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Exhibit developer Erik Thogersen backs away from the Giant Mirror. Watch his image change as he passes through the focal point, then continues on past the center of curvature.

At the Giant Mirror, Senior Staff Scientist Paul Doherty demonstrates a simple way of locating a real image—an image that floats in space in front of the mirror.

Senior Staff Scientist Thomas Humphrey invents a simple experiment to see if the Giant Mirror is spherical or parabolic, and then to see if it's perfectly spherical. By placing a Styrofoam ball at the center of curvature, he's able to prove that the mirror is out of pure sphericity by about one-quarter of one degree.