Sunday, November 18, 2012

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.

Friday, November 16, 2012

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