Chapter 4 The map is difficult to find the way

In the daily life of human beings, maps are an indispensable thing.For those years without maps, modern people who are used to looking at maps can hardly imagine.However, just as modern people do not understand that measuring the universe depends on mathematical formulas, the ancients did not know that travel depends on maps. The ancient Babylonians were proficient in geometry. They once conducted a survey of the cadastre of the entire Babylonian kingdom (the surveying time was about 3800 BC, 2400 years before the birth of Moses).There are pictures drawn on the pottery tablets found in those areas, and this picture is the general outline of the territory of Babylon at that time.But they are not yet "maps" in the modern sense.In order to extract every penny of taxes from their hardworking subjects, the rulers of ancient Egypt also measured the land of all Egypt.Later generations discovered that the reason why the ancient Egyptians were able to complete this arduous work was because they had mastered a wealth of applied mathematics knowledge at that time.But in the tombs of the ancient Egyptian pharaohs, no "map" in the modern sense has been found so far.

The thirst for knowledge of the ancient Greeks was the strongest. They wrote countless treatises on geographical issues, but they knew nothing about their map descendants.In some well-developed ancient Greek commercial cities, bronze plates engraved with the best sailing routes seem to have appeared, telling merchants how to get to the islands in the Eastern Mediterranean.But these bronze plates are still a mystery to modern people. They are still buried in the ground, and it is unknown when they will see the sun again.Alexander the Great conquered such a vast area. He was an emperor who has never been seen before or since. In his Macedonian legion that was tireless in search of gold, there was a special team that led the way. They marched at the forefront of the legion , able to report exactly how far their regiments were from India's gold.It can be seen that Alexander the Great must have some kind of "geographical awareness".However, the map we can understand still cannot be found from a relic, a fragment or a route.

The ancient Romans were predatory (they were a gang of "regular bandits", the most well-organized, and their crimes began to be recorded in the era of their colonial rule in Europe), and they lived wherever they went. Wherever it was repaired, taxes were collected; where they passed, they either hanged the conquered with ropes or crucified the conquered; wherever they went, they built temples and swimming pools, Then leave ruins one after another, and let future generations pay their respects.Though it is true that Roman writers and orators often spoke of Roman maps, and boasted how accurate and reliable their maps were.And they don't seem to need a map worthy of the name, these Roman bandits managed to subdue and rule a world-class empire.But the only Roman map we have (except for the worthless small Roman plan from the 2nd century AD) is so crude and crude that it has no real value except as an antique collection.

Historians know of an ancient Pottinger map named after Conrad Pottinger.Konrad Pottinger, deacon of the city of Augsburg, was the first to attempt to mass-print ancient Roman maps with the help of a printing press invented by Johann Gutenberg of Strasbourg.Unfortunately, Pottinger has no originals available for reproduction.The manuscript he used was a 13th-century copy of a 3rd-century map, but the copy was incomplete because rats and moths destroyed many important parts of the 1,000-year-old map. details. Even so, the Pottinger map is undoubtedly the same in general outline as the original.If the 3rd century original is the finale of the ancient Romans, then their geographical knowledge has yet to be further enriched and perfected.I copied this ancient Roman map, judge for yourself.After studying this ancient map carefully, you will understand what the level of Roman geographers was.When the Roman generals wanted to go to England or march to the Black Sea, the best evidence they could find was this spaghetti-like map.How far humanity has come since then to the Legion!

Medieval maps, on the other hand, are simply dismissive.The church abhors all "useless scientific exploration".Knowing the way to heaven is more important than knowing the shortest route from the mouth of the Rhine to the mouth of the Danube.As a result, the map was drawn into funny pictures, sirens, mermaids, headless devils (this unique image originated from those poor Eskimos who often tucked their heads in fur coats), snorting unicorns, snorting unicorns, etc. The water whale, the winged half eagle, half horse monster, the winged half eagle and half lion monster, and all the monsters representing the embodiment of fear and superstition appeared on the map.Therefore, the center of the world is naturally Jerusalem, India and Spain are drawn to the edge of the world, Scotland is a lonely island, and the Tower of Babel (Tower of Babel) is 9 times larger than the entire city of Paris.

