. They started noticing the night sky and watched the stars as they wheeled through the heavens. Polaris, the current North Star, didn’t seem to move as much as the others and eventually became the beacon for night travelers. So the first stages of celestial navigation began.
Time passed and people began using ships to go from shore to shore, always having to keep within sight of land, for it was easy to lose bearings in the vast expanses of water.
From China came the compass, enabling the travelers to be sure of their direction regardless of whether or not they could actually see the sky. Marco Polo was the first European to visit China and brought back the knowledge of compasses for navigators of both land and sea, enabling them to journey further and further from home with a good chance of a safe return. Christopher Columbus used a compass in his voyage to the New World, aiming his ships toward the west.
Chronometers (clocks) were a vital part of navigation during the seafaring days as well. John Harrison invented the first chronometer in 1762 and won a contest with it! Little did he guess where his prize winning invention would take civilization in later years. The early chronometers had to be wound every few hours to stay accurate. Its use in navigation was to determine location by how far the “stars moved" in a specific period of time. Combined with a compass, sextant and/or astrolabe, the chronometer allowed sailors of old to travel all the oceans of the world enabling trade and advancing civilization.
For centuries, the technology didn’t progress very much. Chronometers eventually were improved to require less winding, and ultimately with batteries, no winding at all. In 1895 another breakthrough invention came about. Guglielmo Marconi came up with the first wireless communication device, the radio. In 1899 he sent the first successful radio signal across the English Channel via transmission towers. It was the first new step in navigation in many years, but nobody would realize it for several more years. Radio towers began to sprout up all over the world, making communication quicker and easier. Pilots of the early airplanes would use radio signals to tell where they were, in a general way. They would be able to hear transmissions from a particular place and know they were within a certain number of miles of it. For example, the broadcasting range of a radio station in Dallas Texas might have been 100 miles. If a pilot could hear the station, he knew he was within 100 miles of Dallas.
As often happens, wartime is a time of inventions and innovations. World War Two was no exception. Compasses, clocks, radios and celestial navigation all played their part in the War. Pilots were able to conduct both bombing raids and rescue missions with an accuracy that was remarkable for the time.
- slide 2 of 2
How GPS has Helped Navigation
Now it is the Twenty-first Century and we have a little treasure called GPS (Global Positioning Satellites), which combine all the same technologies that were used during World War Two. Those technologies have advanced considerably since then, of course. The military conducted the first experiments in satellite technology and came up with the first GPS system. Satellites are in orbit around the Earth, capable of receiving information and transmitting data back. The modern GPS can pinpoint a mouse hiding under a parked car in a huge parking lot! Well, it can pinpoint the car, anyway!
Many new cars come with a GPS system built in so the vehicle can never be lost and stealing it is a bad mistake. Vehicles with a GPS system can still be stolen, but they can be found in a matter of minutes.
Ships at sea no longer have to wonder where they are, their GPS system will tell them to the inch what their location is. This has been invaluable in finding missing ships, airplanes, and even verifying the location of old shipwrecks. If something is located underwater, out to sea, the GPS can verify exactly where the surface ship is and know that what they seek is directly beneath it.
Many people have personal GPS devices. Cell phones have them. Small units such as Tom-Tom or Garmin are handy for drivers who don’t like getting lost.
With all the new technology, why should anyone need to know anything about celestial navigation? It isn’t something that we really need in the course of our daily lives, after all. Or is it? What if you find yourself lost without any of the GPS goodies? If you don’t have a cell phone and your car breaks down far from civilization, a little knowledge of celestial navigation can save your life! People get lost in the woods every year, and those who know how to find their directions tend to have a better chance of survival.
Something to think about…