Today I taught two classes this morning. After lunch I went back to Wenona School for another meeting with the Science Club students there. We continued working on the pinhole cameras we built a few weeks ago. At the time we ran out of tracing paper and made two of the boxes with tissue paper instead, which is both more fragile and also less translucent, so it was definitely not as good. Today we had more tracing paper, which we used to replace the tissue paper. We also trimmed one of the other boxes more neatly and stretch the tracing paper more flat across the opening.
After that, I helped start setting up a schlieren photography setup. We mounted a concave mirror on a retort stand with a couple of clamps, and then used a pinhole taped to a xenon bulb light to get a bright beam of light, and found the focal distance of the mirror and focused the light onto a screen next to the light source. For the next step we needed a knife edge and a camera, but time was running out and the lab assistants helping us couldn’t get them in time. So we left the remainder of the setup for next time.
Well be taking a two-week break for the end of term holidays, and then when we come back in three weeks hopefully we can finish it off and take some cool photos of things like the turbulence above a candle flame.
On the way back home I picked up Scully from my wife’s work, and then I had three more classes this evening. A pretty full day!