soap bubblesBubbles are fun, and what's more, there is loads of maths involved in them! But before all that, how about making some yourself? We had a biggest bubble competition in my year 7 class today as part of a data handling unit of work  students were in teams of 46 and we found averages, range etc It was the most fun way I've ever taught data handling  see the pics on the right! 

Here's some pics when I went to a local primary school to show them the maths behind bubbles.


Bubbles make interesting shapes when you dip different frames into soapy water. The video on the right shows what happened when we dipped a tetrahedron and cube into soapy water to liven up a year 13 saturday revision session! 

Here is a still image from the video. Can you explain why we get a cube in the middle? Why is it a bit bendy? What will happen when you dip different shapes into the water? This page aims to answer some of these questions... The best way to understand what is going on is to look at what happens when two or more bubbles meet. Here are some pictures  click on them to read the captions: 
some soapy maths
Plateau's experiments
Plateau was a blind scientist who experimented with bubbles and found that a maximum of only 3 soap films (faces) ever meet at an edge (once the bubbles have stablised). Try it for yourself! As a consequence only 4 edges meet at any point. So although the films (faces) meet at 120 degrees, the edges meet at a different angle. Can you guess what this is going to be? Well, if you dip a tetrahedron into soapy water, you can see clearly what happens! The angle between the edges is our old friend the tetrahedral angle, 109 and a bit degrees!
This explains why the cube in the middle of the cube is bendy. At a vertices, the (tangents to the) edges meet at angles of 109 degrees, not 90 degrees!

tom noddy
On the right is a brilliant video from BBC program The Code that explains all this with the help of Tom Noddy, a bubble magician! Another video of him appearing on a chat show is below. 
His website contains lots more videos, practical projects and more on the science of bubbles.

occurences in nature

You can also see these patterns in naturally occurring cracks. The following are pictures of artworks by Alberto Burri who allows materials to crack and then creates art from them.
There's loads more fun you can have with soap bubbles. How about looking at the reflections and colours? The colours a bubble goes through before popping are green, blue, magenta, yellow, green again, white, then white with black spots, then black... and then it bursts! And if you look at the reflection in a bubble, there are two images; one the right way and one upside down... why is this?
Or you could just play a bit more  maybe one day you could emulate Tom Noddy!
Or you could just play a bit more  maybe one day you could emulate Tom Noddy!