Comparing Mandelbrot and Julia Sets

Benoît Mandelbrot coined the term "fractal" in 1975

Benoît Mandelbrot and Fractals

Benoît Mandelbrot coined the term “fractal” in 1975 to describe the naturally occurring, never-ending, infinitely complex, self-similar, geometric patterns, which look “fractured” or “broken”. Fractals are important because 1) nature creates fractals 2) They are an example of how a few simple rules can create a wildly complex system.[1][2][3]

Big Brains. Small Films. Benoît Mandelbrot, The Father of Fractals | IBM. IBM took a chance on Mandelbrot’s revolutionary way of thinking, and this video is a quick retelling of that relationship.

TIP: See Conway’s Game of Life, the Standard Model of Particle physics, or our page on Complex systems for more examples of simple rule sets creating complexity.

FACT: The colors and shapes you see in fractals are math-based. They are representations of naturally occurring complex shapes, not artistic impressions of shapes. Color choice is meant to help people to see the complex patterns so while it’s math based, it is atheistic in this one way.

Key Terms for Understanding Fractals:

  • Iteration v. Recursion (simple): In overly simple terms, recursion and iteration perform the same task, they “loop” and “repeat” to solve a complicated task one piece at a time, and combine the results. Iteration loops the task until it is done, Recursion factors in the previous result. Learn more.
  • Complex and Imaginary Numbers and Fractals: A number line has positive and negative real numbers. If we intersect that line we can chart complex imaginary numbers. If we graph this with a function that creates fractals, and then plots those numbers, it creates the fractal images we see.
  • Roughness: One can’t accurately measure a coastline (Coastline paradox) due to its fractal nature, but one can measure its “roughness”. Roughness expresses the “fractal dimension” of a curve.[4]
  • Fractal Dimensions: Shapes like circles and squares have curves one expects to see. In between these shapes are an infinite amount of odd looking curves. Science used to disregard them until Mandelbrot pointed out that they were the a key to the universe. That is one reason why we call Mandelbrot “the Father of Fractals.”[5]

TIP: Many computer graphics are created using fractals. Most shapes we see in nature can be created with a simple function by defining roughness.[6]

FACT: A lot of today’s technology wouldn’t be possible without fractal geometry. Most electronic devices use fractal designs for space saving; some can’t even function without employing fractals.

Why are Fractals and Benoît Mandelbrot Important?

Fractals may seem artistic, but they are based on scientific principles. Mandelbrot revolutionized science, mathematics, and technology with his Fractal Geometry while working at IBM. The “art” aspect of fractals is perhaps the least interesting thing about them. Look out your window; everything that isn’t a man made standard Euclidean shape is essentially a fractal.[7] Fractals are an efficient and natural method of “growing” that nature employs liberally due to her frugality (natural selection is driven by energy efficiency). The human body is largely created from fractals, just look at how the human nervous system iterates in a recursive fashion. Hopefully, you are excited enough now to bare with the technical terms. Make sure to watch the mind-blowing videos below.

TIP: Consider buying this amazing Fractal Documentary from NOVA “Hunting the Hidden Dimension” (Amazon).

Fractals – Hunting The Hidden Dimension. This video shows how fractals are used in computer graphics to create things like coastlines and mountains.

TIP: The fractal documentary above mentions Kleiber’s law. Kleiber’s Law is based on his observation that, for the vast majority of animals, an animal’s metabolic rate scales to the ¾ power of the animal’s mass. Or, E=m¾.

Who Discovered Fractals?

Mandelbrot wasn’t the first to discover fractals. That credit should probably go to Pierre Fatou and Gaston Julia in 1918 (although Gottfried Leibniz pondered recursive self-similarity as early as the 17th century). Mandelbrot coined the term “fractal” and claimed to be the first to discover the mother of all fractals, the Benoît-named Mandelbrot set. For this reason, Benoît Mandelbrot is called “the father of fractals.” See a more complete history of fractals from WikiPedia.

