A Chirping Elliptic Rocker

Sitting at the breakfast table, I noticed that a small cereal bowl placed within another larger one was rocking, and that the period became shorter as the amplitude died down. What was going on? The handles of the smaller bowl appeared to be elliptical in cross-section, so I considered how a rigid body shaped … Continue reading A Chirping Elliptic Rocker →

Joseph Fourier and the Greenhouse Effect

Jean-Baptiste Joseph Fourier, French mathematician and physicist, was born in Auxerre 251 years ago today. He is best known for the mathematical techniques that he developed in his analytical theory of heat transfer. Over the past two centuries, his methods have evolved into a major subject, harmonic analysis, with widespread applications in number theory, signal … Continue reading Joseph Fourier and the Greenhouse Effect →

The Kill-zone: How to Dodge a Sniper’s Bullet

Under mild simplifying assumptions, a projectile follows a parabolic trajectory. This results from Newton's law of motion. Thus, for a fixed energy, there is an accessible region around the firing point comprising all the points that can be reached. We will derive a mathematical description for this kill-zone (the term kill-zone, used for dramatic effect, … Continue reading The Kill-zone: How to Dodge a Sniper’s Bullet →

Hokusai’s Great Wave and Roguish Behaviour

Hokusai's woodcut “The Great Wave off Kanagawa”. “The Great Wave off Kanagawa”, one of the most iconic works of Japanese art, shows a huge breaking wave with foam thrusting forward at its crest, towering over three fishing boats, with Mt Fuji in the background [TM158 or search for “thatsmaths” at irishtimes.com]. This woodcut, produced by … Continue reading Hokusai’s Great Wave and Roguish Behaviour →