Wired took a deeper look into the science behind Oobleck, one of the most common classroom STEM activities:
Of course, the most famous force applied to oobleck is the weight of a person slamming their foot down as they run over a vat filled with the stuff. You can find plenty of videos on Youtube of people repeating this amazing feat, including the one above. It’s not just little children, college students, and Ellen viewers who are impressed. Explaining all of oobleck’s properties is actually the subject of serious scientific investigations.
In 2012, researchers at the University of Chicago published a paper where they described the battery of experiments they performed on oobleck (you can watch a video of their tests below). It’s hard not to be impressed by all the science these guys are doing on some bizarre stuff I used to play with as a kid: Lasers! High-speed cameras! X-ray machines! Their lab has got it all.
After measuring all the forces and deformations involved inside of oobleck, the researchers think they know how it is able to generate the support for messiah-like party tricks. If you hit oobleck hard and fast, the cornstarch particles get shoved together, bunching up like snow in front of a snowplow. This creates a quasi-solid column just below your foot, which can support your weight. But if you stop moving, you stop applying force and the oobleck returns to a liquid state.
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