Campfire shadows

Someone close to the fire blocks a wide slice of its light. The same-sized person, farther out, blocks a narrow slice.

An electron near the nucleus shields more of its charge for the same reason: up close, it covers a wider angle. Farther out, the shield is weaker.

The ring around the fire is the angle each person blocks. The dark wedge beyond them is the shadow that angle casts.

Blocked angle = 2·sin⁻¹(r / d)

People

    Click the ground to place someone. Drag to move them. Press Delete to remove the selected person, or the arrow keys to nudge them.