Related Experiment Video
Updated: Aug 13, 2026

Experiments on Ultrasonic Lubrication Using a Piezoelectrically-assisted Tribometer and Optical Profilometer
Published on: September 28, 2015
Is vision metric? Comment on Lappin and Love (1992)
1Purdue University, West Lafayette, Indiana.
Abstract:
In a recent paper, Lappin and Love (1992) showed that depth judgments, based on planar motion of a stimulus, are remarkably precise. This led them to the conclusion that perception of planar motion allows acquiring metric information about visual space. We show, however, that Lappin and Love's stimuli contained 2-D cues in the frontal plane that could subserve the subject's judgments. This means that high precision in this task does not necessarily imply metric structure of visual space.
Related Concept Videos
Vision
Rolling With Slipping
An object's rolling motion is characterized by its rotation around its axis, while linear motion refers to the object's translational motion along a surface. Frictional forces can affect...
Glassware Calibration
Volumetric flasks: Volumetric flasks are designed to prepare aqueous solutions of precise volumes accurately with a calibration line on the neck. To calibrate a volumetric flask, it is important to fill it with distilled...
Distance Measurements by Taping
Sight Distance in a Vertical Curve
The Ratio Test