And the woven maps of the Polynesians (which look like the kindergartners' knick-knacks, but are, in fact, practical and accurate) are indeed navigators compared with the works of medieval cartographers. masterpiece of genius.Although Arabs and Chinese have always been regarded as shameful "heretics" and excluded from the world centered on Europe, let alone their geographical achievements at that time.In this way, until the navigation industry finally developed into a science, at the end of the 15th century, map drawing made substantial progress. At that time, the Turks conquered the bridgehead connecting Europe and Asia, and cut off the land traffic from Europe to the East for a long time. Therefore, the first task at that time was to find a passage to India in the sea.The great advances in seafaring at the time were driven by the urgent need to open up sea lanes.People are gradually getting used to the long sea voyage where there is nothing but the blue sea and blue sky, and bid farewell to the traditional navigation method of relying on finding church spiers on land or distinguishing the barking of dogs along the coast.

The furthest the ancient Egyptians seem to have been is the Greek island of Crete, and their visit looked more like a chance encounter after being blown off course than a well-planned sailing expedition.Although the Phoenicians and Greeks have done several earth-shattering events, they even sailed to the Congo River and the Scilly Islands (the Scilly Islands cover an area of ​​21.5 square kilometers and are located 58 kilometers west of the Cornwall Peninsula in southwest England. It is composed of more than 50 small islands——Translator's Note) there, but these sailors would rather sail for a lifetime next to the church.Even on the way to the Congo River and the Isles of Scilly, they saw Lu Bideng. In order to prevent their boat from being blown by the wind into the middle of the sea where the land could not be seen, they must tow the boat to the land on the shore at night.Although medieval merchants sailed across the Mediterranean, North Sea, and Baltic, they never let the mountains ashore disappear from their view for more than a few days.

If these traders lost their way in the sea, they asked the pigeons to help them find the nearest land.They always sailed with pigeons, and the pigeons were able to fly the shortest route to land.When they couldn't tell the direction, they released a dove and followed the dove's direction until they saw the mountains on land.They moored at the nearest port, and went to find out where they were. In the Middle Ages, even an ordinary person knew more about the distribution of stars in the sky than modern people.That era could not provide the printed almanacs and calendars that modern people have, so they had to have the knowledge.At that time, captains with a little knowledge could identify their directions by observing the stars, and they could also plan their routes based on the directions of Polaris and other constellations.But in the north, the weather is often cloudy, and the method of looking at the stars sometimes does not work.If that foreign invention had not been introduced to Europe by the second half of the thirteenth century, European navigation would have continued its costly and painful journey, relying entirely on luck and guesswork (the latter being more than half).The origin and development of the compass is still a mystery.What I said here is just a speculation (one of the four great inventions in ancient China. Due to the influence of the traditional prejudice of the West against the East, the author had a wrong understanding——Translator’s Note).

In the first half of the 13th century, an unprecedentedly vast empire emerged in Eurasia (from the Yellow Sea in the east to the Baltic Sea in the west, and ruled Russia until 1480). A Mongolian with short stature and squinting eyes——Genghis Khan He is the ruler of this empire.He must have had something like a compass in his hand as he traveled across the vast deserts of central Asia to enjoy the pleasures of Europe.When did Mediterranean sailors first see a compass?It is difficult for us to explain clearly today, but we can be sure that the Mediterranean fleet will soon visit the ends of the world under the leadership of this invention called "the invention of the devil and Satan blaspheming God" by the church.

