Complexity Explorer: Fractals and Scaling

with  David Feldman
Class Central Course Rank
#2 in Subjects > Mathematics

We will begin by viewing fractals as self-similar geometric objects such as trees, ferns, clouds, mountain ranges, and river basins.  Fractals are scale-free, in the sense that there is not a typical length or time scale that captures their features.  A tree, for example, is made up of branches, off of which are smaller branches, off of which are smaller branches, and so on.  Fractals thus look similar, regardless of the scale at which they are viewed.  Fractals are often characterized by their dimension.  You will learn what it means to say that an object is 1.6 dimensional and how to calculate the dimension for different types of fractals.

In addition to physical objects, fractals are used to describe distributions resulting from processes that unfold in space and/or time.  Earthquake severity, the frequency of words in texts, the sizes of cities, and the number of links to websites are all examples of quantities described by fractal distributions of this sort, known as power laws.  Phenomena described by such distributions are said to scale or exhibit scaling, because there is a statistical relationship that is constant across scales.

We will look at power laws in some detail and will give an overview of modern statistical techniques for calculating power law exponents.   We will also look more generally at fat-tailed distributions, a class of distributions of which power laws are a subset.  Next we will turn our attention to learning about some of the many processes that can generate fractals.  Finally, we will critically examine some recent applications of fractals and scaling in natural and social systems, including metabolic scaling and urban scaling.  These are, arguably, among the most successful and surprising areas of application of fractals and scaling.  They are also areas of current scientific activity and debate.

This course is intended for anyone who is interested in an overview of how ideas from fractals and scaling are used to study complex systems.  The course will make use of basic algebra, but potentially difficult topics will be reviewed, and help is available in the course discussion form.  There will be optional units for more mathematically advanced students and pointers to additional resources for those who want to dig deeper.

Syllabus

1. Introduction to fractals. Self-similarity dimension. Review of logarithams and exponents.

2. Box-counting dimension. Further examples of fractals. Stochastic fractals.

3. Power laws and their relation to fractals. Rank-frequency plots. How to estimate power law exponents.

4. Empirical examples of power laws. Other long-tailed distributions: log normals and stretched exponentials. Implications of long tails.

5. Mechanism for generating power laws. Rich-get-richer phenomena. Phase transitions. Other mechanisms.

6. Metabolic scaling. West-Brown-Enquist scaling theory.

7. Urban scaling.

39 Student
reviews
Cost Free Online Course
Subject Mathematics
Institution Santa Fe Institute
Language English
Certificates Certificate Available
Hours 2-4 hours a week
Calendar 7 weeks long

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Reviews for Complexity Explorer's Fractals and Scaling 4.9 Based on 39 reviews

• 5 stars 90%
• 4 stars 10%
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Did you take this course? Share your experience with other students.

• 1
5.0 2 years ago
completed this course.
I highly recommend this course.

The structure of the course and the presentation are superb.

For example, the clever balance of detailed explanations and of general explanations of a few topics, provides quite an interesting (and useful) perspective of the material.

Exciting, interesting, thought-provoking fun on topics that are relevant to a wide range of disciplines (and growing).

-steve

4 people found
5.0 2 years ago
by completed this course.
This was a great class as in introduction to fractals and scaling. The metabolic scaling section was fascinating, and has encouraged me to do more in-depth reading and research on the subject. I'm definitely looking forward to the next Complexity Explorer course!
1 person found
4.0 2 years ago
by completed this course.
Good course, really peaked my interest in the topics presented, good introduction! Could use some more hands on computational exercises to connect better with the material but was otherwise a very good course.
2 people found
5.0 2 years ago
by completed this course, spending 3 hours a week on it and found the course difficulty to be easy.
Very nice course! Quite easy without going deep into math behind, without any computational assignments. But topic is rather interesting and explanations were very clear and with good examples. You can watch it on 1.5x speed easily.
1 person found
4.0 10 months ago
completed this course.
The course was very well taught by the instructor, which provided a nice overview on the subject. However, I still missed some "real -life examples" during the course, yet the instructor discussed two nice applications, i.e., metabolic and urban scaling, which I have never heard before. Maybe further examples, like stock market or large-scale structure of the Universe, would improve the course immersion even more. But taking into account the limited duration (2 months?) that such mooc should take, the content is very good and broad. Considering also that many of the attendants are not trained in the STEM field (as in my case), the introduction regarding logarithms, power laws etc. were very didactic and clarifying. Another positive point goes to the interviews, which were very insightful.

I am giving therefore a 4 out of 5, since I still believe that some points (the real life examples) could be improved a little bit, but these are just minor improvements that do not comp
The course was very well taught by the instructor, which provided a nice overview on the subject. However, I still missed some "real -life examples" during the course, yet the instructor discussed two nice applications, i.e., metabolic and urban scaling, which I have never heard before. Maybe further examples, like stock market or large-scale structure of the Universe, would improve the course immersion even more. But taking into account the limited duration (2 months?) that such mooc should take, the content is very good and broad. Considering also that many of the attendants are not trained in the STEM field (as in my case), the introduction regarding logarithms, power laws etc. were very didactic and clarifying. Another positive point goes to the interviews, which were very insightful.

I am giving therefore a 4 out of 5, since I still believe that some points (the real life examples) could be improved a little bit, but these are just minor improvements that do not compromise the overall's quality of the course at all. So, I am very thankful for Prof. Feldman for providing such nice course.

