Inverse Square Law Model

In this exhibit a light source shines through a screen with a square array of small holes in it projecting a series of dots on a movable screen. The farther back the screen, the more widely spaced the dots become. The visitor can count the number of dots enclosed by a square on the screen at a given distance from the light source. If the distance is doubled, the number of dots within the square is reduced to 1/4 of its previous value ( the inverse square.)