A variety of communications-related play things for visitors of all ages.
Visitors in pairs can use two large parabolic reflectors placed a distance apart to communicate with each other. They experiment to find the focus points of the paraboloids.
Visitors can use three binoculars to observe distant things.
Visitors can enter a giant kaleidoscope. They will see themselves looking into infinity.
Visitors can use a periscope mounted to look over obstructions and see what is otherwise invisible.