An arrow is a graphical
symbol
A symbol is a mark, sign, or word that indicates, signifies, or is understood as representing an idea, object, or relationship. Symbols allow people to go beyond what is known or seen by creating linkages between otherwise very different conc ...
, such as ← or →, or a
pictogram
A pictogram, also called a pictogramme, pictograph, or simply picto, and in computer usage an icon, is a graphic symbol that conveys its meaning through its pictorial resemblance to a physical object. Pictographs are often used in writing and ...
, used to point or indicate direction. In its simplest form, an arrow is a triangle,
chevron
Chevron (often relating to V-shaped patterns) may refer to:
Science and technology
* Chevron (aerospace), sawtooth patterns on some jet engines
* Chevron (anatomy), a bone
* '' Eulithis testata'', a moth
* Chevron (geology), a fold in rock la ...
, or
concave kite, usually
affixed to a
line segment
In geometry, a line segment is a part of a straight line that is bounded by two distinct end points, and contains every point on the line that is between its endpoints. The length of a line segment is given by the Euclidean distance between i ...
or
rectangle
In Euclidean plane geometry, a rectangle is a quadrilateral with four right angles. It can also be defined as: an equiangular quadrilateral, since equiangular means that all of its angles are equal (360°/4 = 90°); or a parallelogram contain ...
,
and in more complex forms a representation of an actual
arrow
An arrow is a fin-stabilized projectile launched by a bow. A typical arrow usually consists of a long, stiff, straight shaft with a weighty (and usually sharp and pointed) arrowhead attached to the front end, multiple fin-like stabilizers ...
(e.g. ➵ U+27B5). The direction indicated by an arrow is the one along the length of the line or rectangle toward the single pointed end.
History
An older (medieval) convention is the
manicule
The manicule, , is a typographic mark with the appearance of a hand with its index finger extending in a pointing gesture. Originally used for handwritten marginal notes, it later came to be used in printed works to draw the reader's attention ...
(pointing hand, 👈).
Pedro Reinel
Pedro Reinel (fl. 1485 – 1540) was a Portuguese cartographer. Between 1485 and 1519 Reinel served three Portuguese kings: João II, Manuel I and João III. He and his son, Jorge Reinel, were among the most renowned cartographers of their era ...
in c. 1504 first used the
fleur-de-lis
The fleur-de-lis, also spelled fleur-de-lys (plural ''fleurs-de-lis'' or ''fleurs-de-lys''), is a lily (in French, and mean 'flower' and 'lily' respectively) that is used as a decorative design or symbol.
The fleur-de-lis has been used in the ...
as indicating north in a
compass rose
A compass rose, sometimes called a wind rose, rose of the winds or compass star, is a figure on a compass, map, nautical chart, or monument used to display the orientation of the cardinal directions (north, east, south, and west) and thei ...
;
the convention of marking the eastern direction with a cross is older (medieval).
Use of the arrow symbol does not appear to pre-date the 18th century. An early arrow symbol is found in an illustration of
Bernard Forest de Bélidor
Bernard Forest de Bélidor (1698, Catalonia, Spain – 8 September 1761, Paris, France) was a French engineer, significant to the development of the science of hydraulics and ballistics.
He was the son of Jean Baptiste Foret de Belidor, an offi ...
's treatise ''L'architecture hydraulique'', printed in France in 1737. The arrow is here used to illustrate the direction of the flow of water and of the water wheel's rotation. At about the same time, arrow symbols were used to indicate the flow of rivers in maps.
[E. H. Gombrich, "Pictorial Instructions" in: H. Barlow et al. (eds.), ''Images and understanding'', Cambridge University Press (1990).]
A trend toward abstraction, in which the arrow's
fletching is removed, can be observed in the mid-to-late 19th century. The arrow can be seen in the work of
Paul Klee
Paul Klee (; 18 December 1879 – 29 June 1940) was a Swiss-born German artist. His highly individual style was influenced by movements in art that included expressionism, cubism, and surrealism. Klee was a natural draftsman who experimented ...
. In a further abstraction of the symbol, John Richard Green's ''
A Short History of the English People
''A Short History of the English People'' is a book written by English historian John Richard Green. Published in 1874, "it is a history, not of English Kings or English Conquests, but of the English People."
Background and reception
Green bega ...
'' of 1874 contained maps by cartographer Emil Reich, which indicated army movements by curved lines, with solid triangular arrowheads placed intermittently along the lines.
[History of the Arrow]
American Printing History Society (2015).
Use of arrow symbols in
mathematical notation
Mathematical notation consists of using symbols for representing operations, unspecified numbers, relations and any other mathematical objects, and assembling them into expressions and formulas. Mathematical notation is widely used in mathem ...
is still younger and develops in the first half of the 20th century.
