Why is a motor car not considered a living thing?
The best way to answer this question is to list out the characteristics of living things and then decide which of those characteristics an automobile doesn't have.
The six characteristics of living things are as follows:
- Living things are made of cells
- Living things have DNA
- Living things respond to their environment
- Living things obtain and use energy
- Living things can reproduce
- Living things grow and develop
Based on those characteristics, an automobile is not a living thing, because it is not capable of reproducing. Vehicles can be reproduced through manufacturing, but the vehicle itself isn't capable of creating a new car or a copy of itself through sexual or asexual reproduction.
Vehicles are not made of cells, nor do they contain DNA.
Vehicles are not capable of responding to the environment. The environment may provide various stimuli to the vehicle, but the vehicle will not respond unless given a command by an operator.
Vehicles do use energy, but they are not capable of obtaining their own energy. An operator must provide the fuel for the car.
Vehicles also do not grow and develop. They don't get bigger, nor do they become more complex by developing new or altered systems.
A motor car is not considered a living thing because of the definition that has been put in place for a 'living' organism. This definition is composed of seven criteria:
1. The organism maintains homeostasis, or a balance despite the change in the system around it. An example of homeostasis is the human body temperature. Despite outside changes, the human body temperature maintains at around 98.6 degrees Fahrenheit. A motor car does not maintain its temperature at all times.
2. The organism is composed of cells. A cell is a basic functional unit that makes up an organism. Motor cars do not have cells by the pure definition, but do have components.
3. The organism has a metabolism. This is a series of chemical transformations that allow an organism to function. It could be argued that a motor car does have a sort of metabolism because there is a transformation between liquid gasoline into exhaust that powers the car, but the car cannot obtain gasoline on its own or combust it on its own, preventing it from having a complete metabolism.
4. The organism can grow. Motor cars cannot grow in size or in shape unless actively modified by something else (say, a mechanic).
5. The organism can adapt to its environment. Motor cars are not capable of adapting to large changes in temperature, road conditions, daylight times or other environmental changes to operate better.
6. The organism can respond to stimuli. An example of an organism response to stimuli is the dilation of a pupil when light levels are low. Motor cars generally do not respond to stimuli.
7. The organism can reproduce. This means that the organism can create more of either itself or more of its DNA/genome/source code. Motor cars are not capable of creating more of themselves.
If a thing fails to meet any one of these criteria, it cannot be called a living organism by current definition.
In many ways, a motor car or automobile may be appear to be living. It requires a fuel source to go, it moves from place to place, and so on. However, an automobile is not living, because it does not share all of the characteristics of living things. Let's explore!
All living things have these characteristics in common:
1. They all are made up of one or more cells. Bacteria, fungi, plants, animals, and humans are all made up of one or more cells; automobiles are not comprised of any cells.
2. All living things must maintain homeostasis. Homeostasis is maintaining a stable internal balance (equilibrium). An example of homeostasis in humans is sweating or shivering. We sweat to cool ourselves down and shiver to warm ourselves up. This is our body's way of maintaining stable internal conditions; automobiles are not able to maintain homeostasis.
3. All living things are able to grow and reproduce (sexually or asexually). Since automobiles cannot grow in size or produce more offspring, they are not considered living.
4. All living things must adapt to their environment. This means that the way organisms behave, the way they look, the use of physical features, or their way of life makes them suited to survive and reproduce in their habitats. As conditions change, each individual or population must adapt to their surroundings or die. An example of this is is the hibernation of bears in the winter. Bears hibernate to adapt to a physical change in temperature. Hibernation is an adaptation that allows bears to survive the cold weather when food is scarce; automobiles do not adapt to new changes or surroundings, so they are not alive.
5. Lastly, all living things must be able to respond to stimuli. Anything that causes a living thing to react is called a stimuli. Light, temperature, sound, odor, gravity, and pressure are all examples of different stimuli that may affect living things. Since automobiles do not react in response to temperature, light, etc, they are not considered living.
While motor cars and automobiles do resemble living organisms because they move and need fuel to function, they are not "alive" because they are not made of cells, they are not able to maintain homeostasis, they do not grow or reproduce, they cannot adapt to their surroundings, and they are not able to respond to stimuli.
As you seem to have grasped, there are, very broadly speaking, two categories of things—"living" and "nonliving." Living things are things such as humans, plants, and other animals. They eat, they breathe, and they exist in our minds as having minds of their own, essentially. Nonliving things are things such as tables, chairs, and, as you correctly said, motor cars. These things do not eat, nor breathe, nor do we see them as having a will or mind of their own.
Now, why is a motor car considered nonliving? First, let's go over what makes a thing "living." In order to be considered "living," something must have four key characteristics:
It must be able to:
2. Move on its own
Let's see how this list might or might not apply to a motor car:
1. It must be able to grow.
Can a motor car grow on its own—that is, without the help of engineers or the addition of new parts? No.
2. It must be able to move on its own.
Can a motor car move on its own? Occasionally, especially when located on a hill of some sort, a motor car will move without a driver. But in this case, there is no brain telling the car to turn its wheels and therefore to travel in one direction or the other. It is simply being acted upon by other forces. Likewise, when a motor car is being driven, the car itself is not telling itself where to go. Rather, it is the human behind the wheel that is moving the car by pushing harder on the gas pedal and moving the steering wheel.
3. It must breathe.
Does a motor car breathe? One might argue that cars do breathe—after all, they produce CO2 gas as a waste product, just as we humans do. However, this CO2 production is a result of a combustion reaction that happens as gasoline is fed through the car's engine. The motor car, despite "exhaling" CO2 gas, has no lungs, and is not "inhaling" O2, as we do.
4. It must be able to reproduce.
It is certainly true that there are a lot of motor cars on this planet. However, this excess of cars is not due to two cars mating to produce a baby car, which will then go on to become a full-grown motor car. Instead, the presence of all of these cars is a result of mass manufacturing—factories producing tens of thousands of the same cars and releasing them to the public.
In summary, a motor car is NOT considered living, because it cannot grow, move, breathe, or reproduce on its own.