### The derivative of sin(x)

We know that we can use the limit definition     to compute the derivative of “from first principles”. And…

### Tuning and temperament (3): Just Intonation and Equal Temperament

We have seen in previous posts on this topic that: The perfect fifth corresponds to a frequency ration of 3/2…

### Tuning and Temperaments (2): Intervals and Pythagorean tuning

In the previous post we looked briefly at intervals, pitches and frequencies, and how to measure them.  We also showed…

### The size of the Solar System (and more)

I’ve been looking up at the sky at night recently, and thinking about the sizes of things.  Now it’s all…

### Neusis constructions (4): the Delian problem

The Delian problem is that of constructing ; since the polynomial equation is irreducible over the equation can’t be solved…

### Neusis constructions (3): the regular heptagon

The regular heptagon (seven sided polygon) is the smallest polygon which can't be constructed used Euclidean compass and straight-edge.  However,…

### “Neusis” constructions (1)

As you know, the geometry of the ancient Greeks, as exemplified by Euclid, restricted constructions to the use of unmarked…

### Solving a cubic by folding

Currently I’m reviewing “Origami5” for the Australian Mathematical Society. It’s a terrific volume, filled with nice papers about Origami as…

### MISG day 5

I didn’t explain the problem well enough in my last post: AGL, the energy supply company, are trying (among other things) to…

### MISG day 3

This week I’m at the Mathematics and Statistics Industry Study Group, a yearly event where companies from Australia and New…