Geometry: What are some examples of ellipses in nature?

Examples of Ellipses in Nature

(Current as of [current year])

How?

Definition of an Ellipse

An ellipse is a closed curve obtained by intersecting a cone with a plane at an angle that is less than the slope of the generator of the cone but greater than the slope of the directrix of the cone. Mathematically, an ellipse can be defined as the set of all points in a plane, the sum of whose distances from two fixed points (called foci) is constant.

An ellipse has two main axes:

Major Axis: the longer of the two axes

Minor Axis: the shorter of the two axes

Now let’s explore some examples of ellipses in nature and understand why they occur.

Why?

Ellipses are observed in nature due to various physical and mathematical phenomena. Some of the key reasons behind the occurrence of ellipses in nature are:

1. Planetary Orbits

One of the most famous and significant examples of ellipses in nature is the shape of the orbits of planets around the Sun. According to Kepler’s laws of planetary motion, each planet moves around the Sun in an elliptical path with the Sun at one of its foci. This phenomenon demonstrates how gravity and centripetal force influence the movement of celestial bodies.

2. Lunar Orbits

The Moon’s orbit around the Earth is also elliptical. Its distance from the Earth varies throughout the lunar month, resulting in a slightly elliptical path. This brings about changes in the Moon’s apparent size and brightness, creating the phenomenon known as the « supermoon. »

3. Celestial Mechanics

Elliptical shapes appear in various other celestial phenomena, such as orbits of comets, asteroids, and satellites around planets.

4. Stellar Ellipses

In astronomy, binary star systems often exhibit elliptical orbits around their center of mass. These systems consist of two stars orbiting each other, adhering to the laws of gravity and producing distinctive elliptical paths.

5. Craters and Impact Structures

When a large object collides with a planetary surface, it usually creates an impact crater with an elliptical shape. The kinetic energy and angle of impact combine to form an elliptical depression.

When?

Ellipses occur consistently in nature across different time scales. Planetary and lunar orbits, for example, remain elliptical over extended periods, maintaining their shape for millions or even billions of years.

Where?

Ellipses can be observed both in space and on Earth.

1. Space

The vastness of space provides us with numerous examples of ellipses. Planetary orbits present in our solar system, as well as the orbits of comets and other celestial bodies, showcase the occurrence of ellipses on a large scale.

2. Earth

On Earth, we encounter ellipses in various forms:

a. Craters: Impact craters on the Earth’s surface exhibit elliptical shapes due to the dynamics of collision as mentioned earlier.

b. Waves: Waves often have an elliptical shape, especially when observed in deep water. This shape is a consequence of the interaction between the wind, water, and underlying forces.

c. Biological Structures: Many biological structures possess elliptical shapes, such as organisms’ cross-sections or specific aspects of their anatomy. For instance, the long axis of an egg is elliptical in shape.

Who?

Nature is responsible for the creation of ellipses through physical laws and processes. The formation of ellipses involves the interplay of gravitational forces, orbits, collisions, and other natural phenomena.

The diverse examples outlined above demonstrate how different entities interact within the rules of geometry and physics to generate the elliptical shapes we observe.