Sunday, January 13, 2013

Ball in gravity and air drag

My sister in law is an intelligent fine young woman, and a high school teacher, living in France.

Over the last 2 years,  traditional education in the US has been seriously shaken by the sudden and massive popularity of online courses, as the coming of age of web technologies has made them possible for teachers and pleasant for students.

The breakthrough came from Salman Khan who founded the now famous (and fantastically useful ! - not just to students) Khan Academy. The first unsolicited feedback he got from his youtube viewers say a lot about the depth of the demand for good quality education/instruction. In hindsight, it need not be that big a surprise, as the irrepressible urge to know/learn/discover is quintessentially human, particularly among young people. After all wikipedia, another spectacular success driven by people's appetite for knowledge, had already surpassed centuries old institutions like the Encyclopedia Britannica. And his extraordinary success, signalled by a Forbes' cover page, is all the more noticeable than his endeavor is not-for-profit.

At university level, the first foray into MOOC (massively open online courses) came from, I believe, Stanford's professors Sebastian Thrun and Peter Norvig with they Artificial Intelligence class in the last quarter of 2011. Surprised by the number of applicants (more than 50,000 !), and impressed by the potential impact, they founded Udacity. Many universities have quickly followed suit and soon after founded Coursera, which aggregates online courses from many universities, and edX, created by Harvard and Berkeley. Everybody clearly feels the trend and jockeys hard to capture audiences.

Sunday, January 6, 2013

Pythagorean Theorem

In the first weeks of December, as I was thinking of acceptable Christmas presents for my friends/family. Strolling in department stores, I caught a glimpse a tablet - not an iPad/Android like tablet, but  - a drawing tablet ! I was convinced instantly. Then I dug into the realm of Wacom/Bamboo products and soon was completely carried away by the potential of such devices. Soon after I had bought and was testing it.

It is a great potential replacement of a mouse, absolutely fantastic for drawing, and a tool of choice to do Khan Academy's style video tutorials.
As a drawing soft, Sketchbook Express, available on the Mac App Store, is convenient: free, simple, beautiful.

Pleased by my new device, I started off recording (in French) a few tutorials, as a first exercises. The screen capture soft used is Snagit (Camtasia is even better with additional editing features).

Below is the simplest demonstration of the Pythagorean theorem, in my view, as the only thing you need to know are the formulae for the area of a square, and a right triangle. Not Thales/Cos/Sin/etc.

It is not a pedagogical master piece but relatively decent for a first trial, which says a lot, again, about the potential of drawing tablets+video screen capture as means to convey relatively complex messages.

The shopping season proved quite interesting..
I kept my tablet and offered two.

Tuesday, January 1, 2013

Deutschland, Bundesländer - Karte

Recently I have been experimenting with the impressively well thought and powerful d3.js javascript library. The capabilities of the library are jaw dropping and the quality of the rendering, on some examples is quite amazing, and the idea to have built it directly on top of the web standards is simply brilliant. This last design decision is so powerful that this library stands a chance to become a standard itself.

In practise I am also learning the basics of HTML+CSS+Javascript, so in order to be able to make some d3 data visualisation, I am forced to sometimes long digressions..

It is to be noted that the d3.js learning curve is quite steep, in spite of several very good quality tutorials available. The first one I read was written by Scott Murray. Very good.

Below a dynamic map of the 16 federal states that make Germany, designed to help me learn them (on top of helping me learn d3.js).
The code is available on