Related Experiment Video
Updated: May 11, 2026
06:35
Using Gold-standard Gait Analysis Methods to Assess Experience Effects on Lower-limb Mechanics During Moderate High-heeled Jogging and Running
Published on: September 14, 2017
Changes in angular size and speed affect the judged height of objects moving over a ground surface
Junjun Zhang1, Myron L Braunstein, George J Andersen
1Department of Cognitive Sciences, University of California, Irvine, Irvine, CA 92697-5100, USA.
Perception
|May 18, 2013
Summary
Perceived object height is influenced by angular size and speed. Larger or faster-moving objects appear higher off the ground, especially when their final size is larger.
Area of Science:
- Visual Perception
- Depth Perception
- Motion Perception
Background:
- The perceived path of a moving object can be altered by manipulating its shadow.
- Previous research established the influence of shadows on perceived object motion.
Purpose of the Study:
- To investigate how angular size and speed affect the perceived height of a moving sphere.
- To determine the role of optical contact in indicating receding depth.
Main Methods:
- Utilized a
- ball-in-a-box
- scene to present a moving sphere.
- Conducted four experiments examining changes and constant levels of angular size and speed.
- Analyzed perceived height judgments based on visual cues.
Main Results:
- Increases in angular size or speed led to judgments of increased perceived height.
- The final angular size of the sphere significantly impacted judged height.
- Larger final sizes correlated with greater perceived height.
Conclusions:
- Angular size and speed are critical factors in judging the height of a moving object.
- The visual system integrates size and speed cues to estimate height above a ground plane.
- Final object size provides a salient cue for perceived height estimation in depth.
Related Concept Videos
01:11Angular Velocity and Acceleration
We previously discussed angular velocity for uniform circular motion, however not all motion is uniform. Envision an ice skater spinning with their arms outstretched; when they pull their arms inward, their angular velocity increases. Additionally, think about a computer's hard disk slowing to a halt as the angular velocity decreases. The faster the change in angular velocity, the greater the angular acceleration. The instantaneous angular acceleration is defined as the derivative of angular...
01:26Influence of Earth's Curvature and Atmospheric Refraction on Leveling
During leveling, the Earth's curvature and atmospheric refraction introduce deviations in the line of sight from a true horizontal reference. When the line of sight is leveled, it remains perpendicular to the plumb line only at a single point. Beyond this, it deviates due to the Earth’s curvature, represented by the correction C. For a sight distance D, the deviation can be derived using the relationship:This relationship shows that the deviation increases quadratically with distance. Over a...
01:09Relating Angular And Linear Quantities - I
If the rotational definitions are compared with the definitions of linear kinematic variables from motion along a straight line and motion in two and three dimensions, we can observe a mapping of the linear variables to the rotational ones.
When comparing the linear and rotational variables individually, the linear variable of position has physical units of meters, whereas the angular position variable has dimensionless units of radians, as it is the ratio of two lengths. The linear velocity...
When comparing the linear and rotational variables individually, the linear variable of position has physical units of meters, whereas the angular position variable has dimensionless units of radians, as it is the ratio of two lengths. The linear velocity...
01:20Variation in Acceleration due to Gravity near the Earth's Surface
An object's apparent weight is its weight measured by a spring balance at its location. It is different from its true weight, the force with which the Earth pulls it, because of the Earth's rotation. Mathematically, an object's apparent weight equals its true weight minus the centripetal force that keeps it in a circular motion along with the Earth's surface every 24 hours.
The difference between the true and apparent weights is proportional to the square of the Earth's angular speed. Since the...
The difference between the true and apparent weights is proportional to the square of the Earth's angular speed. Since the...
01:26Rotational Motion about a Fixed Axis
A rigid body's rotation around a fixed axis makes every point within it trace a circular path around a specific line or point. The term given to this type of spinning is defined by the angular position, symbolized by the angle θ. This angle is gauged from a static reference line to the revolving object. From this angular position, any variation is referred to as angular displacement, denoted by dθ. The extent of this displacement can be calculated in degrees, radians, or revolutions, where one...
01:08Angular Velocity and Displacement
Uniform circular motion is motion in a circle at a constant speed. Although this is the simplest case of rotational motion, it is very useful for many situations and is used to introduce rotational variables. When a particle is moving in a circle, the coordinate system is fixed and serves as a frame of reference to define the particle’s position. Its position vector from the origin of the circle to the particle sweeps out the angle θ, which increases in the counterclockwise direction as the...