You will have picked up on my absolute dismay at the moronic articles written in the media nowadays.
The above picture came with the heading:
"Teen's 'Solar Death Ray' can melt concrete".
This is just a bigger version of small boys tormenting ants with a magnifying glass.
Yes, if you use 5800 small mirrors to focus the sun, you will get a pretty hot spot at the focal point. But not a ray, as we know it Toto.
Here is a bigger version, build in France in 1970:
And here's a cute little cooker that you can take on your next camp:
It they expect me to pay for news on line, they will have to research things a little better than just calling a parabolic mirror a 'death-ray'.