Aprender toda a vida!

Mais disto, no fim, do Post, hé, hé:

A Electricidade Estática, estudada desde a Grécia Antiga, não é assim tão estática!

Há mesmo, uma ínfima TRANSFERÊNCIA DE MATÉRIA!

After Thousands of Years of Research, We're Still Trying to Figure Out Static Electricity

By Clay Dillow

Today in the Things We Thought We Understood But Really Don’t file, a Northwestern University researcher has upended what was previously thought to be a pretty good understanding of how static electricity works. Static electricity goes beyond the usual theory that it's a simple imbalance of charges caused by the exchange of ions, the researchers’ paper says. Rather, it is the result of an actual transfer of material.

Static electricity has been under investigation for a few millennia now, with research dating back to the ancient Greeks. But the Northwestern team wasn’t convinced that everything was as it seemed. So they applied Kelvin probe force microscopy to the problem, which allowed them to see the varying levels of charge distributed unevenly across the surface of objects.

http://www.popsci.com/science/article/2011-06/after-thousands-years-research-were-still-trying-figure-out-static-electricity

Para quem ainda pense que não se encontra de tudo na Net, um Programa para desenhar Lentes Fresnel, as dos Faróis que vêem na Costa, duma série de apps para Desenho de Sistemas de Óptica:

How to Model a Complex Fresnel Lens
By Mark Nicholson

The Annular Aspheric Lens Object

For situations where precise control of the Fresnel is needed on a ring by ring basis, the Annular Aspheric Lens Object is ideal:

This object has the surface shape of an even aspheric surface (radius, conic, and even-polynomial aspheric coefficients up to r16) on both faces, plus user-definable maximum and minimum diameters and thickness. It is ideal for modeling complex Fresnel lenses.

http://www.zemax.com/kb/articles/174/2/How-to-Model-a-Complex-Fresnel-Lens/Page2.html

Hem? Isto é que é Serviço!

E cá temos... A Elastomatik, à venda!

Elastic Band Gun: New Project Released!

Jon

This great elastic band gun projects is brought to you by Edgar the Inventor and although it’s geared more for acrylic, using 3mm thick materials, I’ve released it on WoodMarvels.com anyhow. If it works in acrylic, surely, it will work in wood as well though thicknesses may be an issue (finding 3mm thick wood that is).

You can find this project right now on WoodMarvels.com under Collaborations / Edgar the Inventor. You will want to get the assembly instructions (without plans) for this project if you get the EPS file – this project is tricky.

http://blog.woodmarvels.com/elastic-band-gun-new-project-released