Weird science

Horror often entwines with science fiction very nearly in a double helix arrangement, as if part of its life. The relationship makes sense. There never was an era when science appeared to be only a positive, illuminating force sweeping aside all shadows. Beside the brilliant Dr. Jekyll there always has lurked the dark presence of Mr. Hyde — a sense that our amazing inventions carry our doom, and that we discern the universe with increasing accuracy only to discover it has no sympathy for us. Science tells us even the most basic facts about our world are not actually facts, but are only a provisional consensus we should be prepared to discard. That is freeing and wonderful, of course. But there is no shortage of horror in it.

The horror/science fiction DNA goes back a long way. Take Frankenstein by Mary Shelley (1818), illustrated here by Bernie Wrightson (1980).

Today’s story, “Alien,” is a strand somewhere within this double helix. I feel real horror about the monster in this one — but the horror only works to the extent that the science elements make it believable. So it was important to get them right.

In truth, the story makes only one demand of its extraterrestrials: They must see by a wavelength invisible to us, and be blind to the light we see.

Originally I wrote the E.T.s as stout, shambling things with dense skulls, from a massive planet. But in taking up a second draft, I conducted my research, and it turned out the only wavelength that could give them the vision the story needs is ultraviolet. Which is emitted only at extremely high temperatures (our sun emits some, a lamp or campfire does not). For my scheme to work, their world would have to orbit a sun much hotter and brighter than our sun — so searingly bright, in fact, that in defense against it, I decided, their eyes evolved to ignore its punishing “visible” spectrum, and instead perceive its more moderate UV radiation.

All right, that was easy enough. . .

But atmosphere screens out UV, meaning these E.T.s must have evolved in air thinner than ours. Thinner atmosphere likely also means a smaller planet, which means lower gravity, which means thinner bones and builds. Which would additionally be well-suited to a planet with temperatures high enough to make liquid water scarce, therefore food scarce; life forms there would be lighter, to require fewer calories. And to stay high-energy in the heat, they’d have thinner blood, which also would be more brown, like rust, because it needs higher iron content to bond more efficiently with oxygen and create energy.

And because my E.T.s are from a hot world, with bodies that have no reason to retain warmth, now I had a reason to install a lot of heaters on the space ship — neatly lending my relentless killer his light source. (You might imagine the E.T.s will figure out how he’s seeing in the last 20 minutes of the movie, and shut the heaters off — risking death by cold to blind him and equalize the fight. How exciting. . .)

Giant E.T. skull found on the atmospheric Planet of the Vampires (1965).

And so my space travelers became stout shamblers no more. Good-bye, dense skulls. But how else to describe them — what did I know about them? Well, with lower elevations scorching on their planet, they’d probably begun high in the mountains — where the weather is a balmy 90 to 120 F, like our Death Valley. And up there, they’d develop legs for climbing, with bodies broad rather than potbellied, adept at pancaking close to the cliffside to stay put when the wind picks up.

An interesting origin — they might not be apex predators at all, but apex survivors.

And that’s how they evolved from the first draft into what you find here, all because I needed their eyes to see differently. I will say one more thing — which is that I made them green, as extraterrestrial life forms often are. But when Steve got a look at the story, he wrote to me to point out that in the orange light of the heating elements, green would not read. A very scientific point! So I dropped that detail. Yet another case in which, thanks to science, we now know less.