Yet another story that features the physics of invisibility, continuing my series of posts inspired by the research into my upcoming book on the history of invisibility physics!

A secret race of mutant humans, gifted with superpowers, hides out from the bulk of humanity that hates and fears them and seeks to exterminate them utterly.

If this sounds familiar, you might be thinking of the classic Marvel comics series X-Men, but in this case I’m referring to the much earlier novel by A.E. van Vogt, Slan, first published in serial form in 1940 and then made into a book in 1946. (Image from the contemporary edition that I read.)

Slan is a classic of science fiction, and A.E. van Vogt’s first novel. Like many serialized stories of the time, it is a fast-paced tale with lots of twists and turns (and things that don’t completely makes sense if you…