# Xah Math Blog Archive 2013-01 to 2013-02

a blog by Glenn Wilcox with lots beautiful math-related pictures generated in Rhinoceros 3D @ http://www.generativedesigncomputing.net/

O, math, my true love, but how i have alienated thee, and you being quite difficult.

### Microwave Arithmetic

on a microwave, you press 2 0 0 for 120 seconds, but 1 2 0 for 80 seconds, yet 9 0 for 90 seconds.

can you establish the rules for microwave number system or microwave arithmetic?

### linear algebra comics

thx to weizhoupan

### Doyle spiral + Mobius transformation

can you identify what function is this?

it looks like a Mobius Transformation. But what's the exact parameters and what's the input image? (assume each ball is just a dot.)

Mobius Transformation is a function of the form `f[z] = (a z + b) / (c z + d)`

and `a d − b c ≠ 0`

. The variables are all complex numbers.

For a simple geometric explanation of complex numbers, see: Isometries: Translation, Rotation, Reflection and Mandelbrot Set Explained (no complex number needed).

recursion bonanza: Teacup Recursion Animation

5-Point Conics (needs Java installed.)

### Logic Based Human Language: Lojban

Lojban is a constructed language, design based on predicate logic. Some tutorial here, with voice recording: Xah's lojban Tutorial.

### Alice in Wonderland, Zero-sum game

“The more there is of mine, the less there is of yours.”

That's the concept of Zero-sum game. However, in real world, most things isn't zero-sum game. Both parties actually benefit. ➢ for example: when you give something you no longer want to someone, a value is created “out of nothing”.