Even if you don’t have some, you can see it in action with our Thinking Putty video:
Putty is a Non-Newtonian substance, which means that it doesn’t follow the theory of viscosity that Newton observed. Viscosity is the “thickness” of a liquid, or its resistance to flow. (Honey, for example, has a much higher viscosity than water.) Thinking Putty, while sometimes having properties of a high-viscosity liquid, also has certain properties of a solid. Like a liquid, it won’t hold its shape, although because of its high viscosity, it moves very slowly. Unlike most liquids, however, Thinking Putty changes its behavior based on the amount of force applied. If you pull it gently, it will stretch; if you pull it forcefully, it will tear. If you push your finger in gently it will sink deep into the putty, but if you jab it hard your finger will bounce right off. When you apply the ultimate force—hitting it with a hammer—it acts exactly like a solid and shatters as though it were ceramic. (But then you can pick up the pieces and stretch and smash them like putty again!)
Stretching, Tearing, and Popping Tricks:
One of the most fun things to do with putty is just to stretch, twist, squish, and mold it into shapes. While you’re at it, you can make a little noise.
1. Stretch your putty out into a thin sheet. Fold it over once, then again the opposite way. Keep folding until you can’t fold any more. When its all folded up, squeeze it to hear it pop! When you stretched and folded, you trapped air bubbles in the putty. Experiment with ways to get even bigger air bubbles trapped to make more noise.
2. You’ve seen how putty stretches out when you pull it gently. This makes it hard to break off a piece; it just keeps stretching out. Because it’s a Non-Newtonian substance, though, Thinking Putty will act like a solid if you apply enough force. Pinch the putty at an edge and then quickly tear it across, just like you would tear a piece of paper. If you use enough force, it will tear into two pieces cleanly, instead of stretching.
Changing Color:
Some Thinking Putty is thermo-chromatic, meaning that it changes color with changes in temperature! Just playing with the putty in your hands will warm it up enough to change colors, but you can also use a hairdryer to change its color in quick, dramatic fashion. Then use something cold, like ice or compressed air, to “draw” on your warm putty. If you just stick a piece of ice onto the putty, you’ll see the cold color “glow” through the ice cube.
Bouncing & Smashing Tricks:
1. Roll your putty into a ball and drop it on the counter or floor—it will bounce like a rubber ball!
2. It bounces, but it also shatters! You may want to do this part outside so you don’t make a mess. Your putty will get a little dirty, so just use a small part of it. Put a ball of putty on a concrete or cement surface, hit it forcefully with a hammer, and watch it shatter. Wear safety glasses to protect your eyes from flying pieces of putty.
These are just a few activities with Thinking Putty – experiment to find more fun things to do with it! You can also get magnetic varieties.
