Among people who think about intelligent alien life, the first question is whether the latter exist at all, and the second is usually “What do they look like?” People who claim to have seen aliens on Earth (and often, to have been abducted by them) usually say they are humanoid, but with considerable variation in other aspects of their appearance. Typically, the aliens are said to have larger heads than humans, meaning their brains are larger, giving them higher intelligence and perhaps even special mental abilities like telepathy. Hollywood has provided us with an even more diverse envisagement of alien life, from the beautiful and inspiring to the grotesque and terrifying.
I think intelligent aliens exist, and look like all of those things, and nothing in particular. They’re probably “shapeshifters,” either because their bodies can morph into different configurations, or because they can transplant their minds from one body to another, just like you change outfits.
As the multitude of animal species on our planet demonstrates, there is no single “best” type of body to have. Depending on your environment (terrestrial, underwater, airborne), role (predator, herbivore, parasite), and other factors, your optimal body plan will vary greatly. The best species is thus one that can change its form and function in response to the needs of the moment.
Humans have been so successful as a species because our big brains and opposable thumbs give us the ability to create technology, which is a way around the limitations of our fixed anatomy. For example, we originated in Africa where it was hot, and so lacked thick fur to keep us warm in cold climates. Rather than being stuck in Africa forever, we invented clothing, and so gained the ability to spread to the temperate and polar regions of the planet.
Our technology has let us spread, but its has limitations. Nothing but a fundamental alteration of human biology will let us live in oceans and lakes, to fly naturally, or to live comfortably in extraterrestrial environments. For example, on other planets and moons, our ideal heights and limb proportions will vary based on gravity and temperature levels, and in the weightlessness of space, legs are almost useless and should be replaced with a second pair of arms.
And making any of those changes to tailor a human to such an environment would make them less suited for conditions on Earth’s land surface, where we are now. Biology is very constraining.
For those reasons, AI’s and some fraction of our human descendants, who I’ll call “posthumans” for this essay, will find it optimal to not have fixed bodies or “default” physical forms at all. Intelligent machines will exist as consciousnesses running on computer servers, and posthumans as brains inside sealed containers. Those containers will have integral machinery to support the biological needs of the brains, and to interface the organ with other devices.
Whenever the AIs or posthumans wanted to do something in the physical world, they would take temporary control of a body or piece of machinery that was best suited for the intended task. For example, if an AI wanted to work at an iron mine, it would assume control over one of the dump trucks at the site that moves around rocks. The AI would see through the truck’s cameras as if it were its own eyes, and hear its surroundings through the vehicle’s microphones. In a sense, the dump truck would become the AI’s “body.” If a posthuman wanted to experience what it was like to be an elephant, it would take control of a real-looking robot elephant whose central computer was compatible with the posthuman’s cybernetic brain implants. The posthuman’s nervous system would be connected to the artificial elephant’s sensors, effectively turning it into the posthuman’s temporary body.
AIs and posthumans could physically implant their minds into those bodies by inserting their servers or brain containers into corresponding slots in the bodies, in the same way you would put a movie disc into a Blu-Ray player to display that movie. The downsides of this are 1) they could only take over larger bodies that had enough internal space for their servers/brain containers and 2) they would put themselves at risk of death if the commandeered bodies got damaged.
A much better option would be for AIs and posthumans to keep their mind substrates in safe locations, and to remotely control whatever bodies they wanted. Your risk of death is very low if your brain is in a bulletproof jar, in a locked room, in an underground bunker. (Additionally, if posthumans were liberated from all the physical constraints of human skulls and bodies, their brains could grow much larger than our own, giving them higher intelligence and other enhanced abilities.)
Finally, being able to switch bodies and to indulge in risky activities without fear of death would make life richer and more satisfying in every way. Intelligent aliens would presumably be gifted with logical thinking just as we are, and they would see all these advantages of having changeable, remotely controlled bodies. While such aliens would probably look very different from us during their natural organic phase of existence, once they achieved a high enough level of technology, they wouldn’t have physical bodies anymore, and so wouldn’t look “alien.” They would look like nothing and everything.
This part of why I’m skeptical of people who claim to have been abducted by aliens who tried to cover up their actions by sneaking up on the people at night and then “wiping” the abductees’ memories of the event afterward. If aliens wanted to keep their activities secret, why wouldn’t they temporarily assume human form before abducting people? If they did that, then the abductees would assume they had been kidnapped by a weird cult or maybe a secret government group. Their stories would not attract nearly as much interest from the public as alien stories, and no one would suspect that the abduction phenomenon was related to alien life. It would be assumed that the henchmen were doing some dark religious rituals, were sex fetishists, or were doing medical experiments that were illegal but whose results were potentially valuable.
Surely, if aliens are advanced enough to travel between the stars, their space ships much have manufacturing machines that can scan life forms they encounter on other planets and then build robotic copies of them that the aliens can remotely control from the safety of their ships. Using fake human drones, they could ambush and abduct real humans almost anywhere without risk that anyone would suspect aliens were involved.
This belief about the protean nature of advanced aliens is comforting since it lets me dismiss the stories of nightmarish abductions by grey aliens. However, it’s also disquieting since it makes me realize they could be here, possibly in large numbers, disguised as animals or even as people. We could be under mass surveillance.