Wednesday, October 15, 2008

Oobleck?

Apparently there's a commercial product that has similar qualities to oobleck, the classic geek toy made from a saturated cornstarch solution. (Or is it a suspension?)
Post-Gazette: Zoombang Protects Teen Athlete's Insulin Pump

The company says its product, "Zoombang" (wowie zowie), is a "viscoelastic, shear thickening" polymer. It even references its corn starch relative in the explanation.
Zoombang Protective Gear: What's Zoombang?

They make custom garments for athletes who need extra protection because of injuries or whatever. The Post-Gazette story was about a gadget they made for a youth football player who needed to protect his insulin pump. Apparently it's the viscoelastic part that makes it protective - standard oobleck is quite rigid under stress and wouldn't protect anything from impact.

Oobleck, I just learned by Googling, is named after some goo in a Dr. Seuss book. To make it, mix about one part water with 1.5 to 2 parts corn starch. It's said to be a "non-newtonian fluid" which means it has variable viscosity. Oobleck flows and behaves like a liquid under gentle pressure (it conforms to the shape of a cup and can be stirred slowly) but under more intense pressure it becomes rigid, like a solid. Quicksand is another example.

Oobleck also made an appearance on network TV recently. On Big Bang Theory, the guys had wrapped a stereo speaker in plastic wrap and set a puddle of oobleck on it. There are lots of videos of this on YouTube, but they use a steady tone instead of music like the TV show had. So turn your volume down.

There's lots more fun with non-newtonian fluids on YouTube (including a bunch of British science videos featuring Richard Hammond from Top Gear - who knew!), but this one is probably the best:

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