We had exchange students from Takatori, Japan today in class. It was an honor to show the students what my class was like. I hope they had fun.
I planned the first part of the lesson to be something we could experience, so, even if they didn't understand all the words, they could get something out of it. I broke out the polarizers. We looked at the many things through a polarizer—the sky, glare, our old calculators, even the older iPhones. We saw some real differences. Then, with two polarizers, we came up with an idea of why polarizers give us evidence that light is a transverse wave.
Then we used this simulation we can use on a Chromebook to watch how waves deal with openings. We definitely saw a pattern with small versus large openings, so we ended up talking about diffraction.