In general, the origin of such major inventions of world significance is somewhat vague.People who went to Jaffa or Famagusta in Pakistan at that time probably brought a compass with them when they returned to Europe.He had bought it from a Persian merchant, and the Persian merchant had bought it from a man who had just returned from India.In the beer halls of the port, the news spread quickly, and people wanted to see this wonderful little needle that Satan had bewitched.It is said that no matter where you go, this little needle can always tell you which direction is north.Of course, people couldn't believe it was real.However, no matter what, many people still ask their friends to bring back a compass when they go to the East next time, and they also pay the deposit in advance. Therefore, after half a year, these people also have a compass themselves.The magic power of Satan is really powerful! From then on, everyone wanted to have a compass, and they eagerly hoped that the merchants of Damascus and Smyrna (now the port of Izmir on the western coast of Turkey--Translator's Note) would buy it from the East. Back for more compass.As a result, instrument manufacturers in Venice and Genoa also considered making this thing.A few years later, this small metal box with a glass lid became popular, and it became a common thing, but no one thought that its existence was worth writing about.

As for the origin of the compass, let’s stop here, or let it return to its mysterious world! Since the first batch of Venetians sailed from their shallow strait to the Nile Delta under the leadership of this sensitive needle, Human beings' understanding of the compass has improved a lot.For example, it was found that it does not always point to true north, sometimes a little bit easterly, sometimes a little bit westward—in technical terms, this difference is referred to as "magnetic variation".Magnetic variations occur because the north and south magnetic poles are not at the same point as the earth's north and south poles, but hundreds of miles apart.The South Magnetic Pole is at the intersection of 73° south latitude and 156° east longitude.The North Magnetic Pole is on Busia Island in northern Canada (Sir James Ross first landed on this island in 1831) (James Ross, a British naval officer, 1800-1862, has made magnetic measurements in the North Pole and Antarctica—— —Translator's Note). Due to the existence of magnetic variations, it is not enough for a captain to have a compass, but also to have a nautical map in order to understand the different magnetic variations around the world.This involves navigation, and navigation is a very complicated and profound knowledge, which cannot be explained clearly in a few words.This work is not a navigation manual, I just want you to know that the compass was introduced to Europe in the 13th and 14th centuries, and navigation was no longer dependent on lucky guesses and painful and complicated calculations, but became a A proven science. And that's just the beginning. Modern people can know their own heading very clearly, either to the north, or north by east, or north-north by east, or north-east by north... or the 32 directions indicated on the compass any of the .When a medieval captain navigated the vast sea, he had only two tools to rely on. One is a sounding rope.The sounding rope came out almost together with the sailing ship.It can measure the depth of any point in the ocean.If the captain had a chart of their current voyage, showing the various depths of the ocean, the sounding rope would tell him what the waters were like, and thus determine the direction of the ship. The other thing is the speedometer.The most primitive speed measuring device is a piece of wood, throw it into the water from the bow, and then carefully observe how long it takes for the stern to pass through this piece of wood. The length of the fixed point can be used to calculate the speed of the ship. Later, the rope replaced the wood chips.This kind of rope is very long, thin and strong. It is pre-knotted one by one according to a fixed length, and a triangular piece of wood is tied to one end of it.When the rope is thrown into the water, the hourglass is turned on.After the sand has drained from the bottle (of course, the length of the hourglass is known in advance, usually two or three minutes), the rope is pulled up from the water, and the number of times the sand leaks from one bottle to the other is counted. How many knots are there for launching into the water?A knot represents one nautical mile, so it is possible to know how many nautical miles the ship has traveled during this period, so as to calculate the speed of the ship. However, it is not enough for the captain to know the speed and course, because his most precise calculations may be disturbed by currents, tides and winds at any time.So, even long after the introduction of the compass, any ordinary sea voyage was probably a most adventurous experience.Those who wished to solve the problem theoretically realized that, in order to change the situation, a new object must be found for the ship at sea to replace the steeple of the church. This is definitely not a joke.Church spires, tree canopies on beach dunes, windmills on dikes, and dogs barking along the coast—these objects have all played important roles in the history of navigation because they were fixed Whatever happens, they're always