In this blog post, I will explain in an easy-to-understand manner why Archimedes shouted Eureka and how buoyancy is related to inertia and density.
Eureka! Can you guess who said this? Socrates? Achilles? Tyrannosaurus? Among the similar names that sound familiar, I’m sure no one has heard of Archimedes for the first time. This great mathematician and physicist from ancient Greece is said to have realized the principle of buoyancy when he saw water overflowing while taking a bath. “Eureka!” was the joyful cry he uttered at that moment. Buoyancy is a force well known to us from the anecdote of Archimedes, but not many people can explain exactly what it is.
The definition of buoyancy is as follows: “The force that an object receives when it is submerged in water is equal to the force of the weight of the water that the object pushes out.” This definition is difficult to understand what it means just by reading it once. To understand this complex definition of buoyancy more clearly, it is necessary to first understand the basic concepts of physics. In this article, I will explain two physical properties, inertia and density, to help you easily understand the concept of buoyancy, and I will use examples to show how these properties are naturally integrated into our daily lives. Once you understand these two concepts, you will be able to naturally learn the definition of buoyancy.
First, let’s talk about the principle of nature called “inertia.” Inertia is the property of an object to maintain its original state. In other words, an object that is stationary will try to remain stationary, and an object that is moving will try to continue moving. For example, it is because of this inertia that it is difficult to move a heavy rock by pushing it. The rock tends to maintain its original state of rest, making it difficult to move it by applying force. Conversely, it is also difficult to stop a moving object. For example, it takes a lot of force to suddenly stop a bus in motion. This is also due to inertia.
Inertia is a phenomenon that can be easily observed in our daily lives. For example, when a car suddenly stops, we feel as if we are being thrown forward. This is also due to the action of inertia, which is the tendency of our bodies to maintain their original state of motion, that is, the state of moving forward. Since inertia is a property that all objects have by default, understanding it can help us better understand not only buoyancy but also other physical phenomena.
Second, I will explain “density.” Density refers to the mass per unit volume of a substance. Simply put, it is a measure of how densely the particles that make up the substance are packed together. The substances around us are divided into gases, liquids, and solids according to their density, and they exist in various forms according to their characteristics. For example, air is light because it has a low density, while water is relatively heavy because it has a higher density. Density is closely related to buoyancy. An object floats in water because its density is lower than that of water. Conversely, an object sinks in water because its density is greater than that of water.
To better understand the concept of density, let’s consider the difference between seawater and freshwater. Seawater is more dense than freshwater because it contains dissolved salt. This is why you can experience floating more easily in seawater. Even if the objects have the same volume, they receive greater buoyancy in seawater because the dense seawater pushes the objects with greater force.
Now, let’s rethink buoyancy based on the concepts of inertia and density. Buoyancy occurs in proportion to the amount of water that an object pushes out when it is submerged in water. This is called Archimedes’ principle. For example, if a ball with a volume of 10 liters is placed in a bathtub, the ball will push out 10 liters of water and occupy that much space. The force of the displaced water trying to regain its original position, i.e. the force equal to the weight of the displaced water, is buoyancy.
The principle of buoyancy is very simple, but the fields in which it can be applied are endless. The reason why ships float in water and why balloons float in the air is all thanks to buoyancy. Even the ability of submarines to float or sink in water is possible through the control of buoyancy. As such, buoyancy plays a very important role in our daily lives and in science and technology.
Finally, let’s look at the relationship between density and buoyancy in a more extreme example. What would happen if you put a 10-liter ball in a bathtub filled with mercury instead of water? Since mercury is 13 times denser than water, it generates much greater buoyancy than water. A ball that pushes out 10 liters of mercury will receive that much more buoyancy and will float more easily. As you can see, buoyancy varies greatly depending on the density of a substance, and it can be used in various scientific applications.
Now you should have a clear understanding of Archimedes’ principle and the concept of buoyancy. Science is an amazing tool that explains our world by combining simple principles like these. Buoyancy is not just the force of floating, but an important example of how the laws of nature work. I hope this explanation has helped you understand the principle of buoyancy.
There are many scientific principles around us that we don’t have to mechanically memorize if we think a little. I hope this article will make the concept of buoyancy more familiar to you.
