It is likely that the earliest circles were created to imitate reality (the moon, sun, and wheels) along with other things they drew without the use of special equipment. The earliest really round things made by man were most likely created on a potter's wheel. You may construct a lovely round slab and use it to draw circles. But to paint or stain a round object requires some way to fix its shape.
People have been making perfect circles for thousands of years using different methods, but probably the first known method was described by Thales of Miletus in 600 B.C. His description was so accurate that modern scientists can still use it today to make spheres under laboratory conditions. Thales' method involved rolling a ball down an inclined plane -- which is why we call such objects "spheres" today.
The ancient Greeks were very interested in mathematics and science. They asked questions about how things work and tried to answer them through experiment and logic. For example, they wondered how you could make a sphere and they decided that you could not because balls roll down hills/slopes. However, they did not give up and came up with another way to make a sphere. They used water to fill a bowl until it was half full and then threw in a rock. The rock would create a new surface for the water to roll off of and that was how they made spheres. This was thought to be something like magic since the Greeks did not understand water dynamics at all back then.
Circles have been utilized in art since man developed them. A circle is the appropriate symbol for wholeness. It is a never-ending, balanced line that is frequently used as a symbol of oneness and eternity. Circles are a symbolic response to man's quest for meaning and comprehension of time. Wholeness cannot be divided into parts, and thus no part of the whole can represent or stand for another part.
In architecture, the circle is the most fundamental shape upon which all others depend. In painting, drawing, and sculpture, the circle is the basis for all forms. The circular arrangement of plants around a central seed pod is extremely common in nature. The flower, whose reproductive organs are in the form of a sphere, serves to attract insects that will carry its seeds far and wide. In man-made creations, the circle is used in many ways including as an ornament, a container for holding or storing something else, or as a source of light. It is also used in science as a model for explaining how things work or for representing the universe because it is the only shape that contains no outside and no inside. Science uses circles in many ways including in laboratory experiments where they are essential to show what happens to objects when they are exposed to different conditions.
Circles are important in religion too. They are used in many temples around the world to represent the endless cycle of life.
Around 73,000 years ago, Homo sapiens made the world's earliest known drawing on this stone in what is now South Africa. A little rock flake the size of a house key is covered with a massive surprise: the earliest documented artwork done by a person. The image is a simple sketch of a rhino with some stick figures inside its mouth. But even after more than 100,000 drawings have been made since then, no other artist has come close to reaching such a milestone so early in history.
The key to understanding why there are so few ancient drawings is to remember that people back then didn't use pens or pencils. They used sticks and stones to mark out their territory, keep track of their possessions, and communicate with others. So it makes sense that the first artists would also use natural materials to create works of art. There are several possible sources for these early drawings, including images carved into rocks or drawn on cave walls.
One place where you can see some of the oldest drawings in the world is in the Drakenstein Local History Museum near Cape Town, South Africa. The museum has more than 7,000 pieces that were found in local mines and quarries. Many of them date back more than 10,000 years.
Camera lenses, pizzas, tires, Ferris wheels, rings, steering wheels, cakes, pies, buttons, and a satellite's orbit around the Earth are all instances of circles in real life. Circles are just closed curves that are equidistant from a defined center. They can be divided into four general types: circular, elliptical, polygonal, and irregular.
Circles have many applications in daily life. For example, when taking photographs, the photographer uses a camera lens to create a curved image on film or digital media. The optics of the lens produce a view of the world as if it were wrapped up like a ball. When making pizza, a cook rolls out a thin layer of dough onto which they place sauce and cheese, creating a round shape. Pizza wheels are made by rolling out flat disks of dough and cutting them into circles with a knife or pizza cutter. Rings are two circles that are joined together at one end; you can wear your ring all day long without worrying about sweat or oil causing the metal to rust. Cake mixes often include circular cake pans that help make delicious cakes every time.
In mathematics, the circle is the set of all points in a plane equivalent under a rotation, reflection, and translation (cyclic shift).