An undergraduate laboratory experiment on measuring the velocity of light with a catastrophic machine

TL;DR

This paper presents a low-cost undergraduate experiment to measure the speed of light using electrostatic and magneto-static methods, emphasizing a catastrophe theory approach, and demonstrates its educational effectiveness at an international Olympiad.

Contribution

It introduces a novel, inexpensive experimental setup for measuring the speed of light based on catastrophe theory, suitable for high school education.

Findings

Achieved percent-level accuracy in measuring the speed of light.

Successfully used the setup in an international physics Olympiad with high school students.

Demonstrated the educational value of catastrophe theory in physics experiments.

Abstract

An experimental setup for electrostatic measurement of $\varepsilon_0$, separated magneto-static measurement of $\mu_0$ and determination of the velocity of light $c=1/\sqrt{\varepsilon_0 \mu_0}$ according to Maxwell theory with percent accuracy is described. No forces are measured with the experimental setup therefore there is no need of a scale and the experiment price less than \pounds20 is mainly due to the batteries used. Multiplied 137~times, this experimental setup was given at the fourth open international Experimental Physics Olympiad (EPO4) and a dozen high school students did very well. This article, however, focuses on the catastrophe theory, which is the basis of the methodology.