As teachers we often find inspiration in the most unusual of places and this is no exception. I was at Green Man Festival in Wales enjoying my summer holiday and some local university students were sharing inspiring science with the festival goers. ‘Oobleck’ was something I had not heard of and, as a science teacher, I was curious. Known to many as ‘cornflour gloop’ or slime I soon discovered this stuff is amazing. It has some fascinating and unusual properties which drill down into our understanding of the properties of solids and liquids.
But where did the unusual name of oobleck come from? Apparently this ‘cornflour gloop’ had been named oobleck after the green substance that falls from the sky in the Dr.Seuss book ‘Bartholomew and the Oobleck.’ On hearing this, I was immediately excited as ever since loving ‘Green Eggs and Ham,’ as a small child, I have loved Dr Seuss. I couldn’t wait to read the story and make some oobleck back in school.
In the story the king grumbles at the sky and it is soon revealed that he is bored of the weather. He has grown weary of the wind and the rain (currently I know how he feels) but even the snow and the sunshine. He sets his royal magicians the task of creating a new type of weather and after lots of hard work they eventually produce oobleck which rains down from the sky. This is where the problems start!
Once children have explored oobleck, they can imagine the chaos it would cause even before reading about it in the book. As with many a great story, there is an unassuming character, Bartholomew a page boy, who comes to the rescue. He saves the whole kingdom from disaster bringing the story to a satisfying ending and reminding us to appreciate what we have.
I am pleased to say that children and adults alike have been as curious and interested in oobleck and the Dr Seuss story as I have been.
Oobleck is simply a mixture made with roughly 2 parts cornflour to 1 part water and it acts like a solid under force and a liquid when it is not under force. Like a liquid, it can be poured and takes the shape of its container. Its more unusual properties mean it can also be picked up, rolled into a ball and kept like this as long as you continue to manipulate it and apply force. As soon as you stop applying force it will ooze between your fingers like a liquid. You can also poke, hit or tap the surface without making it splash. It really is an amazing substance to explore and I would encourage anyone to give it a try.
My science club were the first group of children I introduced to oobleck and it lead to far more investigation than I had initially planned for. We soon discovered that vibrations on a loud speaker could make the substance ‘dance’. As the cone on the load speaker vibrated, the substance would rise and come together creating what looked like little slime creatures which would jump and wriggle around. How amazing is that!
We also found a video of John Tickle from Brainiacs walking on custard. Since shop bought custard contains large amounts of cornflour, it has the same properties as oobleck. Naturally the next question from the children was: Can we walk on oobleck? With a little help we built a trough to fill with oobleck and we took it in turns to walk across it. Yes, you can indeed walk on oobleck. As long as you keep moving quickly, it will act like a solid and your feet will stay on top. Stop moving and it will act like a liquid meaning your feet will quickly sink in.
I learnt that oobleck is actually a Non- Newtonian fluid as unlike other fluids it changes its viscosity (how thick it is) when force is applied to it. Newtonian fluids, such as water, do not change viscosity when force is applied. There are other non-Newtonian fluids such as ketchup which becomes less viscous (or less thick) when you shake it. This is why shaking the ketchup bottle does indeed help the sauce flow out.
The learning didn’t stop there as the science club went on to find out about a new Non-Newtonian fluid that had been discovered in England called D3O. Its properties mean it can be used for a wide range of protection purposes and it is a really interesting material for children to explore.
The children in that the first science club had so much fun and exploration from this simple substance that they ended up showcasing it at a Big Bang Science Fair in London which bought the joy and wonder of oobleck to even more children. When I think back on this, it reminds me that awe and wonder does not always have to come from the things that go whizz and bang. Sometimes it comes from something a little unusual that gets us thinking and, of course, a good story.
For support with making meaningful links between science and English have a look at the Linking science and English programme. The programme is also available as in-school training. Please contact firstname.lastname@example.org for more information.