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Impossible objects

Explore impossible objects and figures: Penrose triangle, endless stairs, impossible cubes and more. Trace the geometry and discover how the drawings work. Convincing parts that cannot fit together.

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The collection

A rectangular loop of steps that appears to ascend continuously.

Penrose stairs

Oscar Reutersvärd; independently Lionel & Roger Penrose

A staircase that climbs forever and gets nowhere.

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A pale blue drawing of connected corners whose locally plausible edges cannot form a consistent solid.

Impossible Corners

Oscar Reutersvärd (1915 - 2002), Swedish graphic artist

You should experience a sense of perceptual confusion as you note the paradoxical nature of the corners.

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Three rectangular beams joined in an apparently solid triangular loop.

Penrose triangle

Oscar Reutersvärd; independently Lionel & Roger Penrose

Three convincing corners. One impossible connection.

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Andrus’s nuts and bolts — An arrangement of real nuts and bolts looks impossible from its chosen view.

Andrus’s nuts and bolts

Jerry Andrus; photograph by Sgerbic

An arrangement of real nuts and bolts looks impossible from its chosen view.

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Impossible chair — A digitally altered chair gives its supports contradictory connections.

Impossible chair

TipFox

A digitally altered chair gives its supports contradictory connections.

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Impossible hexagon — A six-sided beam loop carries impossible depth around its perimeter.

Impossible hexagon

Original uploader was Trilink at en.wikipedia

A six-sided beam loop carries impossible depth around its perimeter.

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Impossible octagon — Eight sides make a deceptively convincing impossible loop.

Impossible octagon

Trilink at English Wikipedia

Eight sides make a deceptively convincing impossible loop.

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An animated red-and-green ring with striped surfaces whose apparent depth can reverse.Moving image

Ambiguous Ring

Donald E. Simanek

You should experience a sense of perceptual confusion as you note the paradoxical nature of the depicted ring.

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Axonometric paradox — An axonometric structure resists a single depth interpretation.

Axonometric paradox

Nevit Dilmen

An axonometric structure resists a single depth interpretation.

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Three cylindrical prongs apparently connected to two rectangular supports.

Impossible trident

Original creator uncertain; reported by D. H. Schuster

Three prongs quietly become two supports.

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Frequently asked questions

What is an impossible object?

An impossible object is a drawing whose parts suggest familiar three-dimensional shapes but cannot all connect as they appear to. The contradiction becomes clearer when you trace the whole structure.

Can a Penrose triangle be built?

It cannot exist as the ordinary solid the drawing suggests. A specially arranged model can create the appearance from one viewpoint, but its actual structure differs from the pictured object.

How do the Penrose stairs work?

The drawing joins plausible stair segments into an apparent loop that continually rises or falls. In ordinary space, a closed circuit cannot gain height at every step and return to its starting level.

Enlarged image from the selected gallery entry