there.With these reference objects, sailors can calculate their position.Because he remembered passing by here last time, and then told himself: "I must continue to sail east." , but can achieve the same outstanding achievements as the predecessors in the field of mathematics) The key to this problem is very clear, that is, to find an essential "reference object" to replace those artificial "reference objects". This work has been underway since 200 years before Columbus crossed the Atlantic, and it remains unfinished today.Wireless timekeeping systems, underwater communication systems and mechanical steering devices have been used in today's navigation, and the old helmsmen have almost been swept into the garbage dump of history by these masterpieces of the industrial age. Suppose you are under a tower, and this tower is built on the surface of a huge sphere, and a flag is flying on the top of the tower, as long as you stand there still, you will find that the flag is in the The top of your head is right above.If you walk away from the tower, the flag will form a different angle in your field of vision, as shown in the picture, this angle is determined by the distance between you and the tower. Once this "fixed point" is found as a reference, the problem is simplified a lot at once.It's just a matter of calculating angles, and people have been familiar with it since ancient Greece.The ancient Greeks were very proficient in the relationship between the sides and angles of a triangle, which laid a solid foundation for the development of trigonometry. The problem of angles brings us to the most difficult part of this chapter, to be precise, the most esoteric section of the work—the problem of determining latitude and longitude.Latitude was determined hundreds of years before longitude was determined.On the surface, it seems that determining the longitude is easier than determining the latitude, but the ancients did not have timekeeping instruments, so it is indeed difficult to determine the longitude.As for latitude, it can be determined only by careful observation and careful calculation. Therefore, human beings have solved this problem earlier.The above is just a basic overview, and the following will explain the problem of latitude and longitude as concisely as possible. In this picture, what you see are several planes and angles.Standing at point D, you will find yourself directly below the tower, just as you would be standing directly below the sun at 12 noon on the equator line.When you get to point E, the situation is bound to change.Since you are stepping on a sphere, you need to draw a plane when calculating the angle.Draw a straight line from the imaginary center point A of the earth, pass through your body, and reach the zenith (in astronomy, a point in the sky directly above the observer is called the zenith, and its official name is zenith; the observer is The point in the sky below is called nadir). Experiments are needed to illustrate this complex issue.Put a sweater needle through the center of the apple, assuming you are standing on one side of the apple, the sweater needle is behind your back.The upper end of the sweater needle is the zenith, and the lower end is the nadir.Then, assume that a plane is at right angles to your position and the direction of the sweater needle. If you are at point E, this plane is FGKH, and line BC is a straight line on this plane you observe.To keep things simple, let's also assume that your eyes are on your toes, which is exactly at the point on the line BC where your feet are stepping on.Then look up at the flagpole on the top of the tower, and calculate the angle between the top of the flagpole (L), your bearing (E), and the intersection of the line BC and the plane FGKH (the plane is at right angles to the line from the zenith to the center of the earth ), if you know trigonometry, you can calculate the distance between you and the tower through this angle.If you go to point W, then calculate according to this method. W is your bearing on the straight line MN, which lies on the plane OPRQ and is at right angles to the line from the center of the earth to the current zenith (the zenith naturally moves with the observer).As long as you calculate the angle of the LWM angle, you will know how far you are from the tower. Even if explained in the simplest way, the problem still looks very complicated.Therefore, here is just an overview of the basic theories of modern navigation.If you want to be a sailor, you have to go to a professional school, spend a few years learning how to do these necessary calculations, and then, after another twenty or thirty years, when you have mastered all the tools and tables and tables. Nautical chart, after being able to control the crew across the world, you may be hired by the ship owner as the captain.Of course, if you don't have such ambitions, you don't need to learn these complex and tedious arithmetic, so don't mind the brevity of this chapter, I just talked about some overviews. Because navigation is almost entirely a computational science, it was not until the Europeans rediscovered trigonometry that there was a great breakthrough in the theory of navigation.Although the ancient Greeks had laid a solid foundation for this science, after the death of Ptolemy (the famous geographer of Alexandria in ancient Egypt), trigonometry was regarded as a sophisticated, complicated and