This video introduces how deeply automobiles are embedded in our lives through the daily life of K, a student at Seoul National University, exploring the origins and development of the automobile and explaining how the internal combustion engine works. Finally, he discusses the advances in modern automotive technology and the future of transportation.
Mr. K, a student at Seoul National University, wakes up early in the morning and rides his father’s car to Dongcheon Station. He then takes the Sindang Line to Gangnam Station and transfers to Line 2 to arrive at Seoul National University’s entrance area, where he takes a shuttle to class. Like Mr. K, most modern people rely on transportation such as cars, subways, and buses in their daily lives. The most common of these modes of transportation is probably the automobile – if you doubt it, step outside! What distinguishes the automobile from other modes of transportation? How did the automobile come into existence? How do cars function as transportation? Let’s find out.
To distinguish cars from other forms of transportation, let’s first understand what transportation is. If you think about buses, airplanes, ships, etc., a mode of transportation needs to be able to move people to where they need to go, and transport cargo to where it needs to go. Conversely, any device that can carry people and cargo, and has mobility, can be considered a mode of transportation. One of these modes of transportation, the automobile, only functions on land. However, we cannot yet distinguish between cars and subways based on the fact that they function on the ground. What differentiates them? In general, subways are much larger than cars, but we can’t use that as a criterion, because the criteria for how big they should be is vague, and it’s possible to build a car the size of a subway. “Only runs underground” isn’t a good criterion either, because subways have sections that run above ground, and cars can travel underground. You could consider “electrically powered” because subways are powered by high-voltage lines, but the existence of electric vehicles makes this criterion irrelevant. Instead, we should note that subways can only travel “where there are overhead power lines,” which means that they only travel where there are railroad tracks. If we satisfy “does it only travel in a defined area?”, then we can split it into subways, and if not, cars. In short, a car is a mode of transportation that only moves on the ground, while a subway is a mode of transportation that can go anywhere on the ground.
These cars didn’t just fall out of the sky one day. Transporting goods and people has always been important, which led to the invention of the wheel about 6,000 years ago. While the invention of the wheel made these tasks easier than before, it still required a lot of labor. This inconvenience lasted until 1765, when Watt improved the steam engine. In 1769, French army engineer Nicolas Joseph Quignot developed the first three-wheeled steam tractor for pulling wagons. This was the beginning of the automobile, a vehicle that generated its own power. The first automobiles, steam-powered cars, had large, heavy boilers and took a long time to power up. These problems were solved by changing the way power was generated. Electric and gasoline-powered cars emerged from this process. You might be thinking, “What electric car?” but, surprisingly, the first electric car appeared in the mid-19th century. Gasoline cars began with the development of the internal combustion engine in 1860 by Renault, a device that burns fuel internally to generate power. It wasn’t until Otto and Daimler invented a practical internal combustion engine that gasoline cars were made in earnest. Interestingly, the gasoline car was the least popular of the three at the time, because early gasoline cars were much more prone to breakdowns due to the complexity of their mechanisms and were not easy to maintain. However, after repeated improvements and the introduction of the conveyor belt by Ford in 1913, which allowed for mass production of cars, the gasoline car dominated the other two. Most cars today are gasoline cars, the winner of the three-way battle. However, none of the three aforementioned types of cars have been able to achieve the goal of “transportation without people,” which was the idea behind the emergence of the automobile. To make this happen, Google, a global company, and Tesla, a leading electric car company, are currently working on driverless cars.
Cars have come a long way to become an essential form of transportation in modern society. At the beginning of the 20th century, cars were mainly reserved for the upper class, but as mass production technology improved and prices dropped, they became more accessible to the masses. In particular, Henry Ford’s Model T played an important role in popularizing the automobile. The popularization of the automobile also had a major impact on social structure and urban planning. With the expansion of roads and highways and the development of suburban areas, the automobile freed individuals to move around. The development of the automobile industry also became an important pillar of economic growth, creating countless jobs. More than just a means of transportation, the automobile has become deeply embedded in the economy and culture of modern society.
How do today’s mainstream, gasoline-powered cars get the power to transport people and cargo? As mentioned earlier, it’s with the help of the internal combustion engine. The principle of how an internal combustion engine gets its power from oil is basically simple. It explodes the oil inside and converts the energy it gets into kinetic energy. To understand the process in more detail, let’s take a look at a type of internal combustion engine that Otto and Daimler developed independently: the four-stroke cycle engine.
Let’s start by understanding what a four-stroke cycle engine is: a stroke is the distance traveled by a piston in a cylinder. Cycle comes from the English word ‘cycle’, which means to circulate or turn. So, a four-stroke cycle engine is a power generating device that uses four piston movements as a unit of circulation. Consistent with this interpretation, a four-stroke cycle engine generates power in four stages: intake, compression, detonation, and exhaust.
In the intake stroke, the intake valve opens and the exhaust valve closes. As the piston descends, the air pressure inside the cylinder becomes lower than the outside air pressure, and this pressure difference forces air or a mixture of air and fuel into the cylinder. This is similar to what happens when you pull back the piston on an unplugged syringe.
In the compression stroke, the piston rises with both the intake and exhaust valves closed. As the piston rises, the pressure and temperature inside the cylinder naturally increase, and the density increases. Before the piston peaks, an explosion process occurs, which depends on what was put into the cylinder during the intake stroke. If it’s just air, the process will spray the fuel into the cylinder as tiny particles like a mist. If the fuel is diesel, the spraying will cause an explosion, but if not, a mixture of air and fuel will follow. In the case of a mixture of air and fuel, a small fire is ignited, literally causing an explosion. This is realized by a device called a spark plug, which is mounted on top of the cylinder. The process is similar to plugging the hole in a syringe full of air and pressing down hard with a piston.
In the detonation stroke, the high pressure of the gas burned in the compression stroke pushes the piston down. The work gained is greater than the work used in the compression stroke, meaning that the internal combustion engine is actually powered during this process. As the piston descends, the pressure of the gas in the cylinder decreases, and the gas spreads inside the cylinder. Before the piston reaches its lowest point, the exhaust valve opens to let the gas escape. This is similar to the situation where air suddenly comes out of a syringe when you suddenly open a hole that has been plugged.
In the exhaust stroke, the piston rises with the exhaust valve open. As the piston rises, the pressure of the gas inside the cylinder becomes greater than the outside air pressure, causing the gas to escape. When the piston reaches near its peak, it repeats the process again, starting with the intake stroke, and the four-stroke cycle engine is powered.
In this article, we’ve learned about one of the most common forms of transportation around us: the car. It has become a tool that most modern people use every day. However, we’ve gotten so used to them that we’ve lost sight of what they really are. To understand what a car is, we first looked at the common characteristics of transportation and analyzed the difference between a car and another mode of transportation that moves only on the ground, the subway. As a result, we learned that a car is a device for transporting people and cargo on an undefined route. We then examined the historical context in which automobiles emerged. Next, we looked specifically at how gasoline-powered cars are powered by internal combustion engines, using the four-stroke cycle engine as an example.
The automobile is deeply entrenched in modern life, and its importance will continue to grow. As technology advances, cars are becoming more efficient and environmentally friendly. With the introduction of innovative technologies such as electric, hydrogen, and self-driving cars, the automotive industry is entering a new era. These changes are fundamentally altering the way we get around and raising expectations for the future of transportation. In the end, cars will continue to evolve beyond just a means of transportation to become an important part of enriching human life.
