The best armor, if it could be devised, would weigh absolutely nothing. It would surround its wearer in an impenetrable aura of pure protection, holding all threats at bay. This idealized defensive system could come in the form of a force field, and it would be useful for stopping everything from nuclear missiles to small drones. With directed energy weapons, the Air Force believes such a force field is someday possible—but that day is in 2060 at best.

References to force fields appear three times in “Directed Energy Futures 2060,” a report from the Air Force Research Laboratory published July 16. The potential for military force fields is captivating—a concept that seems more suited to science fiction; the report actually contains an appendix of three science fiction vignettes.

The real-world term to know here is “directed energy,” and force fields are one of the more distant applications of that idea.

As defined by the report, “directed energy” is any focused beam of electro-magnetic energy used for a military purpose. This can be the burning destruction of a drone from a high powered laser, jamming radio frequencies, or it can even be as simple as using a low-powered laser to illuminate a target for a laser-guidance system.

(Via PopSci.)

Science fiction authors have, of course, been fascinated with the idea for generations. The term itself dates from at least 1931; see the article on force field from Islands of Space, by John W. Campbell and published by Amazing Stories.

Even before the term was invented, science fiction authors described the idea. For example, in his 1929 story The Onslaught from Venus, Frank Phillips described a "fan ray":

By now, however, the invaders’ machines that looked like searchlights got into action. They spread fan-like beams of iridescence overhead These beams the operators quickly wove into an interlocking network, making virtually a continuous cone of pulsing light, its base the circle on which the machines had been set up, and its apex about a thousand feet in the air.

The planes of the Air Guard returned to the attack, this time dropping bombs as they passed overhead. I broke into a cold sweat. I knew the power of those bombs, and figured my life in terms of split seconds.

Then an amazing thing happened. The downrushing bombs bounced off the cone-curtain of light as though from an invisible rubber wall, and exploded harmlessly. Not even the fragments showered around, for these too bounced off in their turn.

(Fan Rays from 'The Onslaught From Venus' by Frank Phillips)

[The column of soldiers was winding its way across the plain in the direction of the beleaguered fortress. In the center marched the infantry and on either side a column of fan«ray machines on lever-like legs spread a fan of rays over the soldiers.]

(Read more about fan rays)