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PRESENTATION ON ANCIENT SCIENCE.

NITU BTECH MBA IT B , 50.ANCIENT NAVIGATION TECHNIQUES USED BY ANCIENT NAVIGATORSINTRODUCTIONIn ancient days the people were unaware of techniques which are used now a days for navigation purposes. They didnt know about the magnetic compasses or an accurate watch to find the direction in which they were sailing their ships at that time. So they used the ancient navigation techniques for sailing their ships.ANCIENT TECHNIQUES USED BY THEM:POSITION OF STARS.SUN LOCATIONS.MOVEMENT OF WAVESTHE SOUTHERN CROSS IN THE NIGHT SKYSEA BIRDSSEA ANIMALS

THE NAVIGATORS USING STARS.The navigators used the star compass . The star compass is the basic mental construct for navigation. We have names for the houses of the stars -- the place where they come out of the ocean and go back into the ocean. If you can identify the stars, and if you have memorized where they come up and go down, you can find your direction. The star path also reads the flight path of birds and the direction of waves. It does everything. It is a mental construct to help you memorize what you need to know to navigate.

You cannot look up at the stars and tell where you are. You only know where you are by memorizing where you sailed from. That means constant observation. You have to constantly remember your speed, your direction and time. You don't have a speedometer. You don't have a compass. You don't have a watch. It all has to be done in your head. It is easy -- in principle -- but it's hard to do. The memorization process is very difficult.

THE NAVIGATORS USING THE SUN LOCATIONS.They used sun when it is low down the horizon. Ancient navigator has the names for how wide the sun appears and for the different colors of the sun path on the water .When the sun is low , the path is tight and when the sun is high , it gets wider and wider . THE NAVIGATOR USING THE WAVESSunrise is the most important part of the day. At sunrise they start to look at the shape of the ocean -- the character of the sea and by that they memorize where the wind is coming from. The wind generates the waves. They analyze the character of the waves. When the sun gets too high, they steer by the waves. And then at sunset repeat the pattern. The sun goes down , they look at the shape of the waves.THE SOUTHERN CROSSThe Southern Cross is really important to them. It looks like a kite. These two stars in the Southern Cross always point south ( Gacrux on top and Acrux on the bottom ). If they were travelling in a canoe and going south, these southern stars are going to appear to be rising higher and higher in the sky. If they went down to the South Pole, these stars are going to be way overhead.

SEA BIRDSThe main guides are sea birds. These are birds that sleep on their island homes at night. At dawn they go out to sea, and come back at evening to sleep. They go about 130 miles out in the morning and come back at night. This bird, when it is fishing, its wings flutter but when the sun goes down, it will rise up from the water so it can see, and it will go straight back to land. When we see these birds in the day, we keep track of them and wait for the sun to get low, and we watch the bird. The flight path of the bird is the bearing of the island. Then we turn on that bearing, sail as fast as we can, and at sunset we climb the mast to see if we can find the island.AN EXCEPTIONWhen it gets cloudy and can't use the sun or the stars, all they can do is to rely on the ocean waves. That's why it is said, "If you can read the ocean you will never be lost." One of the problems is that when the sky gets black at night under heavy clouds, they were not able see the waves. They cannot even see the bow of the canoe. And that is where people are so skilled. He can be inside the hull of the canoe and just feel the different wave patterns as they come to the canoe, and he can tell the canoe's direction lying down inside the hull of the canoeSOME OTHER IMPORTANT ASPECTSBefore the invention of the compass, watch, and the sextant, the mariner's main guide was latitude. To obtain their latitude, Arabs measured the altitude above the horizon to a known star, and then deduced from this the altitude of the Pole Star, (since the Pole Star was the one star that did not move in the sky). In some cases ancient navigators measured directly the altitude of the Pole Star. This was the simplest method, and was known as the science of qiyas.SOME OF ANCIENT SHIPS

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