Parabolic reflector

I had an idea for a parabolic reflector, or at least how to make one. I saw a youtube video on making a cement mold, and using that mold with a ferrocement blank to make a dish out of ferrocement.

But I was thinking, that a basic mold could be made with ferrocement, and then spun to have a parabolic form induced. As long as the spinning is kept up till the cement is set, the form should hold. And better yet, if the cement is wet enough, it should have a very smooth surface... The main difficulty should be spinning the mold at a constant speed.

A good look at parabolic reflector based cookers can be found at the solar Cooking website.

Digital Learning

Here is an email I sent to a friend with respect to digital (online) sources and ideas for teaching. (sorry about the poor spanish, but the links are the important thing.)

 Te lo mencion sobre unas recursos de aprendizaje el la internet, aqui va una ligas. El primero es una video sobre "digital learning" presentado de la fundador de la Khan Academy (que es el segunda link.) una video sobre digital learning:

Khan Academy

El otro es un grabación de una buena presentación sobre educación, me gusta parte de la idea, pero se olvida y simplifica al aspecto de una maestro humano: Digital Aristotle:  (la idea es muy parecido de una libro de Neil Stephenson que se llama "The Diamond Age".)

Otras videos interesantes en youtube The Periodic Table of videos

Smarter Every Day

Una video sobre math que es muy interesante de ViHeart

me gusta mas los videos:
Hexaflexagons
Doodling in Math Class
What was up with Pythagoras?
Doodling in math class; Snakes + Graphs:

JPL news (space stuff)

Una documentaries desde los 90's que se llama Connections, algunos son muy buenos:

Platicas Rapidos (5min) que se llama 'Ignite'

One Minute physics

Six symbols

Back to CAD

I'm so very excited! Since starting work with renewable energy the idea of doing opensource design has been central to my task, and until two days ago the dream had become paralyzed. The problem was with code. There are many great ways to openly collaborate, but they all use code; essentially text. GitHub is one great example. But all of the designs that we have realized have been done in Google Sketchup; it was the only free, cross platform, and powerful CAD program found, and its files are all binary. But two days ago while showing a new student the git repository for the Amo-Esclavo Heliostat project I did a search for CAD and found openSCAD !

There are several good tutorials on using this package, but after watching Galvian's video I was hooked, and impressed. And aperently openSCAD plays well with the MakkerBot
project, with is also very handy to eliminate frequent trips to the metal shop. I am now planning on moving all my designs over to openSCAD!



Next we need an open, text based solution to electronic circuit creation (to replace Eagle). Any ideas?

ya.. a slayer christmas

Awsum chirstmas lights display

More vibs

I'm still looking for a good funk vib solo, but till then more good jazz..

Vibs

People have been confused as to what a vibraphone is: here is a good jazz vib.. from Russia..

damn! that is a mud slide.. destroying port in Brazil

via Boing Boing

the Quantitive Easing... this is really f@#ked up!!

no words.. just listen..

Mini airplane models

this is a great video of some mini airplanes being flown in a gymnasium in Japan.. The flying angle was unstable.. but funny none the less...