Optical Illusions and Visual Phenomena
What a fantastic page.  When I was teaching (music technology) in schools, I used to use optical illusions like these (and the illustration of the blind spot, which many of the kids hadn&#x27;t seen before!) to illustrate that our senses are <i>not</i> calibrated, scientific instruments, but that we experience the world in a somewhat different manner to reality.<p>After seeing things like this, the pupils were a lot more open to the idea that their hearing may not be completely accurate, and that the harmonic series in a single note (which we hear all as one tone) could be perceived by another intelligent species as a series of discrete sounds.  They also got how lossy audio encoding could throw away masked sounds because our hearing can also be fooled.  It was always a great moment seeing them realise that a door had opened to a new understanding of how they navigated the world, and that their assumptions were incorrect (for some of them, of course!)