#### 05 Oct 20

A course aimed at people who have a strong sense that what Einstein did changed everything but do not know enough physics to understand what he did and why it was so important. The course presents just enough of Einstein’s physics to give students an independent sense of what he achieved and what he did not achieve.

#### 02 Sep 11

Most people use this web site to get information about a particular number sequence. If you are a new visitor, then you might ask the database if it can recognize your favorite sequence, if you have one.

#### 12 May 11

Encoding images under 140 characters.

#### 15 Mar 11

This manifesto is dedicated to one of the most important numbers in mathematics, perhaps the most important: the circle constant relating the circumference of a circle to its linear dimension. For millennia, the circle has been considered the most perfect of shapes, and the circle constant captures the geometry of the circle in a single number. Of course, the traditional choice of circle constant is π—but, as mathematician Bob Palais notes in his delightful article “π Is Wrong!”,1 π is wrong. It’s time to set things right.

#### 19 Dec 10

“Anyone who works with LaTeX knows how time-consuming it can be to find a symbol in symbols-a4.pdf that you just can’t memorize. Detexify is an attempt to simplify this search.”

#### 26 Oct 10

MathJax is an open source JavaScript display engine for mathematics that works in all modern browsers.

#### 20 Oct 10

“You should be aware that while Random() is usually uniformly distributed, Random()Random() is not. And so is Random()+Random().” - Belisarius Nice illustration of Central Limit theorem.

#### 17 Sep 10

R is an open source implementation of the S-Plus language. It is freely available and is licensed under the GPL. The language simplifies many statistical computations and can be a powerful tool.

#### 05 Feb 10

A non-technical introduction to Compressed Sensing

#### 23 Nov 09

A simple concrete example of how quantic computers work.

#### 13 Nov 09

This book, is supposed to teach methods of numerical computing that are practical, efficient, and (insofar as possible) elegant.