A 12-year-old has built a replica of Archimedes' death rays - and it works! - Walla! news. Brendan Senner Proved that the ancient death ray worked.
He used a series of concave mirrors and LED lamps to focus a 50-watt heat source on a piece of cardboard. When he repeated the experiment using a 100 watt lamp, he found that the temperature with each mirror was up to 4°C. He then used a fourth mirror to increase the temperature by up to 10°C - and an additional 10 additional reflectors were used to focus the beam of light.