The Wikipedia article contains a helpful table [1], which classifies optical illusions. One kind are "physical" illusions, like rainbows or distortions (think s

The Wikipedia article contains a helpful table [1], which classifies optical illusions. One kind are "physical" illusions, like rainbows or distortions (think stick in water). I think the hovering ship is of that kind. Other kinds include "physiological" or "cognitive", which are tricking your brain. [1] https://en.wikipedia.org/wiki/Optical_illusion#/media/File:Gregory_categorization_of_illusions_1991.png https://en.wikipedia.org/wiki/Optical_illusion#/media/File:G...