5.0 10 months ago
partially completed this course.
If you are interested in or are pursuing computer science or digital visual arts, I highly recommend taking this course. This course totally beats that one-day lesson on fractals in algebra I had in middle school. Even though the professor doesn't assume much more of a background in math than high school algebra, he takes you step by step through logarithms and power laws if you need a refresher. Even though I didn't complete the course, the first few units on fractals were not only very interesting, but I found them very complementary to my study of recursion in computer science. If you're learning to program in Java, I would recommend downloading the Processing language IDE and trying to program the fractals that the professor introduces in the course, or if you're more into graphics software, downloading Inkscape and trying out the L-systems method of producing fractals on that. This is a very gentle but interesting and applications-packed course if this is your first course in comp
If you are interested in or are pursuing computer science or digital visual arts, I highly recommend taking this course. This course totally beats that one-day lesson on fractals in algebra I had in middle school. Even though the professor doesn't assume much more of a background in math than high school algebra, he takes you step by step through logarithms and power laws if you need a refresher. Even though I didn't complete the course, the first few units on fractals were not only very interesting, but I found them very complementary to my study of recursion in computer science. If you're learning to program in Java, I would recommend downloading the Processing language IDE and trying to program the fractals that the professor introduces in the course, or if you're more into graphics software, downloading Inkscape and trying out the L-systems method of producing fractals on that. This is a very gentle but interesting and applications-packed course if this is your first course in complexity.
5.0 10 months ago
partially completed this course.
For lack of my own personal time I was not able to finish the course but the course itself has ample time to be finished. The homework is great, the easy questions make sure you get the basics down and the harder questions are challenging and within the range of what is being taught.

There are many references to real world practical usage, books, articles and software. The community of students and teacher are lively and supportive; they help out with doubts and always bring something new to contribute to the learning process in discussions.

I think that anyone who does this course may come out of it learning enough to understand what fractals are and have enough baggage to enter the more detailed and (more) mathematically challenging material on their own; or at least know exactly what is needed to advance.
5.0 9 months ago
completed this course.
I wasn't sure I'd have the time to take this course but I had taken another one taught by Dave Feldman last summer (Dynamical Systems and Chaos) and it was great. I had free time then but, having just started a job, I was more concerned about my ability to devote the necessary time to the course. I ended up giving it a go and settled on a routine of downloading the lectures and watching them during my time at the gym, which not only allowed me to focus on the lectures but made me look forward to going to the gym! I work in human computer interaction and I'm hoping to direct my research in this direction but, even if it's a tough fit and I can't find a way to integrate things, the course is incredibly rewarding in and of itself and offers tasty brain food to chew on.
4.0 10 months ago
audited this course.
I really enjoyed this course. The material was interesting and the explanations were clear. The instructor was engaging. So I feel like an ingrate complaining, especially about something that is not within hos control. But I hope you'll find a way to adjust for a presenter's left handedness. Watching the back of his hand as he wrote on the whiteboard got to be frustrating after a while.

Thank you so much for offering ordinary people the opportunity to learn such cool stuff!
5.0 a year ago
is taking this course right now.
This is an amazing course for anyone that wants to learn about this topic and does not have the time to go through all the mathematical rigour behind it. The lecturer has a natural skill to explain in a very simple way things that may seem very complicated in some textbooks or courses. You will have fun following these lectures and learn while you can hold a cup of coffee in one hand and a pocket calculator in the other to compute dimensions of fractional objects.
5.0 11 months ago
completed this course.
Great overview of the topic with excellent resources and interviews for additional directions for more the interested students. A bit light on the math, but I understand the intent on making it accessible to the largest audience. Everyone should take this course since it is a fundamental topic to the future of systems science, which pretty much encompasses everything these days
5.0 10 months ago
completed this course.
Great overview of fractals, followed by a thorough in-depth exploration of the math and concepts behind them, that of self-similarity and Power Laws. Some practical implications peppered throughout but particularly near the end of the course. I admire David's restraint in implicating too much meaning behind self-similarity, while underscoring the potential power endowed by it.
5.0 11 months ago
by completed this course and found the course difficulty to be medium.
It is a very informative and good course. The homework and solutions are helpful for students to go ahead with the test sessions and all of them help students understand the course content.

The label of Advanced level is for the study and exploration of supplementary materials.
5.0 2 years ago
partially completed this course.
I started to take the course but for reasons of time I could not finish it I am very sorry, but the time was taking the course was very interesting, I hope I can take back to thank you very much Dave was very interesting. An apology for not being able to finish thanks to SFI muchs
5.0 12 months ago
partially completed this course.
This is one of the best online course I ever had till now. Dave is simply awesome. Earlier, I was having trouble understanding Nassim Taleb's underlying mathematical philosophy which was based on Fat tails distributions. This course alleviated that trouble.
5.0 10 months ago
completed this course, spending 3 hours a week on it and found the course difficulty to be easy.
Excellent Course!! This is a highly accessible (barest minimum of Math) course on Fractals and applications on Scaling in a wide variety of scenarios. The instructor is good and he also provides many reference material for further study.
5.0 2 years ago
completed this course.
Great Course. Learned a lot from it. I found fractals very interesting, and I believe I can definitely apply that in my Artificial Intelligence project. There's lots of statistics involved, but they are not really difficult.
5.0 2 years ago
completed this course.
Good introductory course. Highly recommended for anyone interested in overview of fractals. Perhaps some additional information on generation of fractals in mathematical constructs, their basins of attraction can be added.
5.0 10 months ago
by completed this course.
This course was great. It included a good amount of math, but not too much for someone like me who hasn't taken math courses for decades. And I loved learning about the relevance of fractals to our daily lives.
5.0 2 years ago
is taking this course right now.
One of the best instructors I have heard in the last........many years!!

Real pleasure of learning,

Clear explanations,

The part if the fractal counting is a bit too long, but you know it

Thank you