This is a method used in applied mathematics, physics and engineering.

Let me start by saying that, unlike the other articles in this blog, this post will be quite technical, and it might be challenging for the lay public. Anyway, I invite you to read and ask me questions in the comments if something is unclear.

The Buckingham π theorem can be used to find the “hidden” relation between physical quantities that describe a given phenomenon. It relies on the principle of dimensional homogeneity which basically tell us that we can’t sum apples with melons.

I will use an example to explain the theorem. Let’s consider a pendulum, and suppose that we aim to find its period (i.e. the time that the pendulum takes to complete an oscillation). Our purpose is to find an equation describing how the period depends on the physical quantities involved.