Episode Details

00:00 // Welcome: What Is the Real Scientific Method?

Uploaded 22-09-26

03:44 // A Bizarre Discovery: The Sound of a Cracking Whip
06:48 // The Secret to Actually Cracking a Whip
09:26 // The Mysterious Chain Fountain
11:35 // Ancient Whips and Supersonic Dinosaurs
14:32 // 1927: Proving Whips Break the Sound Barrier
20:36 // Naive Physics: Energy, Momentum, and Where They Fail
29:43 // Building the Real Mathematical Model
37:40 // Simulations That Nail the Data Perfectly
41:04 // Solving the Twice-the-Speed-of-Sound Puzzle
47:12 // From Sperm to Octopuses: Why This Math Matters

Watch the Q and A session here: https://youtu.be/LxlmVEKXa8w

A cracking whip is invariably surprising. What generates such a stunning sound? In this lecture, through simple demonstrations of whips and chains on a pulley, Professor Goriely builds simple models to explain the extreme acceleration that takes place in the motion of ropes.

In particular, he shows how these models have solutions that blow up to infinity and learns, like the dinosaurs did, how to tame these infinities to produce a stunning crack.

This lecture was recorded by Alain Goriely on the 15th of September 2026

Alain Goriely is a mathematician with broad interests in mathematical methods, mechanics, sciences, and engineering. He is well known for his contributions to dynamical systems, mathematical biology, as well as fundamental and applied mechanics. He is particularly well known for the development of a mathematical theory of biological growth, culminating with his seminal monograph The Mathematics on Mechanics of Biological Growth (2017).

He received his PhD from the University of Brussels in 1994 where he became a lecturer. In 1996, he joined the University of Arizona where he established a research group within the renowned Program of Applied Mathematics. In 2010, he joined the University of Oxford as the inaugural Statutory Professor of Mathematical Modelling and fellow of St. Catherine’s College. He is currently the Director of the Oxford Centre for Industrial and Applied Mathematics.

In addition, Alain has enjoyed scientific outreach based on problems connected to his research, including tendril perversion in plants, twining plants, umbilical cord knotting, whip cracking, the shape of seashells, brain modelling, and he is the author of a Very Short Introduction to Applied Mathematics (2017). His work has been recognized by a Sloan Fellowship, a Royal Society Wolfson Research Award, the Cozzarelli Prize from the National Academy of Sciences and the Engineering Medal from the Society of Engineering Sciences. He was elected as a Fellow of the Royal Society in 2022.

The transcript of the lecture is available from the Gresham College website: https://www.gresham.ac.uk/watch-now/cracking-whip

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