Science toys you can make with your kids

Whole Earth, Winter, 2002

The coolest source of educational science demonstrations I've encountered is this very book-like website written and run by Simon Field. Field has thirty nifty toys and gadgets that can be made quickly, cheaply and will amaze adults as well as kids. This is the only place I've seen that tells you how to make a magnetic linear accelerator, also known as a Gauss Rifle--it uses magnetism to shoot tiny steel balls. The secret to Field's method is that his demos are very small, requiring small amounts of material, energy, or money. Most of his experiments can be assembled--even if you buy the stuff--for a few dollars, and can fit in your palm. His instructions and visuals are simply the best I've seen in any how-to-book. Most wonderful of all, it's entirely up on the web for free. Hats off to you, Mr. Field. (He does sell kits, and parts, which may help pay for his server, I guess.)--KK

Building the Film Can Cannon

This toy was an instant favorite from the moment its first loud Bang! and flash of orange flame launched the little black film can up to bounce off our 26 foot ceiling It has several names: the Piezo-Popper, the Binaca Bomb, the Photo-Flash--you will probably come up with more.

The toy is very easy to make, going together in about 15 minutes, at a cost of two or three dollars if all the parts are purchased new, or free if you don't throw away certain common household items.

The fuel for the cannon can be found around the house. We have run ours on perfume, hair spray, and (our favorite) Wintergreen Binaca mouth freshener.

The cannon is very simple. A pair of wires are pushed through a slit made in the top of a plastic 25 millimeter film can. The other ends of the wires are soldered to the igniter element from an electronic cigarette or fireplace lighter. I chose to mount these elements on a block of wood, but this is optional if you're in a hurry.

The fire the cannon, you spray the fuel (one squid of perfume or Binaca, or a very short squid of hair spray) into the plastic film can, push the can down on the lid, and press the igniter.

With a loud Bang! and a flash of orange flame, the little can goes sailing into the air. With some practice in getting just the right amount of fuel in the can, it will go as high as 30 feet straight up. If too much or too little fuel is used, it will either not ignite at all, or it will not go very high.

Science Toys You Can Make with Your Kids www.scitoys.com

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