Sharing my personal interests.

Investigations into mathematics -- group theory, integrals, continued fractions, matrices, geometry and more.

Also music and art: the acoustics of the violin family of instruments, music created by computer, plus some paintings, drawings and local history .


Welcome to John Coffey's web site of interesting finds.

This site is for maths students and amateurs who enjoy exploring maths, music, and acoustics. I am not a professional mathematician, musician nor artist, so there are no high-powered research papers here -- just the work of an enthusiast.

The latest additions include some paintings and drawings plus

1) Drawing in perspective: How simple objects appear when drawn accurately. This includes a section on how computer graphics software rotates an object, plus an account of non-linear perspective using the map projections. A supporting article describes spherical triangles,

2) A simple question about a ladder leaning against a wall which leads to intriguing maths of ellipses and the astroid curve.

3) An attempt to find the largest sofa which can be manoeuvred round a 90 degree corner in a corridor (with animation). This is supported by statistics on the error in measuring the area of an arbitrary plane figure by counting the number of lattice points inside it.

Click the buttons above particular topics,

or here for an overview of contents and other topics

John Coffey, Cheshire, England, June 2024