David Hilbert
David Hilbert (; ; 23 January 1862 – 14 February 1943) was a German mathematician, one of the most influential mathematicians of the 19th and early 20th centuries. Hilbert discovered and developed a broad range of fundamental ideas in many ...
in 1922 introduced the arrow symbol representing
logical implication.
The double-headed arrow representing
logical equivalence
In logic and mathematics, statements p and q are said to be logically equivalent if they have the same truth value in every model. The logical equivalence of p and q is sometimes expressed as p \equiv q, p :: q, \textsfpq, or p \iff q, depending o ...
was introduced by
Albrecht Becker in ''Die Aristotelische Theorie der Möglichkeitsschlüsse'', Berlin, 1933.
[
]
Usage
Arrows are universally recognised for indicating directions. They are widely used on signage
Signage is the design or use of signs and symbols to communicate a message. A signage also means signs ''collectively'' or being considered as a group. The term ''signage'' is documented to have been popularized in 1975 to 1980.
Signs are any ...
and for wayfinding
Wayfinding (or way-finding) encompasses all of the ways in which people (and animals) orient themselves in physical space and navigate from place to place.
Wayfinding software is a self-service computer program that helps users to find a location, ...
, and are often used in road surface markings.
Upward arrows are often used to indicate an increase in a numerical value, and downward arrows indicate a decrease.
In mathematical logic
Mathematical logic is the study of formal logic within mathematics. Major subareas include model theory, proof theory, set theory, and recursion theory. Research in mathematical logic commonly addresses the mathematical properties of forma ...
, a right-facing arrow indicates material conditional
The material conditional (also known as material implication) is an operation commonly used in logic. When the conditional symbol \rightarrow is interpreted as material implication, a formula P \rightarrow Q is true unless P is true and Q i ...
, and a left-right (bidirectional) arrow indicates if and only if
In logic and related fields such as mathematics and philosophy, "if and only if" (shortened as "iff") is a biconditional logical connective between statements, where either both statements are true or both are false.
The connective is bic ...
, an upwards arrow indicates the NAND operator (negation of conjunction), an downwards arrow indicates the NOR operator (negation of disjunction).
Unicode
In Unicode
Unicode, formally The Unicode Standard,The formal version reference is is an information technology standard for the consistent encoding, representation, and handling of text expressed in most of the world's writing systems. The standard, ...
, the block Arrows occupies the hexadecimal
In mathematics and computing, the hexadecimal (also base-16 or simply hex) numeral system is a positional numeral system that represents numbers using a radix (base) of 16. Unlike the decimal system representing numbers using 10 symbols, he ...
range U+2190–U+21FF, as described below.
By block
Additional arrows can be found in the Combining Diacritical Marks
Combining Diacritical Marks is a Unicode block containing the most common combining characters. It also contains the character " Combining Grapheme Joiner", which prevents canonical reordering of combining characters, and despite the name, actu ...
, Combining Diacritical Marks Extended
Combining Diacritical Marks Extended is a Unicode block containing diacritical marks used in German dialectology (Teuthonista
Teuthonista is a phonetic transcription system used predominantly for the transcription of (High) German dialects. I ...
, Combining Diacritical Marks for Symbols, Halfwidth and Fullwidth Forms
In CJK (Chinese, Japanese and Korean) computing, graphic characters are traditionally classed into fullwidth (in Taiwan and Hong Kong: 全形; in CJK: 全角) and halfwidth (in Taiwan and Hong Kong: 半形; in CJK: 半角) characters. Unlike ...
, Miscellaneous Mathematical Symbols-B
Miscellaneous Mathematical Symbols-B is a Unicode block containing miscellaneous mathematical symbols, including brackets, angles, and circle symbols.
Block
Some of these symbols are used in Z notation. Specifically
*
*
*
*
*
*
The last two ...
, Miscellaneous Symbols and Pictographs, Miscellaneous Technical, Modifier Tone Letters and Spacing Modifier Letters Unicode block
A Unicode block is one of several contiguous ranges of numeric character codes ( code points) of the Unicode character set that are defined by the Unicode Consortium for administrative and documentation purposes. Typically, proposals such as the ...
s.
See also
* Dingbat
In typography, a dingbat (sometimes more formally known as a printer's ornament or printer's character) is an ornament, specifically, a glyph used in typesetting, often employed to create box frames, (similar to box-drawing characters) or as ...
* Box Drawing (Unicode Block)
* Block Elements (Unicode Block)
* Geometric Shapes (Unicode Block)
* Box-drawing character
References
*J. R. Finkel,
"History of the Arrow"
''Up Down Left Right'' (2011)
External links
Semantics of Simple Arrow Diagrams
Emojipedia
Complete list of arrow symbols
{{Mathematical symbols notation language
Logic symbols
Pictograms
Unicode