King's Factor Lecture: Vibrating plates and salt patterns

Calling all maths students from GCSE to A Level to university. Welcome to the King's Factor Lecture, our annual mathematics outreach event, highlight the exciting work done by STEM researchers at King's! Delivering the 2026 lecture is Dr Jean Lagacé, Lecturer in Analysis in the Department of Mathematics.

Talk description
Ernst Chladni was travelling throughout Europe in the early 19th century, showing off his discovery: salt spilled on a plate would form into pretty patterns if the plate was made to vibrate. This phenomenon, already known to violin-makers, fascinated many people: Napoleon even offered a reward of 3000 Francs to whoever could explain why this happened.

Unbeknownst to Chladni (or anyone really) at the time, the description of these phenomena even play a major role in our current understanding of quantum mechanics, and it is through mathematical language that we can manage to link the two. In this lecture, we will recreate Chladni's experiment and see for ourselves why it happens.

About the Speaker

Dr Jean Lagacé has been lecturing at KCL since 2022, after completing his PhD at Université de Montréal (Canada) and holding research positions at UCL and Bristol. His research is in Spectral Geometry, a branch of mathematics specialised in the study of vibrations and their relations to shapes.

Additional information

This event is aimed at those aged 16+. Younger attendees are welcome, but please note that attendees under the age of 14 must be accompanied by a responsible adult. For school groups, tickets are limited to 20 students per booking, to ensure a larger number of schools can attend. If you are aged 14–18 and booking for yourself, please check with a parent or guardian before booking your place.

Registration for this event will take place in reception in the main Strand Building entrance. This is on the Strand, the opposite side of St Mary Le Strand Church from Bush House. Refreshments will be served in the Engineering Quad Labs and the Lecture will take place in the Edmond J. Safra Lecture Theatre.

This event is organised by the Department of Mathematics at King’s College London, together with the Faculty Outreach Team. If you have any questions or would like any further details, please email nmes-outreach@kcl.ac.uk.