Note to users. If you're seeing this message, it means that your browser cannot find this page's style/presentation instructions -- or possibly that you are using a browser that does not support current Web standards. Find out more about why this message is appearing, and what you can do to make your experience of our site the best it can be.

Science 24 April 1970:
Vol. 168. no. 3930, pp. 464 - 467
DOI: 10.1126/science.168.3930.464
Prev | Table of Contents | Next

Articles

Distortions of Apparent Velocity: A New Optical Illusion

J. T. Enright 1

1 Scripps Institution of Oceanography, University of California, La Jolla

To an observer whose one eye is covered with a relatively strong filter (approximately 90 percent extinction) and who views a landscape from the side window of a moving automobile, the velocity of the vehicle appears to be markedly reduced when the uncovered eye is in the forward or leading position (in the sense of motion of the vehicle); the velocity seems to be increased when the covered eye is in the leading position. The illusion of reduced velocity is accompanied by an apparent dwarfing of objects near the roadside and an apparent foreshortening of the distance between object and observer; the illusion of increased velocity is accompanied by an apparent increase in size of objects and an increase in their apparent distance. These illusions can be understood as corollaries of the well-known Pulfrich phenomenon.


THIS ARTICLE HAS BEEN CITED BY OTHER ARTICLES:
Pulfrich's phenomenon in unilateral cataract.
S. M Scotcher, D A. H Laidlaw, C. R Canning, M. J Weal, and R. A Harrad (1997)
Br J Ophthalmol 81, 1050-1055
   Abstract »    Full Text »    PDF »
Baseball Hitting, Binocular Vision, and the Pulfrich Phenomenon.
A. J. Hofeldt, F. B. Hoefle, and B. Bonafede (1996)
Arch Ophthalmol 114, 1490-1494
   Abstract »    PDF »


To Advertise     Find Products

Science. ISSN 0036-8075 (print), 1095-9203 (online)