Blivet

This blivet portrays two irreconcilable perspectives at once: descending from the top are two bars with rectangular cross-section, while ascending from the bottom are three cylindrical rods.

With backgrounds to enhance the illusion

Hayward's "undecidable monument"

A blivet, also known as a poiuyt, devil's fork or widget, 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.^{[original research?]}

Paradoxical graphic figure

In its most common usage, the word "blivet" refers to an indecipherable figure, illustrated above.^{[citation needed]} It appeared on the March 1965 cover ^[1] of Mad magazine, where it was dubbed the "Three-Pronged Poiuyt" (the last six letters on the top row of many Latin-script typewriter keyboards, 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 Fiction and Fact, with the comment that "this outrageous piece of draftsmanship evidently escaped from the Finagle & Diddle Engineering Works" (although something else called a "hole location gauge" had already been patented in 1961 ^[2])

The graphic artist M. C. Escher used these types of figures as the basis for impossible three-dimensional compositions in many of his woodcut prints.

In December 1968 American optical designer and artist Roger Hayward wrote "Blivets: Research and Development" for The Worm Runner's Digest in which he presented interpretations of the blivet.^[3]

Other meanings of word

Military usage

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 bag". During the Vietnam War, a heavy rubber bladder in which aviation fuel or POL (petroleum, oil, and lubricants) was transported was known as a blivet, as was anything which, once unpacked, could not be replaced in its container. The usage of blivet for a fuel container is still current.

In various United States Air Force communities (e.g. 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.

In the United States Unmanned Aerial Systems community (specifically Shadow UAS) a blivet is a tool used to test the system's launcher to ensure proper functionality. The Shadow system's blivet weighs approximately 375 lbs - the same as a fully fueled Shadow 200 Tactical Unmanned Aerial Vehicle (RQ-7B). It is a green hexagonally shaped piece of iron with four mounting points.

In Naval Aviation, a blivet is the common term for an external baggage container carried on a tactical jet.

Technological usage

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).

Early versions of Adobe Photoshop used a blivet on the plugin icon.

An early version of the Microsoft logo had the letter "o" formed with several horizontal lines and was internally known as the blibbet.^[4]

"Placeholder" usage

The word blivet is sometimes used as a cadigan. In economics, the term may be used (like "widget") for some hypothetical product.

Other

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.

Alternative names

• Ambiguous Trident
• Devil's Pitchfork
• Devil's Tuning Fork
• Mark III Blivet
• Three-Legged Blivet
• Three-Pronged Poiuyt
• Trichotometric Indicator Support
• Three-Forked, One Slot widget (Games magazine)
• Veeblefetzer

External links

• Article "Impossible Fork" at MathWorld

Notes

1. ^ "Doug Gilford's Mad Cover Site - Mad #93". Madcoversite.com. http://madcoversite.com/mad093.html. Retrieved 2010-10-22. 
2. ^ "Hole location gauge - Patent 2998656". Freepatentsonline.com. 1961-09-05. http://www.freepatentsonline.com/2998656.html. Retrieved 2010-10-22. 
3. ^ Gardner, Martin (1981). Mathematical Circus. Pelican Books. p. 5. 
4. ^ "NPR Media Player". Npr.org. http://www.npr.org/templates/player/mediaPlayer.html?action=1&t=4&islist=true&id=35&d=11-08-2008. Retrieved 2010-10-22.