Slope illusion 10
Outdoor tilt illusion where an ascending slope appears to descend or a descending slope appear to ascend
e.g. Magnetic Hill in Canada; Wikipedia
since April 3, 2013
A survey of the skewed staircase illusion in Shomaru station of Seibu-Chichibu line, Saitama-prefecture, Japan
March 13, 2013, reported by Akiyoshi Kitaoka and Seiichi Tsuinashi, supported by a JSPS kaken-hi grant and R-GIRO
The Shomaru staircase
Copyright Akiyoshi Kitaoka 2013 (March 13) photo Fenruary 13, 2013
The steps of this staircase are horizontal, but upper steps appear to tilt down to the right when observed from below. Moreover, the middle handrail stands vertically, but it appears to tilt down to the left.
Akiyoshi also sees an "ascending staicase" illusion.
The steps of this staircase are horizontal, but lower steps sometimes appear to tilt up to the right when observed from below.
The steps of this staircase are horizontal, but they occasionally appear to tilt down to the left when observed from above.
The middle handrail stands vertically, but it appears to tilt down to the right when observed from above.
The middle handrail stands vertically, but it appears to tilt down to the left when observed from below.
Dr. Seiichi Tsuinashi was examining whether a prop of the middle handrail was vertical.
The staircase observed from a distant point
Shomaru station
Seibu railway cars
Comparison with the staircase of the Shigaraki Ceramic Cultural Park
Copyright Akiyoshi Kitaoka 2008 (April 21)
Comparison with the staircase of the Daijingu bridge in Kyoto
Copyright Akiyoshi Kitaoka 2013 (March 30)
Reference
Tsuinashi, S. (2005). The study of skewed staircase illusion. Japanese Journal of Psychology, 76, 139-146. https://www.jstage.jst.go.jp/article/jjpsy1926/76/2/76_2_139/_pdf
Seiichi's slope illusion pages
Slope illusion 9 (Illusory slope in Minamitane-town, Tanegashima-island, Kagoshima, Japan)
Slope illusion 8 (Illusory slope in Nakatane-town, Tanegashima-island, Kagoshima, Japan)
Slope illusion 7 (Danjo-zaka and Okyo-zaka in Amakusa-Shimojima, Kumamoto, Japan)
Slope illusion 6 (Slope-ascending river in Miyama, Nantan, Kyoto, Japan)
Slope illusion 5 (Ghost slope in Okagaki, Onga-county, Fukuoka, Japan)
Slope illusion 4 (Slope-ascending water in Tanushimaru, Kurume, Fukuoka, Japan)
Slope illusion 3 (moving-back slope in Hashikami, Aomori, Japan)
Slope illusion 2 (Mysterious slope in Towa, Iwate, Japan)
Slope illusion 1 (Mystery zone in Yashima, Takamatsu, Kagawa, Japan, etc.)