I’ve gotten behind on posting (again). Holidays and illness have hit us. I will get something up soon, I promise.
In the meantime, here’s a quick plug for Diffraction Grating Glasses. I ordered a batch of these for the kids this year. Put them on and look at a light source — candles, tree lights, lamps, headlights — and see rainbows as the glasses separate light into its spectral components. You can also get them from Edmund Scientific. This page from ScienceHouse.org recommends a simple home experiment with kids as young as first grade. So besides having fun with them to see rainbows, you can use them to “look at different light sources such as a black light, an infrared light, a full spectrum white light and a light for a photo lab and get them to make a drawing of each spectrum in their science journals and compare the spectra.” If you don’t see this post in time to acquire some for Christmas, you can also use them for watching fireworks, conducting light experiments, or giving them out at Halloween, so really, it’s never too late to get them. Enjoy!