Solid Angle Simulation
Explore how radius and intercepted curved surface area affect the value of solid angle.
Best experience: run the simulation in full screen so the 3D model, controls, live output, and explanation remain visible together.
3D Solid Angle Model
Drag inside the box to rotate the 3D model
Ω = A / r²
Controls
Radius range: 1 to 6 units
Allowed area depends on radius.
Surface area was adjusted because it cannot be greater than the total surface area of the sphere.
Visual guide:
Blue patch = intercepted curved area A
Purple cone = solid-angle region Ω
r = radius from centre to sphere
Blue patch = intercepted curved area A
Purple cone = solid-angle region Ω
r = radius from centre to sphere
Live Output
Radius
3.0 units
Intercepted Area
12.0 square units
Solid Angle
1.33 sr
Part of Full Sphere
10.6%
Concept: A solid angle tells us how much of a sphere is covered by a curved surface patch as seen from the centre.
If the intercepted area increases, the solid angle increases. If the radius increases while the same area is intercepted, the solid angle decreases.