Nice! Reminds me of this very relaxing video:

http://vimeo.com/9498805

For context, Both Max and Marcus were studying at the Royal College of Art in London at the time. Not sure about the stool, but the Solar Sinter was Marcus' graduation project, and it was quite a hit when it went public.

Exactly what I thought I'd see.

What's more interesting is how much energy there is in just that screen's surface area of sunlight. Enough to turn sand molten in under a second. Thinking of just how far away that is from the sun, and how much more surface area there is in a sphere with a radius that size..

A laser of 20-100 Watt is enough for Selected Laser Sintering.

So a square meter lens for the sun will give you more than ten times the power professional SLS printers are using.

That is indeed a lot.

Edit: here a nice answer about the heat generated: http://physics.stackexchange.com/a/103039

I believe you can get around a kilowatt per square meter, obviously depending on latitude, weather, and other factors. That lens looks about like a square meter.

*Kilowatt/m^2

Yeah, that's the prefix I was looking for.

This is really cool, although leaving that size of fresnel lens uncovered makes me nervous.