Degree symbol

From Wikipedia, the free encyclopedia

The degree symbol (°, Unicode: U+00B0, HTML: °) is a typographical symbol, or glyph, that is used to represent degrees of arc (see Geographic coordinate system ) or temperature.

Especially in the biological and medical fields, 1°, 2°, and 3° are common abbreviations for primary, secondary, and tertiary (but this is actually the "masculine ordinal indicator" not a degree symbol). In medical shorthand, the degree symbol is also used to denote hours, for instance q4° or q4° meaning "every four hours."

Since at least the age of desktop publishing, personal computers have been able to produce the degree symbol. See "Input" below for details.

[edit] Typography

The degree symbol was originally an ancient symbol representing the Sun.^{[citation needed]}

[edit] Degrees of arc

In the case of degrees of arc, the degree symbol follows the number without intervening space.

[edit] Temperatures

[edit] Degrees Celsius and Fahrenheit

In contrast to expressing degrees of arc, in the case of degrees of temperature, several scientific and engineering standards bodies, BIPM and the U.S. Government Printing Office prescribe printing the degree symbol with a space between the degree symbol and the number, as in "10 °C".^[1][2] However, in many professionally typeset works, including scientific works, such as those published by The University of Chicago Press or Oxford University Press, the degree symbol is printed with no spaces between the number, the symbol, and the C or F representing Celsius or Fahrenheit, as in "10°C".^[3] This is also the practice of the University Corporation for Atmospheric Research which operates the National Center for Atmospheric Research.^[4] Still others place the space between the degree sign and the letter (10° C), in a manner probably no longer recommended by any of the major style guides.

[edit] Kelvin

Use of the degree symbol to refer to temperatures measured in kelvins (symbol: K) was abolished in 1967 by the 13th General Conference on Weights and Measures (CGPM). Therefore, the freezing point of water, for instance, is today correctly written as simply 273.15 K. The SI fundamental temperature unit is now "kelvin" (note the lower case), and no longer "degree Kelvin".

[edit] Input

• See Alt code and Unicode, section "Input methods" for general information on entering characters like this. The Unicode code point is U+00B0 (176 decimal), and the code point in CP437 etc is 0xF8 (248 decimal).
• On many Mac keyboard layouts, the character can be found on Option+Shift+8.
• The HTML entity °.
• On Linux and other Unix-like systems, many keyboard layouts allow typing the degree sign with AltGr+Shift+0.

Due to a similar appearance in some fonts in print and on computer screens, some other characters may be mistakenly substituted for it: the "masculine ordinal indicator" (U+00BA, º ), the "ring above" (U+02DA, ˚ , which appears on a Mac keyboard layout at Option+K), "superscript zero" (U+2070, ⁰ ), superscript zero proper ( ⁰ ) or superscript letter "o" ( ^o ), and the "ring operator" (U+2218, ∘ ).

[edit] References