OK, this is just cool:
For those unfamiliar with a Fresnel (fray-nel) lens, it’s a flat surface with a series of concentric circular ridges. Basically, since it’s the outermost part of a lens that does the most focusing, this is like combining hundreds (maybe thousands in this case) of “traditional” lenses.
So what do you do with a giant Fresnel lens? Anyone who ever cooked ants and started paper fires with a magnifying glass knows the answer to that question:
When I carried the lens out of the garage, I knew we were in for a good show. The asphalt driveway started smoking. Our first target was a penny which the lens quickly melted into slag. Next up was a hamburger. We widened the focus and it flash cooked the top of the burger.
I gotta get me one of these. 😉