Author Archives: David Orden

David Orden
PhD in Mathematics (Universidad de Cantabria, 2003), associate professor of applied mathematics at the Universidad de Alcalá. His main research interests are Discrete and Computational Geometry, Graph Theory, and their applications to other fields.

Security in residential and public areas is a matter of great importance for many people. This is why some Internet providers are offering surveillance systems as a value-added service. Such surveillance systems have recently shifted from CCTVs to IP-based cameras, […]

This post is dedicated to the memory of Professor Ferran Hurtado, inspirational friend and colleague. . Triangulations are extremely useful in computer graphics, with terrain modeling being an outstanding example: A mesh of points in 2D is triangulated and then the […]

Triangles are, definitely, among the most used mathematical objects. One of the reasons is that they are simple (actually the smallest polygon). Another very important reason is that they are rigid, which is the property behind the many structures composed […]

We all know how Spider-Man moves through the city, shooting spider-webs from wall to wall. But, have you ever wondered if he is actually using the shortest route? And, if so, how does he compute it? Since walls introduce […]

An old problem, restated by Martin Gardner in 1959, asked if six cigarettes that can be placed so that each touches the other. Gardner was surprised by fifteen readers discovering that actually seven cigarettes can be arranged with that […]

When was the last time you used a postage stamp? Even if it was a long time ago, you may have hold in your hands a strip of stamps. Maybe you have even tried to fold it into a stack, […]

Imagine you are the owner of a hot dog stand and, after many stressful years in the streets of New York City, you are moving the business to the countryside. Of course, you want all the potential users to have […]

Questions on the digit expansion of mathematical constants, such as , , or have fascinated mathematicians for centuries. However, many of these questions remain elusive to the efforts of researchers. For instance, it is not known for sure if the […]

Visual illusions, a perceptual behavior where what we “see” differs from the physical reality, are used in vision science to understand the nature of human perception. Most of the known visual illusions come from 2D pictures and their motions, but […]

Imagine you were a watchman, having to patrol some streets. Today you were assigned to straight, well-illuminated, and wide streets, that can be checked with a glance from the intersection. Before starting the route, you want to determine the shortest […]