Four-dimensional space – Geometric space with four dimensions

Mathematics and art – Relationship between mathematics and art

Möbius strip – Two-dimensional surface with only one side and only one edge

Necker cube – Form of perceptual phenomena

Non-Euclidean geometry – Two geometries based on axioms closely related to those specifying Euclidean geometry

Paradox – Statement that apparently contradicts itself

Puzzle – Problem or enigma that tests the ingenuity of the solver

strange loop – Cyclic structure that goes through several levels in a hierarchical system.

surrealism – International cultural movement started in 1917

Tesseract – Four-dimensional analogue of the cube

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