Great Inventions that Changed the World (Wei/Inventions that Changed the World) || Transportation

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<ul><li><p>CHA P T E R6TRANSPORTATION</p><p>For all the plants and animals, the ability to travel and migrate is fundamental in</p><p>nding food and water, seeking mates, dispersing from crowded family grounds,</p><p>escaping from predators and environmental threats, and colonizing better habitats.</p><p>Plants send out pollen, seed or fruit; the methods of dispersal can be passive</p><p>attachment to bees and butteries, to the feathers of birds and the fur of mammals,</p><p>or in their stomachs; others are borne by the wind and currents of water. Random</p><p>dispersal does not give control over the path or destiny, and a huge number of</p><p>travelers are required for a few to survive and succeed. Animals can actively travel</p><p>on their own, thus gaining greater control on the path and destination. Some animals</p><p>migrate between two habitats on a regular or annual basis, such as monarch butter-</p><p>ies, storks, and arctic terns that y round trip each year from the North Pole to the</p><p>South Pole. Some animals colonize new territories, such as Darwins nches from</p><p>South America to the islands of Galapagos.</p><p>In the primitive world of Gilgamesh from Uruk in Iraq, the people seldom</p><p>traveled very far and lived mainly on local resources. Gilgamesh took a memorable</p><p>journey with his companion Enkidu, and walked to the cedar forest of mountainous</p><p>Lebanon that is some 1200 km away. They killed the monster Humbaba to gain eter-</p><p>nal fame, but they also cut down cedar for lumber to build a temple in Mesopotamia,</p><p>which had no local stones or timber. Later, Gilgamesh traveled alone to visit his</p><p>ancestor Utnapishtim in a far away land that no one ever visited, to seek wisdom</p><p>about the origin of mankind and the knowledge of immortality.</p><p>An isolated people have limited resources and exposure to ideas, and can eat</p><p>only foods that are found or grown locally, use only local materials for tools, hear</p><p>and learn only local ideas, and mate only with locals and risk inbreeding. When</p><p>transportation was difcult, only the most valuable and imperishable goods were</p><p>transported over long distances, such as obsidian and int in the Neolithic Age,</p><p>copper and tin in the Bronze Age, and turquoise and lapis lazuli in historic times.</p><p>Rome had glass and China had silk, so trade along the Silk Route from the rst</p><p>century BCE made them both live better. Besides the better-known land route that</p><p>Marco Polo took to China, there was also a maritime Silk Route that sailed along</p><p>the southern coast of Asia from China to India, and then to the Persian Gulf or the</p><p>Red Sea, which Marco Polo took on the way home. Just as important as goods are</p><p>the spreading and sharing of ideas, inventions, and technologies. New ideas and</p><p>religions, such as Buddhism, Christianity, and Islam were carried and spread by</p><p>travelers. Great travelers in history gave us much of the knowledge of the world,</p><p>such as Marco Polo, Ibn Batuta, Christopher Columbus, Vasco da Gama, and</p><p>Great Inventions that Changed the World, First Edition. James Wei. 2012 John Wiley &amp; Sons, Inc. Published 2012 by John Wiley &amp; Sons, Inc.</p><p>197</p></li><li><p>Ferdinand Magellan. Western ideas such as democracy and capitalism have also</p><p>played principal roles in changing the world.</p><p>Transportation has a principal role in tying people from far-ung lands together</p><p>socially and politically. The Nile River played a critical role in unifying the Upper</p><p>Egypt of Luxor and Aswan together with the Lower Egypt of the delta. Roman roads</p><p>were responsible for the unity of the empire for a thousand years, by collecting taxes</p><p>and resources to Rome, and by sending legions to pacify and conquer frontier prov-</p><p>inces. The Portuguese, Spanish, Dutch, and British Empires were all created and</p><p>maintained by large ocean-going vessels. Travel also opened opportunities for new</p><p>habitats, conquests, and colonial empires. The ancestors of men came from East</p><p>Africa, and the Homo erectus ventured into Europe and Asia. The Polynesians</p><p>journeyed to populate the islands in the vast Pacic Ocean, and the Native Americans</p><p>walked 17,000 km from the Bering Strait in the north to Tierra del Fuego in the south.</p><p>Transportation also creates larger markets, making available a greater diver-</p><p>sity of goods and services for consumers; this larger market is also responsible for a</p><p>greater diversity of employments and specializations. In an isolated community, a</p><p>person has to be a jack of all trades, including growing food, making clothes, build-</p><p>ing a shelter, delivering babies, healing the sick, and educating children. A market</p><p>of larger size can afford a few specialists, such as a toolmaker or a healer, with</p><p>enough demand to justify an investment in special training and tools. A metropoli-</p><p>tan market can afford brain surgeons and fertility clinics with superior knowledge</p><p>and experience, as well as special tools. Inside a community, good transportation</p><p>makes possible the separation of workshops away from homesthe workshop can</p><p>be noisy and stressful, as well as dirty and dangerous, but the homes should be quiet</p><p>and clean. When a city has a good transportation system, it can create separate busi-</p><p>ness and industrial zones, away from restful residential areas.