extravagant science. Learning, the science that is not easy to master, is thrown aside and gradually forgotten.However, the Indians and later the Arabs in North Africa and Spain did not have such concerns. This unwanted ancient Greek heritage was preserved by them and continued to be carried forward. The Arabic terms "zenith" and "nadir" amply illustrate that trigonometry was no longer a Christian heritage when European schools again included it in their curriculums (around the thirteenth century), And it became the treasure of the Islamic people.But in the following 300 years, the Europeans rushed to catch up, catch up and overtake, and came from behind.Although they once again understood how to calculate angles and how to solve triangle problems, they found themselves facing another problem—how to find a fixed point far away from the earth, which could replace the church spire as a reference. This lofty honor is worn on the head of Polaris, and Polaris has become the most reliable navigation reference.Because the Polaris is so far away from man, it appears to be stationary; besides, it is so easy to spot that even the dumbest lobsterman can find it if he loses his bearings.As long as you look along the straight line of the two rightmost stars of the Big Dipper, Polaris will come into people's field of vision.Of course, the sun is also a constant reference object, but science has not yet calculated the orbit of the sun, so only the most knowledgeable navigators have the ability to turn to the sun. In the era when people were forced to accept the theory that "the earth is flat", it was inevitable that all arithmetic would deviate from the objective reality.By the beginning of the 16th century, this embarrassing situation finally came to an end, and the sphere theory replaced the disk theory.Geographers are finally able to preside over the truth and let geography show itself. First of all, geographers use a plane (this plane is perpendicular to the central axis connecting the north and south poles) to divide the earth into two parts, north and south. The dividing line is called the equator, and the distance from the equator to the north and south poles is the same.Then, they divided the distance between the equator and the two poles into 90 equal parts. In this way, 90 parallel lines (because the earth is round, so each parallel line is a circle) are evenly distributed between the equator and the two poles. The distance between each line is one-ninth of the distance from the pole to the equator, and is 69 miles long. These circles were then numbered by geographers, from the equator to the poles, with 0° at the equator and 90° at the poles.This is the latitude (as shown in the picture). Therefore, the establishment of latitude is a sign of great progress in geography.However, even so, sailing is still very dangerous.Before all captains knew how to calculate latitude, generations of mathematicians and navigators worked hard to collect data related to the movement of the sun, and to record the exact position of the sun at each location every year, every month, and every day. In the end, any smarter navigator, as long as he can read and write, can judge his position in a very short time at a few degrees of north latitude (the latitude north of the equator is called north latitude, and the south of the equator is called south latitude) or south latitude. A few degrees, in short, is how far he is from the poles and the equator.In the past, it was not easy for ships to cross the equator to sail in the southern hemisphere, because the North Star was invisible in the southern hemisphere, so the ship lost the reference for navigation.This question was finally solved by science.By the end of the 16th century, navigators no longer had to worry about latitude. However, the question of longitude remains unresolved (you should know that lines of longitude are perpendicular to lines of latitude).It took more than two centuries for humans to successfully solve this mystery.When determining latitude, scientists use two fixed points, the South Pole and the North Pole, as a benchmark.They said: "They are fixed forever, the 'church steeples' of man." However, the earth has neither an east pole nor a west pole, nor does the earth's axis lie in that direction.Of course, one can draw an infinite number of meridians, that is, the circle that passes through the two poles and encircles the whole earth in a north-south direction.But which meridian should be designated as the "prime meridian" as the dividing line between the eastern and western hemispheres? Because of this line, sailors can say: "I am now 100 miles east (or west) of the prime meridian." Miles.” Since Jerusalem was deeply rooted as the center of the world in the traditional concept of many people, they demanded that the longitude passing through Jerusalem be designated as the prime meridian to divide the eastern and western hemispheres, that is, the vertical “equator”.However, this plan went bankrupt because of national self-esteem, because all countries wanted to take the Prime Meridian as their own and let the world start from their own capitals.Even now, human beings think that their minds have been broadened a lot, but the prime meridian is set at Berlin, Paris and Washington, and it still appears on some maps of Germany, France and the United States respectively.As a result, the meridian that passes through Greenwich