I also give popular mathematics enrichment talks on the maths of chocolate fountains.
Abstract: Chocolate fountains are popular features at special events. But why do they never use white chocolate? Would they work with water? And why, when the chocolate falls, does it fall slightly inwards? In this most delectable of studies, we investigate the trade-off between accuracy and simplicity in models used by commercial chocolatiers. In different geometries of the fountain, we solve the governing equations—mostly analytically—and compare these results with observations from our own fountain experiments. We find that, with some limitations, our models are in fact good for a number of non-Newtonian fluid problems. Marshmallows are, sadly, not provided.
Published article (open access):
The fluid dynamics of the chocolate fountain.
European Journal of Physics 37 (1), 015803.
Some nice write-ups in the media:
- The Washington Post: Someone finally looked into the physics of chocolate fountains
- Daily Mail: The physics of a chocolate fountain: Curtains of melted goo pull inwards because of surface tension
- Smithsonian Institution: Chocolate fountains are great for physics lessons
- Irish Examiner: One student with a sweet tooth finally explains the magic behind chocolate fountains
- PopSci.com: A chocolate fountain can introduce kids to complex physics
- Birmingham Mail: Chocolate fountain mystery: PhD student works out why liquid cocoa pours inwards
- UCL press release: Exploring the physics of chocolate fountains
And some interviews on the radio:
- BNR News Radio in the Netherlands: Als je van wiskunde geen chocola kunt maken, draai het dan om *
- Heart Breakfast with Ed & Rachel: Chocolate? It’s Good But What Else Can We Fountain?
* Guide to Dutch puns: In Dutch you can say “I cannot make chocolate out of something”. This means that you don’t understand it at all. So, the headline reads: If you cannot make chocolate out of maths, do the reverse. And ‘spanning’ (= tension) can also mean the state of being excited. (Or it can mean stress, as Google suggests). Thanks to Mark Beekhuis at BNR for translating!
Older versions of the project:
- The fluid dynamics of chocolate fountains: synopsis
Latest version: 14/07/2012
- The fluid dynamics of chocolate fountains: full MSci project
Latest version: 20/03/2012. This contains some mistakes which have been fixed in the published paper, but also contains some more problems we looked at, and some more explanation of many of the steps.
If you notice any mistakes, or have any questions, then please email me.