They demonstrated the trick in a windowless room on the Boston University campus, where Goyal works as an electrical engineering professor. In the room, a flatscreen monitor displayed a series of crude drawings created by Goyal’s graduate student, Charles Saunders. Among them were several masterpieces: A mushroom that resembles Toad from Mario Kart, a Simpsons-yellow dude wearing a sideways red baseball cap, the red letters “BU” for school pride. These are the images that Goyal and his team wanted to capture while pointing the camera lens in a completely different direction.
In the darkened room, the flickering of the screen produced a dim, blobby blur on the opposite wall. Using a camera mounted on a tripod, Saunders took 20 quick snaps of the blob, for a total exposure time of three seconds, and fed it all into a computer program. A few minutes later—voilà: A blurred image of Toad, slightly askew, popped up on their screen.
“This is not magic,” Goyal tells me, in case anyone was confused.
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