On Wednesday the 26th of September, members of the F-Block took part in the weekly Modern Language Enrichment. This week’s language was German. In this Enrichment, we did an experiment to discover the wonders of Oobleck. Oobleck, created by Dr Seuss in ‘Bartholomew and the Oobleck’, is a sticky green substance which is known as a Non-Newtonian fluid. A Non-Newtonian fluid is a fluid that does not follow Newton's Law of Viscosity. This means that when a force, for example, poking, rolling or stirring, is applied to it, the viscosity (resistance to flow) of the fluid increases.
Ingredients to do this experiment: one box of corn starch, a large plastic basin, a spoon and water.
Method: Firstly, mix the corn starch into the water in the ratio 2:1. Then, dip the spoon into the mixture. Next, scoop up the mixture and lastly, try making a ball with your hands. Observe what has happened in each of these steps.
Observations: When the spoon was in contact with the mixture, it was solid, however, when we spooned the mixture out of the basin, it turned into a liquid within seconds. When we tried to form a ball with the mixture, it solidified and formed a ball. However, when we just left it in our hands, it turned into a liquid and slowly dribbled off our hands, back into the basin.
In this experiment, the water and starch did not dissolve or chemically bond with each other. Non-Newtonian fluids do not have a constant viscosity, but behave like a solid, and sometimes a liquid, depending on the forces acting on them. Two other examples of Non-Newtonian fluids are custard and ketchup.
This experiment was run by Mr Brown and Mr Franke, this year’s German Assistant, who is studying English and Natural Sciences at the University of Frankfurt. The lesson and the instructions for how to make Oobleck were all given in German.