This number represents the extent of the figure D as seen from a point O in space, and is usually expressed in steradians. Steradians are a supplementary unit of the International System of Units, and their symbol is sr. A cone is formed by the complete half line that passes through point D, with O as its end. This is the solid angle, and its size is measured by the area of the part on the sphere when it is cut with a sphere of radius 1 centered at O. In particular, the solid angle of the entire space as seen from O is 4πsr, and the solid angle of the half space is 2πsr. [Minoru Kurita] Source: Shogakukan Encyclopedia Nipponica About Encyclopedia Nipponica Information | Legend |
空間で一点Oから図形Dを見る広がりを表す数で、普通ステラジアンsteradian単位で表す。なお、ステラジアンは国際単位系の補助単位で、記号はsr。Oを端としてDの点を通る半直線全体でできる錐(すい)をつくる。これが立体角で、その大きさは、これをOを中心とする半径1の球面で切るとき、球面上にできる部分の面積で計る。とくに、Oから見た全空間の立体角は4πsrであり、半空間の立体角は2πsrである。 [栗田 稔] 出典 小学館 日本大百科全書(ニッポニカ)日本大百科全書(ニッポニカ)について 情報 | 凡例 |
<<: Intersection - highway grade separation
>>: Stereochemistry - Rittaikagaku (English spelling) stereochemistry
...In many cases, they were built as imarets (or ...
...It has no leaves, a jointed stem, and is flat ...
731‐798 Arab Islamic jurist. A native of Kufa, he ...
Home drama is a type of drama that uses everyday e...
… [Eiichi Asayama]. … *Some of the terminology th...
…The Warbler Finch, Certhidea olivacea , feeds on...
British author I. Fleming's novels, from Casin...
...In recent years, noteworthy painters have also...
…Official name: Italian RepublicRepubblica Italia...
1436-1476 A military commander of the Muromachi p...
An old town in Kitakatsushika County, northeastern...
...the organizational structure of the Toyotomi g...
…A Central European republic that existed from 19...
German playwright and poet. Born in Silesia to a ...
…[Kazuo Furusato]. … *Some of the terminology tha...