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A Gaussian surface is a closed surface in three-dimensional space through which the flux of a vector field is calculated; usually the gravitational field, the electric field, or magnetic field.〔Essential Principles of Physics, P.M. Whelan, M.J. Hodgeson, 2nd Edition, 1978, John Murray, ISBN 0-7195-3382-1〕 It is an arbitrary closed surface ''S'' = ∂''V'' (the boundary of a 3-dimensional region ''V'') used in conjunction with Gauss's law for the corresponding field (Gauss's law, Gauss's law for magnetism, or Gauss's law for gravity) by performing a surface integral, in order to calculate the total amount of the source quantity enclosed, i.e. amount of gravitational mass as the source of the gravitational field or amount of electric charge as the source of the electrostatic field, or vice versa: calculate the fields for the source distribution. For concreteness, the electric field is considered in this article, as this is the most frequent type of field the surface concept is used for. Gaussian surfaces are usually carefully chosen to exploit symmetries of a situation to simplify the calculation of the surface integral. If the Gaussian surface is chosen such that for every point on the surface the component of the electric field along the normal vector is constant, then the calculation will not require difficult integration as the constants which arise can be taken out of the integral. == Common Gaussian surfaces == Most calculations using Gaussian surfaces begin by implementing Gauss's law (for electricity):〔Introduction to electrodynamics By: Griffiths D.J〕 : Thereby ''Q''(''V'') is the electrical charge contained in the interior, ''V'', of the closed surface. This is Gauss's law, combining both the divergence theorem and Coulomb's law. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Gaussian surface」の詳細全文を読む スポンサード リンク
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