The University of Mars — Encyclopedia
Demonstrates the inverse square law of light with a two model stars and two detectors (space telescopes).
The stars' luminosities and the detectors' distances can be adjusted with the vertical and horizontal sliders, respectively, to see how they affect the "brightness" (flux) reading.
There are two stars and detectors to allow side-by-side comparisons.
Thanks to:
Astronomy Education at the University of Nebraska-Lincoln for the inspiration!
(UNL-Astro original)