I’ve been kept busy trying to keep my three year old busy. A fun and educational project that I’ve tried to engage him with is understanding magnetism. To do this, I designed a simple experiment shown in the video below. This experiment was made possible with the huge magnet attached to a book I read when I was younger, the Exploratorium’s “Explorabook”. I brought this book out for my son to look over recently, and he enjoyed working (more just watching, but that’s kind of the point at his current age) with me. The nice thing about magnetism and some of the concepts explored in the Explorabook are that they are hands-on and can be explored in a few minutes time, just within a typical three year olds’ attention span.
Magnetism from Phil Wu on Vimeo.
The basic idea is to show that the paper clip is attracted to the magnet within an “attraction distance” (next time we work on this I’ll put a measuring ruler in the background). The clip won’t just get sucked up to the magnet because of tape securing a string attached to the clip. Pulling on the string, and lowering the clip below this magical distance causes the paper clip to fall directly onto the table. Although we can’t really see why the paper clip is attracted to the magnet, this experiment makes clear that something, a force, is at work. Changing the paper clip for a piece of paper or even a strip of tape won’t have the same observable effects. So there’s something additionally “special” about the paper clip (it’s more metallic than the paper or tape).
Many of these concepts can be re-visited time and again a few years from now, but I thought it important to point out even the slightly more wonkish aspects mentioned above. When my son has a better grasp of mathematics and length scales, I’ll tell him the force is proportional to the inverse distance cubed (I’m thinking the Biot-Savart calculation).
References:
1. Cassidy, John. (1991) Explorabook: A Kids’ Science Museum in a Book, Palo Alto, Klutz Press.
2. https://vimeo.com/331669743
3. https://vimeo.com/user97631083
4. https://vimeo.com/