First day of the new school year starts on Monday, and I'm stoked.

I've put together new demos over the summer to measure the Hall Effect in class, as well as creating a rainbow from a "single rain drop."

The Hall effect is subtle and difficult to measure, and I had to purchase a 20 A power source to be able to show the tiny effect. After much failure trying to tease out a measurement of a few nano Volts, the increased current from the new power supply gave me a signal in the micro Volt range, which is much easier to measure in a classroom.

The single rain drop is not rain... not even water, but the physics is effectively the same. I have a spherical beaker filled with Glycerol. These 2 (glass and Glycerol) have the same index of refraction, so the fact that it's a liquid in a solid container is not an issue. There is no surface where the index of refraction changes except between the glass and the air. It's really more like making a rainbow from a glass bead, but the differences are inconsequential aside from the angular size of the rainbow.


I've got concert tickets to see Walk Off the Earth in November. They're probably the only actively touring band that I'd want to see live, and the fact that they're coming through St Louis to play a show on a Saturday night is just too much awesome for me to pass up. I know that FTR tends to favor electronic or heavy metal music, so I don't expect their sound to appeal to too many here, but I'm perfectly excited to tell everyone I know that my favorite band is coming to town.

Their latest music video