was chosen as the prime meridian, the dividing line between the eastern and western hemispheres, because England made outstanding contributions to the development of navigation in the 17th century (the year when longitude was determined). contribution, and because the nautical industry at that time was under the supervision of the Royal Observatory established in Greenwich, near London, in 1675. In this way, the voyagers have a "church spire" in longitude, but they still face a problem: in the vast sea, how will they determine the distance between themselves and the Greenwich meridian? In order to finally solve On this issue, in 1713, the British government established the "Maritime Longitude Determination Committee".In order to reward the best inventions that enable human beings to determine the longitude on the vast sea, this special committee set up a huge prize. $100,000 was indeed a huge sum of money more than two centuries ago, and many people worked hard for it.When the committee disbanded in the first half of the 19th century, it had handed out more than half a million dollars in prize money for inventions that qualified as "inventions." History has now forgotten most of the efforts of these men, and time has gradually obsoleted their inventions.But to this day, two inventions born under heavy prizes still have their practical value.These two inventions were the sextant and the astronomical clock. A sextant is a complex instrument (a small marine observer that can be clipped under the arm and carried around) with which distances at various angles can be measured.The crude medieval observatory, rectangular instrument and 16th-century quadrant (quadrant) are the direct sources of this invention.As so often happens when the whole world is pursuing the same question at the same time, three men each claimed to be the original inventor of the sextant, and fought hard for the honor. The nautical community expressed excitement about the advent of the sextant, but this excitement seemed tame compared to their interest in the astronomical clock.The astronomical clock is a precise and reliable timekeeping device; it was born in 1735, four years after the sextant.The inventor of the astronomical clock, John Harrison, was a genius at making clocks (he also worked as a carpenter before becoming a clockmaker).This astronomical clock is so accurate that it can tell Greenwich Mean Time in any form anywhere in the world, and it is not disturbed by changes in the weather.This is because in the astronomical clock, Harrison added a device called "compensation arc", which can adjust the length of the balance spring to adapt to the thermal expansion and contraction caused by the temperature difference. Changes have no effect on the chronometer. After a long and unseemly haggling, Harrison was finally paid $100,000 three years before his death (1773).Today, as long as a sea-going ship carries an astronomical clock with it, no matter where it sails, it can know Greenwich Mean Time accurately.Since the sun revolves around the earth every 24 hours (its revolution direction is exactly opposite to the earth's rotation direction, but from a convenient point of view, I use the same expression), and every hour passes through the 15° meridian, so, as long as you know The local time of the ship and the Greenwich Mean Time, the distance between the ship and the prime meridian can be calculated by the difference between the two times. For example: if the local time where the ship is located is 12:00, Greenwich Mean Time is 2:00 pm at this time, and the sun passes through the 15° meridian every hour, then the distance between the ship and Greenwich is 2×15° =30°.Therefore, it can be recorded in the logbook: at noon on a certain day of a certain year, the ship arrived at 30° west longitude. The invention of the astronomical clock in 1735 was shocking, but today the astronomical clock has gradually lost its original importance.Now, with the Greenwich Observatory telling the hour around the world every day at noon, the astronomical clock quickly became a luxury.In fact, if we do not doubt the ability of the navigator, all the complicated tables and labor-intensive calculations can be thrown into the sea by wireless communication.In this way, mankind will turn over the most glorious period of nautical history, and bid farewell to all the nautical legends about courage, patience and wisdom.Gone are the unexplored seas, the days when even the best sailors would be overwhelmed and lost for a moment before a stormy sea.The imposing man with the sextant will sit no longer in the wheelhouse but in the cabin, with headphones on, asking, "Hello, Nantucket (or, "Hello, Cherbourg"), can I What is your current position?" The navigator on land will report his current position.It's that simple. In order to be able to traverse the surface of the earth safely, happily and productively, human beings have made efforts for more than twenty centuries, and these twenty-odd centuries have not been wasted.This is the first successful international cooperation experience in human history.The Chinese, Arabs, Indians, Phoenicians, French, Dutch, Greeks, English, Spaniards, Portuguese, Norwegians, Swedes, Italians, Danes , Germans, have made their own contributions to the cause. A special page in the history of human cooperation is coming to an end.But there are many other things that keep us busy for a while.