During the Siege of Syracuse in 214-212 BC, Archimedes used a heat ray to set enemy ships on fire. In “The War of the Worlds” by H.G. Wells, Martians used a Heat-Ray against earthlings. Now, two scientists have built a do-it-yourself solar-powered heat ray from common garage materials that can melt metals. Would it impress Archimedes or H.G. Wells?
Kevin Moore and Grant Reynolds of the Science Channel built their heat ray – or “death ray” as they like to call it - with a Fresnel lens. It’s a magnifying lens that would actually be found in garages in England because it’s used to enlarge TV and video screens and in magnifying mirrors on automobiles.
The wooden stand they built to hold the Fresnel lens pivoted so the lens could be positioned to catch the sun’s rays and focus them to a pinpoint on a stone block where they put objects to be destroyed by their death ray. This is the same concept used by children when they hold a magnifying glass and burn holes in paper or set ants on fire (not me).
Did it work? The Moore-Reynolds death ray was able to and burn a hole in an aluminum packet of popcorn and pop some kernels, meaning it had reached a temperature of at least 660°C (1,220°F). It did not melt a piece of silicon bronze, which has a melting point of 850°C (1,500°F).
Would Archimedes have been impressed? Hardly. His heat ray was said to have set Roman ships on fire by focusing sunlight on them and some recent attempts to duplicate it have been successful under ideal conditions.
Would H. G. Wells be impressed? Not likely. Here’s what the Martian Heat-Ray could do:
Whatever is combustible flashes into flame at its touch, lead runs like water, it softens iron, cracks and melts glass, and when it falls upon water, incontinently that explodes into steam.
Then again, Wells does not say if the Martians’ Heat-Ray was a do-it-yourself device made from stuff lying around a spaceship garage.