</p><p>A traveling vehicle needs to carry its own fuel and engine, where the measure</p><p>of efciency is the power/weight ratio of the engine-fuel system. A oating ocean</p><p>ship can afford to carry heavier engines and fuels; land vehicles such as automobiles,</p><p>trucks, and buses need engines with higher power/weight ratios; and airplanes need</p><p>the most power to stay in the air and require the highest power/weight ratios.</p><p>There is also a negative side to good transportation and globalization of the</p><p>world. The introduction of foreign species of plants and animals often lead to the</p><p>decline or obliteration of native species. In the human world, globalization often</p><p>means the decline or disappearance of regional differences in languages and cul-</p><p>tures, as well as that of indigenous ethnic groups that are unable to compete. The</p><p>Chinese philosopher, Laozi of 500 BCE, rejected commerce and technology. He</p><p>described his ideal as a small state in Book 80 of his canon, the Dao De Jing:</p><p>A small state with few inhabitants</p><p>No special employment for exceptional individuals</p><p>People do not ee to avoid danger and death</p><p>They do not use boats and carts, armors and weapons</p><p>They reject writing, and return to tying knots</p><p>They enjoy simple food, clothing, dwelling and ways</p><p>A neighboring village is within sight</p><p>They can hear cocks crow and dogs bark</p><p>People grow old and die, but do not visit each other</p><p>198 CHAPTER 6 TRANSPORTATION</p></li><li><p>6.1 LAND TRANSPORTATION</p><p>Walking and running are the oldest methods of transportation on land, with free</p><p>hands to carry infants and objects. Human power is low in speed and carrying</p><p>capacity, and animal power was added later with the domestication of oxen,</p><p>donkeys, camels, and horses. The backs of animals were used to carry people and</p><p>packed goods. Another method involved the invention of sleds and poles to drag</p><p>goods, especially over reasonably smooth surfaces, such as sand and ice. The ances-</p><p>tors of men were able to walk from Kenya to western Asia, and then disperse west</p><p>into Europe and east into East Asia. The most astonishing accomplishment was</p><p>that they walked from East Asia north to the Arctic, across the Bering Strait to</p><p>North America, and then continued to walk south to Patagonia at the tip of South</p><p>America. It would have been very difcult to carry anything beyond the essentials</p><p>on such journeys.</p><p>The wheel was a great invention, which permitted more rapid transportation</p><p>of heavier goods over longer distances. Bridges are needed to cross rivers and other</p><p>obstacles, and require long-term investments by more mature and organized socie-</p><p>ties. The rst great modern invention on transportation was thermal power to propel</p><p>steamships and steam locomotives. The coast-to-coast American railroad network</p><p>was critical to creating a unied nation and a society with shared values; the Siberian</p><p>railroad made possible the Russian Empire from St. Petersburg to Vladivostok</p><p>on the Pacic. The main shortcoming of steam locomotives is their dependence on</p><p>railroad tracks, which require expensive investments and inexible routes, so they</p><p>are only suitable for large volume travel between major nodes, such as New York to</p><p>Washington. The private automobile with the internal combustion engine requires a</p><p>distributed network of roads, with trunk lines for large volume interstate highways</p><p>and local roads that service low volume trafc between any two given points. Trans-</p><p>portation needs engines and fuels; control methods such as the whip, the steering</p><p>wheel, and the brake; and navigation methods such as the compass, maps, and the</p><p>modern GPS. The other major form of land transportation is a network of pipelines to</p><p>carry water, oil, gas, and sewage.</p><p>The performance of transportation is measured by the speed, the weight car-</p><p>ried, and the degree of security from natural storms and from human bandits and</p><p>war. The record for a human runner in the Marathon is 20 kph over 44 km. In com-</p><p>parison, the record for a horse at the Kentucky Derby is 63 kph; and the top speed of</p><p>a running cheetah is 120 kph. An automobile and a commuting train can easily do</p><p>100 kph for a very long time without becoming tired, but they are surpassed by the</p><p>top speed of the magnetic levitation train, which travels at 600 kph without the use</p><p>of wheels.</p><p>6.1.1 Wheel</p><p>It takes energy to move an object, which is the product of the force needed and the</p><p>distance traveled. It takes power to delivery energy quickly, which is the product of</p><p>the force needed and the velocity of travel. On the land, the force required to move</p><p>an object sliding on the ground and creating friction, is equal to the weight of the</p><p>object times a friction coefcient, which depends on the surface contact between</p><p>6.1 LAND TRANSPORTATION 199</p></li><li><p>the object and the ground. The friction factor is small when the surfaces are smooth,</p><p>such as steel on oiled steel, and is large when the surfaces are rough, such as lumber</p><p>on a gravel road. Friction is also harmful as it creates heat, and wears out the</p><p>objects. An engineer strives for fast delivery of heavy objects by using the least</p><p>power.