TIP: The Mandelbrot set contains an infinite amount of Julia sets. Any point relates back to a Julia set, given some mathematical manipulation, which is part of the reason the Mandelbrot set is so famous. According to Scientific American, “Julia sets had been described as early as 1906 by the French mathematician Pierre Fatou. They were named later for Gaston Julia, who successfully claimed that his work on the sets some dozen years later had greater significance than Fatou’s. Mandelbrot, who was born [in 1924] in Poland, had read the work of both men and studied under Julia in the 1940’s”.[8]

Benoit Mandelbrot: Fractals and the art of roughness. Here is a Mandelbrot set, bounded to a YouTube video for 21 minutes, why not learn about fractals from the master himself?

FACT: When talking math, fractals, and systems, the word “set” means, “that which is bound within the limits of the system being considered,” for our purposes we are saying everything within the bounds of the limits of the function that creates the fractal. So in the on-page image, everything on the XY axis within the limits of our coordinates (as noted on the image). Learn more about systems.

FACT: It is impossible, for all practical purposes, to accurately measure a coastline in real life. This is because nature seems to employ recursive fractals in its design process. The closer you zoom in, the more surface area you will measure. Oh, the art of roughness, you are complex. I guess that is why you are so popular with math nerds.

What is a Fractal?

A Fractal is a never-ending self-similar pattern driven by a recursive algorithm and complex numbers.

It is a simple algorithm that, when complex numbers are introduced and plotted on a graph, creates an infinite amount of patterns that resemble the growth of branches on a tree, or the way one might think the galaxies and stars appear from a birds eye view. The shapes are self-similar so, although are infinite, they are recognizable in the same way that every snowflake is different.

The simplest example of a fractal is a Sierpinski Triangle, as featured in the video below.

How to Draw The Sierpinski Triangle: A Fractal Zoom.

TIP: Fractals are Recursive. Recursion is the process of repeating items in a self-similar way. For instance, when the surfaces of two mirrors are exactly parallel with each other, the nested images that occur are a form of infinite recursion. So a recursive algorithm is a function that loops back to the start each time and results in recursion.[9]

What is a Mandelbrot Set?

The famous Mandelbrot set is an example of using a specific recursive function to create a specific bounded fractal set that contains an infinite number of self-similar math-based patterns that are beautiful to look at. There are many different types of fractals, but a Mandelbrot set is special because every single point on a Mandelbrot set, of which there are infinite points, relates to a Julia set, which itself is infinitely recursive.

Now is probably a good time to mention that there are different types of infinity. Below is a spectacular full-length educational film on Fractals and computer graphics.

The Mandelbrot Set – Numberphile.

TIP: Iteration is a math term, but it means just what it sounds like, a repetition of a mathematical or computational procedure applied to the result of a previous application, typically as a means of obtaining successively closer approximations to the solution of a problem.[10] For instance, you may try to get to the number 2 by saying: 1 + 1/2 + 1/4 + ⅓, etc. You will never get to two, but you’ll keep getting closer with each iteration as you add the new number to the last result.

TIP: Learn more about Fractals from the very cool Fractal Foundation.


Benoît Mandelbrot coined the term “fractal” in 1975, and he is considered “the father of fractals”, that said, the story starts earlier. The mathematics behind fractals began to take shape in the 17th century when the mathematician and philosopher Gottfried Leibniz pondered recursive self-similarity, then continues to Pierre Fatou and Gaston Julia, and then onto Benoît Mandelbrot.

We have to remember that we aren’t just talking about “art”, but actually about mathematics, science, and technology when we talk about fractal geometry.


  1. What are Fractals?
  2. Fractal
  3. Fractal Geometry
  4. Coastline paradox
  5. Fractal dimension
  6. Roughness
  7. An Introduction to Fractals
  8. Who Discovered the Mandelbrot Set?
  9. Recursion
  10. iteration

"Benoît Mandelbrot Coined the Term “Fractal”" is tagged with: Fathers or Mothers of a Field, IBM

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