An article which gives an account of some properties of magic squares.
When you think of spies and secret agents, you probably wouldn’t think of mathematics. Some of the most famous code breakers in history have been mathematicians.
This short article gives an outline of the origins of Morse code and its inventor and how the frequency of letters is reflected in the code they were given.
For more information and diagrams see: http://stars.astro.illinois.edu/celsph.html
Here is a link to a collection of films to show the position of the sun and the ecliptic. http://brahms.phy.vanderbilt.edu/~rknop/astromovies/
The link to this film shows the movement of the Sun around the ecliptic http://brahms.phy.vanderbilt.edu/~rknop/astromovies/ecliptic.avi