Riders on the Hong Kong Peak Tram continue to perceive that skyscrapers are falling down, despite their knowledge that the buildings are structurally sound.
Our vision overrides our sense of gravity -- and our common sense -- to create a tenacious illusion of tilt, researchers from the University of Hong Kong and the University of Freiberg have found. At night, the effect is even worse. Standing, on the other hand, can reduce the illusion -- perhaps by raising a rider's awareness of the force of gravity.
The study, "Falling Skyscrapers: When Cross-Modal Perception of Verticality Fails," is published in Psychological Science, required hundreds of trips up Hong Kong's Victoria Peak. Even for experienced riders, the illusion that buildings were tipping over was persistent.
Graphic courtesy of Chia-huei Tseng et al.
Top image: Tyrone Siu/Reuters.