I have always wondered if something that I had seen in simulations and animations could be made as a physical model that students could interact with and investigate.
This model sweeps out a pattern made by two coherent waves as they “interact” with each other with constructive and destructive interference. While the full amplification of constructive interference isn't completely represented with this design, it is still clear where the the “bright and dark spots" would appear as a result of the interactions.
Printing notes:
The author marked this model as their own original creation.