What Is the Sphere in the Eyes of Islamic Mathematicians? (Children)

Hello, Little Friend! Let’s Talk About the Sphere

Today we will discuss a very interesting topic: the sphere! What do we mean by sphere, where is it used, and what did great thinkers of the past say about it? I will try to explain these to you. Let us begin by defining the sphere. A sphere is a round object. Think of a football: there is a single center point that is equidistant from every point on its surface. This is exactly what defines a sphere. Great scientists have learned much to help us understand this concept better. Let us now look at what they said!

How Did Great Thinkers Define the Sphere?

Great scientists from the past said wonderful things about the sphere. For example, the scholar Al-Khwarizmi described it as: “A sphere is a solid in which all lines extending from a central point to its outer surface are of equal length.” Another scholar, Al-Biruni, explained it thus: “A sphere is a round object enclosed by a single surface, where all distances from the center to the outer surface are equal.” Ali Kuşçu provided an even more detailed description. He defined the sphere as a three-dimensional object and said: “The lines extending from the center to the surface are called radius, and the long line connecting two opposite points through the center is called diameter.” Isn’t that fascinating?

The Sky and the Importance of the Sphere

Now let us look at the sky. In ancient times, people learned much about stars and planets by observing the heavens. They used the properties of the sphere to do so. For instance, they imagined the sky as a giant sphere, as if the stars were fixed on its surface. Imagine holding an orange and placing small dots on it—that is how they tried to estimate the positions of visible stars. Using this knowledge, they studied special shapes called spherical triangles. Is it not a wonderful idea to view the sky through mathematics?

Instruments Used to Understand the Sky

Scientists created various instruments to study the sky more closely. For example, there is something called a “celestial sphere”—a spherical model showing the positions of stars in the sky. There is also an instrument known as the “ring sphere,” which they used to observe movements in the heavens. Another device, called an “astrolabe,” helped them determine the positions of stars. The Ottoman scientist Taqi al-Din built such instruments. What brilliant minds they were!

This is not all! The sphere was also a vital model for understanding the Earth’s surface. Geographers created globes to represent the map of the Earth. You know those large round globes you see in school—those are terrestrial globes! They also made glass spheres called “burning spheres.” These spheres were used to focus sunlight to a single point. Thus, the sphere proved to be an excellent tool for understanding both the heavens and the Earth.

The sphere is an extremely important concept in science. Ancient people used it to learn about the motion of stars, the shape of the Earth, and the positions of planets. Mathematicians, astronomers, and geographers learned much from the sphere. Islamic mathematicians were pioneers in this field. Their work shed light on future developments in science. That is why this round shape we call the sphere is far more valuable than we might think!

Isn’t this a fascinating topic? Engaging with science and learning new things helps us understand the world. So, try to learn even more about this wonderful world. Perhaps one day you too will become a great scientist!