That the gentleman in question was a nut was beyond question. He was an institutionalized psychotic. He was nutty enough to think he could make an atom bomb out of modeling clay!
You're all alone in a deserted city. You walk down an empty street, yearning for the sight of one living face--one moving figure. Then you see a man on a corner and you know your terror has only begun.
Consider the poor mailman of the future. To "sleet and snow and dead of night"--things that must not keep him from his appointed rounds--will be added, sub-zero void, meteors, and planets that won't stay put. Maybe he'll decide that for six cents an ounce it just ain't worth it.
The conversion of light into electricity by spectrum is an interesting possibility. The idea of using foreign proteins on the human system to repel enemies, is also interesting. Do you get it? We didn't either until we read the story. Read the yarn and you'll get it too.