1) Solar energy 2) Weapon of mass destruction
Found on
https://www.crosswordclues.com/clue/sun-gun
The sun gun or heliobeam was a theoretical orbital weapon that was researched by Nazi Germany during World War II. ==History== In 1929, the German physicist Hermann Oberth developed plans for a space station from which a 100 metre-wide concave mirror could be used to reflect sunlight onto a concentrated point on the earth. Later during World War I...
Found on
http://en.wikipedia.org/wiki/Sun_gun
No exact match found.
