Though strings to shape the parabola followed by chicken wire and ferro cement covered in foil would probably make a more durable one.
Derision and disbelief are chronic habitual--perhaps even compulsive phenomena on such threads.
Some of us beging to wonder if certain folks are ill when such do not appear soon enough on a UFO thread.
"Though strings to shape the parabola followed by chicken wire and ferro cement covered in foil would probably make a more durable one."
Durable, maybe, but not the most efficient. Hundreds of razor blades stacked next to each other will funnel and absorb much more solar energy. Anything that looks "shiny" is losing too much energy in the direction of your eyeball.