Epistemology
The Necker cube is used in epistemology (the study of knowledge) and provides a counter-attack against naïve realism. Naïve realism (also known as direct or common-sense realism) states that the way we perceive the world is the way the world actually is. The Necker cube seems to disprove this claim because we see one or the other of two cubes, but really, there is no cube there at all: only a two-dimensional drawing of twelve lines. We see something which is not really there, thus (allegedly) disproving naïve realism. This criticism of naïve realism supports representative realism.
A rotating Necker cube was used to demonstrate that the human visual system can recruit new visual cues that affect the way things look.
A doctored photograph purporting to be of an impossible cube was published in the June 1966 issue of Scientific American, where it was called a "Freemish Crate".
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