Try to wrap a football in aluminium foil and you will discover that you have to crumple up the foil to make it fit snugly to the ball. In the same way, it is impossible to represent the curved surface of the Earth on a flat plane without some distortion.** ** [See this week’s *That’s Maths* column (TM068): search for “thatsmaths” at irishtimes.com].

## Posts Tagged 'Geophysics'

### Mercator’s Marvellous Map

Published May 21, 2015 Irish Times Leave a CommentTags: Geometry, Geophysics, Spherical Trigonometry

### The Hodograph

Published April 9, 2015 Occasional Leave a CommentTags: Astronomy, Fluid Dynamics, Geophysics

The Hodograph is a vector diagram showing how velocity changes with position or time. It was made popular by William Rowan Hamilton who, in 1847, gave an account of it in the Proceedings of the Royal Irish Academy. Hodographs are valuable in fluid dynamics, astronomy and meteorology.

### Mode-S: Aircraft Data improves Weather Forecasts

Published April 2, 2015 Irish Times Leave a CommentTags: Algebra, Geometry, Geophysics

A simple application of vectors yields valuable new wind observations for weather forecasting [see this week’s *That’s Maths* column (TM065) or search for “thatsmaths” at irishtimes.com].

Continue reading ‘Mode-S: Aircraft Data improves Weather Forecasts’

### Falling Bodies [1]: Sky-diving

Published November 13, 2014 Occasional Leave a CommentTags: Fluid Dynamics, Geophysics, Mechanics

Aristotle was clear: heavy bodies fall faster than light ones. He arrived at this conclusion by pure reasoning, without experiment. Today we insist on a physical demonstration before such a conclusion is accepted. Galileo tested Aristotle’s theory: he dropped bodies of different weights simultaneously from the Leaning Tower of Pisa and found that, to a good approximation, they hit the ground at the same time.

### El Niño likely this Winter

Published November 6, 2014 Irish Times Leave a CommentTags: Fluid Dynamics, Geophysics, modelling, Physics

This week’s *That’s Maths* column in *The Irish Times* (**TM056** or search for “thatsmaths” at irishtimes.com) is about El Niño and the ENSO phenomenon.

In 1997-98, abnormally high ocean temperatures off South America caused a collapse of the anchovy fisheries. Anchovies are a vital link in the food-chain and shortages can bring great hardship. Weather extremes associated with the event caused 2000 deaths and 33 million dollars in damage to property. One commentator wrote that the warming event had “more energy than a million Hiroshima bombs”.

### Gauss’s Great Triangle and the Shape of Space

Published July 10, 2014 Occasional Leave a CommentTags: Gauss, Geophysics, Maps

In the 1820s Carl Friedrich Gauss carried out a surveying experiment to measure the sum of the three angles of a large triangle. Euclidean geometry tells us that this sum is always 180º or two right angles. But Gauss himself had discovered other geometries, which he called non-Euclidean. In these, the three angles of a triangle may add up to more than two right angles, or to less.

Continue reading ‘Gauss’s Great Triangle and the Shape of Space’

### Breaking Weather Records

Published April 24, 2014 Occasional Leave a CommentTags: Geophysics, Number Theory, Probability

In arithmetic series, like 1 + 2 + 3 + 4 + 5 + … , each term differs from the previous one by a fixed amount. There is a formula for calculating the sum of the first *N* terms. For geometric series, like 3 + 6 + 12 + 24 + … , each term is a fixed multiple of the previous one. Again, there is a formula for the sum of the first *N* terms of such a series. Continue reading ‘Breaking Weather Records’