Related Experiment Video
Updated: Jun 26, 2025

Finite Element Modeling for the Simulation of the Quasi-Static Compression of Corrugated Tapered Tubes
Published on: January 6, 2023
The inner tube effect
Ian M Thornton1, Sunčica Zdravković2,3, Dejan Todorović3
1Department of Cognitive Science, Faculty of Media and Knowledge Sciences, University of Malta, Msida, Malta.
Abstract:
We describe a novel size illusion in which targets appear to either shrink or grow when enclosed within a narrow tube. The direction of size change is determined by the contrast step between display elements. We first noticed this effect in the context of the dynamic "rocking line" illusion (RLI), but it can also be easily seen in completely static displays. As with the RLI, the overall scale of the display seems to play an important role. We provide an online, interactive demo, enabling the reader to explore the relevant parameter space.
Related Concept Videos
Steady, Laminar Flow in Circular Tubes
Excess Pressure Inside a Drop and a Bubble
Bernoulli's Principle: Applications
Entrainment devices use a high fluid speed to create low pressures and, thus, entrain one fluid into another. Some examples of these devices are given below:
Rise of Liquid in a Capillary Tube
Thin-Walled Hollow Shafts
Pascal's Law

