Sunday, May 4, 2008

Sunday Evening Science

All right, boys and girls, it's time to learn something new. First, go into your mom's kitchen and get the box of corn starch. Go ahead, I'll wait. Oh, and while you're in there, get an empty bowl and a glass of warm water. All right.

I'm waiting.

You got it? Good. Now, pour a bit of the corn starch in the empty bowl and then add the water, a little bit at a time, stirring it as you go. Do this until, when you stir slowly, the liquid moves easily, but when you try to stir it quickly, it seems like the liquid is hard to move through. Got it?

Congratulations. You've now made yourself a Non-Newtonian Fluid. A non-Newtonian fluid is a fluid in which the viscosity changes with the applied shear stress. As a result, non-Newtonian fluids may not have a well-defined viscosity. What does that mean? Stir it slowly and it's watery, stir it quickly, and it's thick.

But that's not very fun, is it. Or is it?

These men are playing with a whole pool of non-newtonian fluid.

Here's something to try. Scoop some of the fluid up and really quickly, try to make a ball. Once you've got the ball, let it sit on your hand. What happens? As soon as you let it rest, it oozes back down into fluid form, doesn't it?

Wanna make icky slime monsters? Take your father's or your brother's amp (or speaker, it would work just as well) and lay it down on the floor. Cover it with plastic wrap. Then, pour your non-newtonian fluid on it. Turn that sucker on. High. You get to watch your own awesome slime monster, plus you have the added bonus of annoying everyone in your house, and maybe your neighbors as well.

Now, wasn't learning fun?