In 1859, the English mathematician Arthur Cayley published a note in the Philosophical Magazine, entitled *On Contour and Slope Lines*, in which he examined the structure of topographical patterns. In a follow-up article, *On Hills and Dales*, James Clark Maxwell continued the discussion. He derived a result relating the number of maxima and minima on a contour chart.

## Archive for March, 2013

### The Pitch Drop Experiment

Published March 21, 2013 Irish Times Leave a CommentTags: Fluid Dynamics, Physics

Later this year a big black blob of sticky pitch will plummet from a funnel and plop into a beaker. The story is recounted in this week’s *That’s Maths* ( TM017 ) column in the *Irish Times*.

In one of the longest-running physics experiments, the slow-flowing pitch, under a bell-jar in the University of Queensland in Brisbane, will ultimately lose its battle with gravity …

### Happy Pi Day 2013

Published March 14, 2013 Occasional Leave a CommentTags: Archimedes, Number Theory, Pi

Today, 14th March, is Pi Day. In the month/day format it is 3/14, corresponding to 3.14, the first three digits of π. So, have a Happy Pi Day. Larry Shaw of San Francisco’s Exploratorium came up with the Pi Day idea in 1988. About ten years later, the U.S. House of Representatives passed a resolution recognizing March 14 as National Pi Day.

Today is also the birthday anniversary of Albert Einstein, giving us another reason to celebrate. He was born on 14 March 1879, just 134 years ago today.

Continue reading ‘Happy Pi Day 2013’

### CT Scans and the Radon Transform

Published March 7, 2013 Irish Times 5 CommentsTags: Algorithms, medicine

Last December, Dublin’s Tallaght Hosptal acquired a new CT scanner, a Toshiba Aquilon Prime, the first of its type in the country. The state-of-the-art scanner is housed in a room with a ‘sky ceiling’ that allows patients to enjoy an attractive outdoor image during the scanning process.

This equipment, which cost €600,000 will undoubtedly result in timely treatment of patients and the saving of lives. The process of generating images from CT scans is described in the latest *That’s Maths* column (TM016) in the Irish Times.

In his scientific best-seller, *A Brief History of Time, *Stephen Hawking remarked that every equation he included would halve sales of the book, so he put only one in it, Einstein’s equation relating mass and energy, *E*=*mc*^{2}.

There is no doubt that mathematical equations strike terror in the hearts of many readers. This is regrettable, as equations are really just concise expressions of precise statements. They are actually quite user-friendly and more to be loved than feared. Continue reading ‘More Equal than Others’