Constructing the Catacaustic of an Ellipse - Radial Rays
- Irina Boyadzhiev
A light source at the radiant point S produces some radial light rays (in yellow). The rays are reflected by the ellipse, with semi-major axis and a semi-minor axis. If the rays have more than one intersection point with the ellipse, they are reflected at both points. The reflected rays and their continuations are shown in light blue. Definition: The envelope of the reflected rays by the ellipse is called the catacaustic of the ellipse (also called caustic).
- Drag the slider - "numberRays" to change the number of light rays.
- Drag the slider - "d" to change the distance from the center of the ellipse to the radiant point.
- Drag the slider -"α" to rotate the radiant point around the center of the ellipse.
- Sliders a and b will change the dimensions of the ellipse.