The Ultimate Weapon by John W. Campbell

 

 

The star Mira was unpredictably variable. Sometimes it was blazing, brilliant and hot. Other times it was oddly dim, cool, shedding little warmth on its many planets. Gresth Gkae, leader of the Mirans, was seeking a better star, one to which his "people" could migrate. That star had to be steady, reliable, with a good planetary system. And in his astronomical searching, he found Sol. With hundreds of ships, each larger than whole Terrestrial spaceports, and traveling faster than the speed of light, the Mirans set out to move in to Solar regions and take over. And on Earth there was nothing which would be capable of beating off this incredible armada-until Buck Kendall stumbled upon THE ULTIMATE WEAPON."

 

John Wood Campbell, Jr.was an influential figure in American science fiction, editor of Astounding Science Fiction and generally credited with shaping Golden Age of Science Fiction. Isaac Asimov called Campbell "the most powerful force in science fiction ever, and for the first ten years of his editorship he dominated the field completely.