Oobleck
From Wikipedia, the free encyclopedia
Oobleck is a fictional form of green precipitation invented by children's author Dr. Seuss in the book Bartholomew and the Oobleck. The word has since been used to describe a mixture of corn starch and water used to demonstrate the dilatant property of non-Newtonian fluids.
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[edit] Fictional precipitation
In Bartholomew and the Oobleck, a king bored with ordinary rain, sunshine, fog, and snow causes green precipitation called Oobleck to fall from the sky. The Oobleck proves so sticky that it gums up the whole kingdom until the day is saved by Bartholomew Cubbins, the title character from Dr. Seuss' 1938 book The 500 Hats of Bartholomew Cubbins.
[edit] Non-Newtonian fluid
The word has since been used to describe a substance that is used as a science aid to teach children about liquids and solids. This oobleck is created from cornstarch or potato flour and water in a ratio between 4:2 and 3:2. Though initially it acts like a viscous liquid, applying pressure quickly will make it appear to be a solid for a short time. The oobleck also behaves unlike conventional solids or liquid when thrown in the air, molded, heated, or vibrated. Substances that become more viscous when agitated or compressed are a subset of non-Newtonian fluids called dilatants.
A dilatant material (also termed shear thickening) is one in which viscosity increases with the rate of shear. Such a shear thickening fluid, also known by the acronym STF, is an example of a smart material, a class of materials that respond to changes in the environment. Oobleck readily demonstrates the dilatant effect.
The opposite of a dilatant material is a pseudoplastic.
[edit] Glurch
The related Glurch is the nickname given to a polymer substance created in many middle school science courses. It consists of starch, glue and food coloring. It is used to show the process of polymerization.
[edit] External links
- Non-Newtonian fluid experiment at YouTube on Brainiac: Science Abuse
- "Outrageous Ooze", "Science Explorer", Exploratorium
Oobleck is also known in the Uk as "Goop" in many primary and nursery schools. It is made from cornflour (cornstarch) and water, with or without food colouring.
