Some New and Some Classic Explorations from the Exploratorium

by Paul Doherty


The Exploratorium Website, over ten thousand pages of ideas:

Paul Doherty's Website, hundreds of pages of scientific explorations:

Iron Science Teacher, dozens of hour-long programs of science teaching ideas.

Books: Here's my latest science exploration book, written with Don Rathjen.

The Sequel to the Snackbook, "Square Wheels" 30 new science explorations.


Explorations presented at my lecture.

Falling Dominos, exponential growth., A falling domino can knock over a larger domino.

Floating in copper, fly one magnet in air with the help of eddy currents.

Guided rolling magnets. A disk magnet will be guided down the center of a magnetic track by eddy currents.

*Magnetic accelerator. Steel balls attracted to magnets will accelerate down an aluminum track.

*Magnet collisions on a pencil., Donut magnets exhibit elastic collisions when held on a pencil with a steel eraser band.

*Barkhausen effect. An audio amplifier and an iron core coil can be used to listen to magnetic domains.

pick-up coil metal detector feedback amp. The frequency of feedback in an audio system is changed by the presence of metal.

Magnetic cassette tape (In Square Wheels), Make the worlds cheapest digital tape recorder.

*Magnetic oscillator. Two magnets which attract face-to-face, repel when moved to the side, and so we need fields to understand their mutual forces.

*Repel a grape (In Square Wheels) Use a neodymium magnet to repel a grape full of diamagnetic sugar water.

Ferrofluid. You can make your own ferrofluid by scraping magnetic particles off a cheap VCR tape and then placing them in oil.

*Coins floating on water Aluminum coins will float on the surface tension of water, if you use a plastic fork.

Drop a slinky, Hold a slinky by its top, let it stretch down, when released, the top will accelerate faster than g.

Ringing Aluminum rod, Tempered aluminum has a high Q, it will ring for a minute when struck by a hammer.

*Breathe sulfur hexafluoride. The speed of sound in sulfur hexafluoride is lower than the speed of sound in air. This will lower the resonances of your voice.

*Whirly Corrugated tubes can be made to sing when air blows through them. (Thanks to Frank Crawford)

Demos on the tables.

spinning cylinder, (In Square Wheels) A spinning cylinder of PVC shows surprising patterns.

Soap film in a can, (In Square Wheels) Dip the open mouth of a black film can into soapy water, hold it over white paper and observe interference colors.

R G B IR LED's and voltage, The voltage needed to light an LED is a proportional of its frequency.

Seeing IR, A digital camera is sensitive to near IR.

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Scientific Explorations with Paul Doherty

© 2002

23 October 2002