Questions tagged [solid-angle]

Analogue of radians on spheres. A sphere has solid angle $4\pi$ comparing to the $2\pi$ radian for a circle.

124 questions
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Is there a reason why a differential solid angle is represented by a cone?

Just wondering... is there a geometric reason why a differential solid angle is usually represented by a cone? I cannot see that given the formula $$ d\Omega = \sin \theta \, d\theta \, d\phi $$ I cannot see that.
user8469759
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Solid angle definition - can it be seen shown using an image?

How do we show on a picture that a solid angle equals to this equation i found on a Wikipedia: \begin{align} \Omega =\!\!\!\int\limits_{\vartheta =0}^{\pi}\int\limits_{\varphi=0}^{2\pi}\underbrace{\sin\vartheta\, \textrm{d}\vartheta\,…
71GA
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How to find out the solid angle subtended by a tetrahedron at its vertex?

Given that the angles between the consecutive lateral edges AB, AC & AD meeting at the vertex A of a tetrahedron ABCD are $ α, β, γ$ (as shown in the diagram below). Is there any set-formula to find out the solid angle subtended by the tetrahedron…
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What is the solid angle substended by a point on some closed surface?

I'm trying to find out the solid angle subtended over the entirety of some closed surface S by some point P located on the surface. For a point within the surface, the answer is of course 4$\pi$, but I'm trying to get the result if that point were…
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Fraction of Solid Angle

I wonder which way is the correct way to calculate a specific fraction of a solid angle. I divided a hemisphere into a number of solid angles by using weights of gauss quadrature in the zenith direction ($W_j$) and in the azimuthal direction…
Elad
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Orienting a solid angle

I'm working on a project in which I need to somehow define oriented solid angle in Cartesian coordinate system, similar to how "regular" oriented angle is defined. And well, I have no idea how to do it. I thought about some plane with one point…
Proki
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