,新课标人教版课件系列,高中英语 选修(模块）9-2.1,In pairs discuss these questions: 1 What is a navigator? A navigator explores new routes across the sea. 2 What is the difference between a navigator and an explorer? A navigator explores the sea; an explorer discovers new places on land.,Warming Up,3 Look at these famous people. Are they navigators or explorers? What do you know about them? Navigator sea nautical instruments find new islands or continents Navigator is someone who finds the position and plots the course of a ship, an aircraft, a car, etc, using maps and instruments.,Explorer land use of compass and landmarks find new places within an already identified island or continent Explorer is someone who travels into or through a place in order to learn about it. Very often navigators are also explorers.,Look at the pictures. Then answer the questions. 1 How do you think seamen found their way before modern accurate methods of navigation were invented? Kept close to the shore, used nature such as the sun, wind, birds, tide, etc, to help them, and used some of the instruments including a compass, astrolabe, etc.,Pre-reading,2 Which do you think was easier to work out: latitude or longitude? Latitude, because it was used to measure how far you had travelled from land on a straight line. It was discovered a long time before longitude.,3 Can you identify these early navigational instruments seamen used and explain how they are used? 1 _ 2 _ 3 _ 4 _ 4 Which ones do you think are still used today? Sea charts are still used today.,compass (in ancient China),astrolabe,sextant,sea / nautical / marine chart,Read the passage and answer the following questions. 1 What is the use of a bearing circle, astrolabe, quadrant or sextant? ( ) What is the use of a compass? ( ) A to set the course of the ship B to measure the position of the ship C to measure the speed of the ship D to tell the time,Comprehending,1,B,A,2 Why are speed and time important in working out the longitude of a ship? Speed and time are important in finding out the longitude of a ship because the earth moves fifteen degrees westwards every hour. If you know your direction, speed and time, you can work out the approximate longitude or change in your position in relation to the stars.,3 Why is the position of the sun and various stars useful for working out latitude? The position of the sun and stars are useful for working out latitude because they are fixed points in the sky and their movements in relation to the earth are already known. So they can be used to measure a ships position.,Suppose you were a sea captain aiming to sail round Africa. Discuss in groups: 1 What skills would you seek in your sailors? The sailors would need to be excellent navigators, able to cope with both hot and cold weather, experienced in sailing through very bad weather and able to co-operate in a team.,2,2 What problems would you anticipate for this journey? I would anticipate very hot weather (around the equator), cold weather (around the Cape of Good Hope), very stormy seas (around the Cape), and problems with food and water (unless helped by local natives the water may be contaminated and the food scarce), etc.,What would you do if you came across the following problems during your voyage? Read the chart below and fill in your plans of action to deal with them.,3,wait till the storm is over, and then find your new position and return to your original course,use knots to find your speed and work out your approximate longitude,use the compass and the astrolabe, quadrant or sextant to find out your position, return to your former course,follow nesting birds to shore; look for special cloud formations or fog over streams to find land,use a compass,measure your position using the sun or stars; look for sea birds, cloud formations, fog or seaweed to show that land is nearby,Read the passage again and use the information to analyse the navigational skills. Write the answers in your own words. Using nature 1 To find the ships position at sea a sailor used the North Star and the sun.,4,2 A sailor knew that land was nearby if he saw _ _ . 3 Sailors used _ to increase their speed.,fresh seaweed, nesting birds returning,home in the evening or fog,sea currents or tides and winds,Using instruments 4 There were two methods to find longitude: 1 _ 2 _ _ .,measuring time and speed,compass and complicated mathematical tables,5 Write down the working principles of the following instruments: Beating circle: _ . Astrolabe: _ .,to compare the height of the sun now with the position of the sun at midday,to compare the p