Undecidable Monument

Scan of Hayward’s drawing of a blivet in the form of an “undecidable monument”

A blivet, also known as an “impossible fork,” is an optical illusion and an impossible object. It appears to have three cylindrical prongs at one end which then mysteriously transform into two rectangular prongs at the other end. Often, upon first glance, the blivet looks entirely possible, but upon closer inspection quickly becomes undecipherable. Other impossible figures include the impossible cube or Penrose triangle, which also initially appear to be two dimensional representations of real objects. On closer inspection, however, such figures are found to have parts drawn from incompatible perspectives. The blivet is often used to amuse, entertain, and fascinate the viewer, revealing humankind’s endless fascination with the creative and unusual.