The Depth Effect of an Oscillating Tilted Bar

✍ Scribed by L. Beghi; E. Xausa; L. Tomat; M. Zanforlin

• Publisher: Elsevier Science
• Year: 1997
• Tongue: English
• Weight: 316 KB
• Volume: 41
• Category: Article
• ISSN: 0022-2496
• DOI: 10.1006/jmps.1997.1143

✦ Synopsis

An oblique line segment moves on the frontal plane. One extremity is fixed while the other oscillates from left to right at uniform speed along a horizontal line. After a few seconds of observation, the segment appears as a bar oscillating in depth and longer than its maximum length when stationary on the frontal plane. From a perspective point of view the moving segment can be a 2D projection of a rigid bar of any length; in order to explain how the bar appears of a well defined length, a new hypothesis is here advanced. The hypothesis is based on a process of minimization of the relative velocity differences between the various points of the segment. The mathematical model here presented allows quantitative predictions of the apparent length of the bar and qualitative predictions of its apparent movement. These predictions that are well supported by the experimental results.