</p><p>Before the invention of the wheel, sleds and rollers with small diameters were</p><p>used to move heavy objects, such as for the stones for building the pyramids. The</p><p>pottery wheel was an earlier invention for a different purpose, and might have been</p><p>a source of inspiration for the transportation wheel. The transportation wheel came</p><p>during the Bronze Age, and brought tremendous benets, since a well-lubricated</p><p>wheel can reduce the friction coefcient by a factor of 100 and also reduces wear</p><p>and heat generation. The oldest wheels were simple wooden disks with holes for the</p><p>axles, shown in many Sumerian pictures of clumsy chariots. A wheel has a sliding</p><p>friction between the axle and the hub, but the axle and hub have smooth and hard</p><p>surfaces that are kept clean and lubricated.</p><p>The wheel with spokes was invented later, which allowed for lighter and</p><p>swifter vehicles. The Egyptian Pharaoh on a chariot was often depicted going to</p><p>war, shooting arrows and trampling on the bodies of his enemies (see Fig. 6.1). This</p><p>kind of light, two-wheeled cart with a single horse or a pair of horses is frequently</p><p>seen on Greek vases and Chinese tomb paintings, and is suitable for speed and</p><p>maneuver. Chariot races were described in the Iliad as part of the funeral games to</p><p>commemorate the death of Patrocleus, and were also part of the racing events in the</p><p>Roman Coliseum. But the heavy four-wheeled wagon is suitable for carrying heavy</p><p>loads and people in everyday lives. Since wheels work best on smooth and hard</p><p>roads, instead of paths with large rocks and quicksand, paved roads were built in</p><p>FIGURE 6.1 Pharaoh on chariot.</p><p>200 CHAPTER 6 TRANSPORTATION</p></li><li><p>ancient Mesopotamia, Egypt, and Crete. The Romans built great road systems, suit-</p><p>able for conquests and for bringing resources.</p><p>The chariots and other wheeled cars were greatly improved with the inven-</p><p>tions of the differential gear on the axle, and of ball bearings. When a vehicle with</p><p>two wheels sharing a single solid axle enters into a turn, the two wheels must</p><p>revolve at the same rate, but the outside wheel needs to travel a longer distance than</p><p>the inside wheel, which creates sliding and friction. The differential gear allows the</p><p>outside wheel to revolve faster than the inside wheel, and makes possible a smooth</p><p>turn without sliding. Ball bearings were found in early Roman ships. The rst patent</p><p>for ball bearings was awarded in Paris in 1869. They change the sliding friction</p><p>between two surfaces to the much smaller rolling friction of balls.</p><p>Railroads appeared in Greece as early as 600 BCE, in the form of 6 km of</p><p>grooves in limestone to transport boats across the Corinth isthmus, using power</p><p>from slaves. Wooden wagon ways were used in England by 1650 for transporting</p><p>coal from mines to canal wharfs for boats. These roads were made of cast iron</p><p>plates on top of wooden rails. The Surrey Iron Railway in London opened in 1803,</p><p>and featured a horse-drawn public railway on cast iron, and later on wrought iron</p><p>rails. When the steam engine arrived, the rst steam trains were introduced in 1825</p><p>by George Stephenson. The connection of the North American continent from</p><p>Atlantic to Pacic was celebrated in Promontory Point Utah in 1869, where the</p><p>Union Pacic and Central Pacic railroads met and the Golden Spike was struck, to</p><p>form the First Transcontinental Railroad.</p><p>The California Gold Rush began in 1848 when John Sutter discovered gold in</p><p>a creek. The Forty-Niners were some 300,000 people who went from the East</p><p>Coast of America to the West, perhaps half by land and half by sea. The land travel-</p><p>ers covered 5000 km by an assortment of vehicles, including the Conestoga wagon</p><p>that was 7m long and could carry a load of 5 tons. It was drawn by six to eight</p><p>horses or oxen, and could have a top speed of 25 km/day. So this journey from New</p><p>York to San Francisco would take something like 200 days. The Forty-Niners might</p><p>also have sailed south to the Cape Horn, and then north to San Francisco, covering</p><p>30,000 km in 58 months. A combination sealand route was to sail to Panama,</p><p>cross the isthmus on land, then take another ship to San Francisco. This slow travel</p><p>was dramatically changed on June 4, 1876, when an express train called the Trans-</p><p>continental Express left New York City and arrived in San Francisco in only 83 h</p><p>and 39min! The railroad opened the American West, and accelerated the population</p><p>movement and economic growth. Steam locomotives require numerous workers to</p><p>load coal and remove ashes, and to maintain the boilers and pistons; locomotives</p><p>are sooty and particularly troublesome in crowded metropolitan cities. Diesel trains</p><p>used diesel engines to generate electricity from kerosene, and replaced the steam</p><p>trains after World War II. Electric trains are much cleaner, and were adopted in the</p><p>cities as soon as they became available.</p><p>6.1.2 Aut...</p></li></ul>