Gravity-defying ramps take illusion prize

From Nature:

News.2010.233 In a packed concert hall, Kokichi Sugihara wields a pickaxe and mimes a blow to the stage. “I am a miner, and I have a secret,” Sugihara says, adjusting his hard hat and headlamp. “I have discovered a new super-magnet.”

A screen behind Sugihara begins playing a video. A cardboard structure appears, consisting of four ramps ascending to a raised platform. A hand places a wooden ball at the base of a ramp, and it rolls uphill, before stopping on the 'super-magnetized' platform. As the same trick is repeated for the other three ramps, the crowd lets out an “ooh”. Only there is no super-magnet, and Sugihara is no miner. He's a mathematician at Meiji Institute in Kawasaki, Japan, and his display is — officially — the world's best visual illusion. At least, according to the hundreds of vision scientists in the audience who have come to judge the sixth competition to find the Best Illusion of the Year, a satellite event of the Vision Sciences Society's annual meeting in Naples, Florida. Sugihara's gravity-defying marbles beat nine other finalists, chosen from 84 entries.

Vision scientists are not easily fooled — so how did Sugihara do it? All is revealed as the camera angle changes to show that what looked like four ordinary ramps leading up to a platform was really an intricate set-up of sheared support columns, skewed slide angles and ramps of different lengths, all of which were above the platform all along.

More here.