This blivet is reminiscent of an M.C. Escher print—it portrays two impossible perspectives at once, creating a 'lost' layer between the top two rods, and an impossible extra, vanishing rod in between the bottom two.

The blivet is an undecipherable figure, 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. Download high resolution version (1000x477, 12 KB)This figure is the simplified outline of a drawing by Roger Hayward from an article on Blivets: Research and Development published in The Worm Runners Digest (December 1968) and reproduced in Martin Gardners Mathematical Circus (Pelican Books 1981, ISBN 0 14... Download high resolution version (1000x477, 12 KB)This figure is the simplified outline of a drawing by Roger Hayward from an article on Blivets: Research and Development published in The Worm Runners Digest (December 1968) and reproduced in Martin Gardners Mathematical Circus (Pelican Books 1981, ISBN 0 14... Hand with Reflecting Sphere (Self-Portrait in Spherical Mirror), 1935. ... Perspective when used in the context of vision and visual perception refers to the way in which objects appear to the eye based on their spatial attributes or dimension and the position of the eye relative to the objects. ... An optical illusion characterized by visually perceived images that, at least in common sense terms, are deceptive or misleading. ... Two famous undecidable figures, the Penrose triangle and devils pitchfork. ...

Blivet has numerous other meanings, explained below.

Usage in Military Circles

In traditional U.S. Army slang dating back to the Second World War, a blivet was defined as "ten pounds of manure in a five pound bag," (a proverbial description of anything egregiously ugly or unmanageable); it was applied to an unmanageable situation, a crucial but substandard or damaged tool, or a self-important person. In Cormac McCarthy's All the Pretty Horses, Rawlins defines a blivet as "10 pounds of shit in a 5 pound sack." During the Vietnam conflict, a heavy rubber bladder in which aircraft fuel or POL (petroleum, oil. lubricants) was transported was known as a blivet, as was anything which, once unpacked, could not be replaced in its container. For the musician Cormac McCarthy, see Cormac McCarthy (musician). ...

In various United States Air Force communities (eg Strategic Air Command), blivet may have referred to what are euphemistically called "Special Weapons" whose presence are officially neither confirmed nor denied. Usage apparently derived from the original cavalry definition. The United States Air Force (or USAF) is the aerospace branch of the United States armed forces and one of the seven uniformed services. ... SAC shield The Strategic Air Command or SAC (1946-1992) was the branch of the United States Air Force in charge of Americas bomber-based and ballistic missile-based strategic nuclear arsenal, as well as the infrastructure necessary to support their operations (such as tanker aircraft to fuel the...

In some areas of the U.S., it refers to a juvenile prank, clearly connected with the original military usage: a sack full of excrement is ignited on the victim's porch, while the pranksters ring the doorbell and run. The victim attempts to put the flames out by stamping on the bag. This may also be related to the term's claimed use as military slang for a land-mine, not well-documented.

Uses in Technology Communities

Among computer programmers, a blivet refers to any embarrassing glitch that pops up during a customer demonstration. Among computer security specialists, it can refer to a denial-of-service attack performed by monopolizing limited resources that have no access controls (for example, shared spool space on a multi-user system). There are other meanings in other technical cultures; among experimental physicists and hardware engineers it may designate any random object of unknown purpose (similar to hackers' use of frob). The term Frob has typically been used to refer to any small device or object (usually hand-sized) which can be manipulated, or frobbed. ...

"Placeholder" Usage

The word blivet is sometimes used as a cadigan. In Economics, the term may be used (like "widget") for some hypothetical product. A placeholder name is used to refer to an object whose name is either irrelevant or unknown in the context which it is being discussed. ... Buyers bargain for good prices while sellers put forth their best front in Chichicastenango Market, Guatemala. ... Widget is a general-purpose term, or placeholder name, for any unspecified device, including those that have not yet been invented. ...

Reference to Paradoxical Figure

In yet another usage, illustrated above, the blivet is an undecipherable figure. It was shown on the March 1965 cover of Mad magazine (who dubbed it the poiuyt, derived from the last 6 letters on the top row of a typewriter keyboard, right to left), and has appeared numerous times since then. An anonymously-contributed version described as a hole location gauge was printed in the June 1964 issue of Analog Science Fact/Science Fiction, with the comment that "this outrageous piece of draftsmanship evidently escaped from the Finagle & Diddle Engineering Works". Harvey Kurtzmans cover for the first issue of the comic book Mad Mad is an American humor magazine founded by publisher William Gaines and editor Harvey Kurtzman in 1952. ... Mechanical desktop typewriters, such as this Underwood Five, were long time standards of government agencies, newsrooms, and sales offices. ... Astounding Stories was a seminal science fiction magazine founded in 1930. ...

The artist M.C. Escher was famous for utilizing this object in many of his drawings, lithographs, woodcuts and many such other media. Hand with Reflecting Sphere (Self-Portrait in Spherical Mirror), 1935. ...

Alternative names

• Devil's pitchfork
• Devil's tuning fork
• Hole location gauge
• Mark III blivet
• Poiuyt
• Rectabular excrusion bracket
• Three-legged widget
• Three pronged blivet
• Trichotometric indicator support
• Two-pronged trident
• Widget

Widget is a general-purpose term, or placeholder name, for any unspecified device, including those that have not yet been invented. ...

External links

Look up Blivet in
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Wikimedia Commons has media related to:

Optical illusion

• photograph of fuel blivets
• USAF B-53 "Blivet"
• An Impossible Fork at cut-the-knot
• Impossible figure