Nor will we find gods, goblins, angels, fairies or ghouls lurking at the bottom of the garden
We humans have a hardwired set of neural patterns that, without us realizing it, influence the way we perceive the world and the fantasies we conjure up. That’s why all religious mythologies are fundamentally the same: mummy or daddy god creates the world, shoves animals etc. into it, there’s a clash between positive and negative, and there are some crude tenets for how to live the “good” life. Polytheistic myths are usually more psychologically adequate than monotheistic myths, and thus less harmful, but all are essentially trite and tedious because of their intellectual vacuity.
Another hardwired pattern is our frame of reference: the group. Throughout our evolutionary history, small groups of humans would encounter other groups of humans, very often to fight over precious resources; less often to engage in mutually beneficial trade. We naturally think of our group as our reference-point and other groups as “strangers.”
As the baroque superstructure of religious mythologies grew after the development of agriculture and the consequent emergence of large-scale human populations anchored to a single location, the “stranger” was often symbolized within the context of prevailing mythology. Those following the Vedas might see an incarnation of one of the many gods, come down to Earth and recognizable by his ability to manifest vibhutti in the palms of his hands. Others, under the influence of Christian mythology, would see angels or saints appear before them. Meanwhile in lands where Norse myths clung on, people would worry about trolls living under rocks or in the hollows of rotted-out trees. And we’ve all heard about fairies and elves, which not so long ago people would also see on a regular basis.
Today, science fiction ensures that more people believe in space aliens than in fairies or goblins. Many believe the Earth is visited regularly by alien spacecraft and not a few Americans fondly imagine they’ve been on the receiving end of a rectal probe. The myth of the “stranger” has merely morphed under the influence of our technological world, but is no more real than angels or ghouls.
Although people will continue to speculate endlessly about little green non-gender-specific aliens and some who ought to know better will create equations that claim to show why intelligent technological civilizations must be tripping over themselves wherever we point our telescopes, a few simple facts serve to rule out any intersection between our species and any other technological species elsewhere.
First of all, let’s consider distance. Let’s not even think about the universe but restrict ourselves to our home galaxy, the Milky Way. This is 105,000 light-years across. As light travels at approximately 300,000 kilometers per second, that means a single light-year is 9,460,800,000,000 kilometers. To put this in perspective the dwarf planet Pluto is only 5,215,000,000 kilometers away, or less than 0.055% of a light-year.
Now the very nearest star to us is Alpha Centauri, 4.22 light years away. It doesn’t appear to have any planets that could give rise to life. But even if it did, it’s a long, long way away. If we could somehow build a craft that could travel at 5% of the speed of light (and that’s a huge if, because a phenomenal amount of energy would be required to accelerate a spaceship-sized mass to that speed) it would take slightly over 120 years to make a one-way trip assuming a gradual acceleration and deceleration in order to avoid turning any living crew members into pulp.
So why would any life-form embark on a 120-year one-way trip, even if it had found ways to prolong its lifespan, or had invented whizzy cryogenic technology? What would be the point, when the technologies required to send robotic missions would be faster, easier, cheaper, and infinitely more effective?
Unfortunately for Star Trek enthusiasts, things get worse from there on out. Realistically, the number of planets that could potentially give rise to some technological alien civilization are extremely few even on the best-possible assumptions. So instead of journey times measured in centuries we’re talking about journey times measured in thousands of years. Which makes it all rather implausible.
Eager sci-fi enthusiasts will claim that we’ll use wormholes or Alcubierre drives or perhaps magical incantations spoken over a brew of herbs and bat’s tongues. But none of these notions are in fact credible. The math governing Einstein-Rosen bridges (the so-called wormhole) connecting two entangled black holes shows that the bridge grows faster than light can traverse it. In short, you could go in but you’d never come out. And that would be if you could (i) work out how to create two entangles black holes, and (ii) move one to where you want the destination to be, and (iii) not be torn apart by tidal forces as you approached the black hole’s event horizon. All of which are, as physicists say, “non-trivial” problems.
As for the Alcubierre drive, once we’ve stopped laughing at the idea of consuming a Jupiter-sized mass every few seconds in order to power our magical device, there’s the tiny problem of finding a way to keep the occupants of the craft from being crushed out of existence, not to mention the fact that warping spacetime is actually a very slow way to get around. That’s why black holes sit in the center of galaxies rather than going on day-trips to visit their friends elsewhere.
So assuming we retain the power of coherent reasoning, it is pretty obvious that the sheer distance between things makes it vanishingly unlikely any technological civilization will “boldly go” anywhere except perhaps the planets of its own solar system — and even then, why bother when robotic missions will always be cheaper, better, and faster? Furthermore, robotic missions won’t expose crews to the horrors of constant radiation, zero-G effects on physiology, and a host of other bad things that happen when you put creatures evolved to live on a planet into the very different environment of space. And sure, we can pretend we’ll invent artificial gravity and radiation shields and everything else required to make space a little less hostile to life, but this adds to the energy required to move our imaginary spaceship around, and so creates yet another big challenge. In real life there are no magical dilithium crystals we can use to scriptwrite our way around the problem.
Now we can add to the problem of distance the problem of time. Our civilization only reached a level of technology capable of rudimentary space travel and observation a few decades ago. It’s not implausible to imagine us wiping ourselves out at some point in the next couple of hundred years and pushing humanity back into the days of pointed sticks and napped flints for a few millennia. Even if we manage to avoid catastrophic self-harm, we’d have to be astonishingly lucky to over-lap another technological civilization. Imagine if a civilization just 50 light-years from Earth came into existence a mere million years ago: at that time our ancestors were grunting and throwing stones at each other. And a million years is the blink of an eye in cosmic terms.
Sci-fi enthusiasts like to imagine we’ll develop all manner of magical life-extension tricks and games, so that we can cheat evolution and persist for millions of years. But why stop there? Why not imagine we grow wings and fly away? Or (and I admit this is vanishingly unlikely) become more intelligent and stop doing stupid stuff? If we’re going to play “let’s pretend” there’s no limit to the fantasies we can conjure up. Likewise we can imagine aliens so advanced that they’ve morphed with machines and become eternal. But now aren’t we merely back to the gods of yore? And why would such advanced creatures be interested in any interaction with a bunch of tiny-brained apes? Would we expend truly phenomenal resources just to say “hi” to an amoeba? Chances are, any such advanced civilization would have far better things to do.
So there are likely all manner of technologies that will be invented in the years ahead, and who’s to say if a technological alien civilization might not invent their own whizzy stuff we haven’t dreamed of yet. But the hard limits of physics won’t vanish merely because we’d like them to. When we make the effort to actually understand the math, it turns out that quantum teleportation and wormholes and all the rest of our repertoire of sci-fi magic turn out to be infeasible in principle as enablers of galaxy-spanning activities. Which doesn’t matter for Hollywood scriptwriters but does matter for real life endeavors.
When we mix both distance and time into any reasonable equation we come up with one inescapable conclusion: there is a near-zero probability of any two technological civilizations overlapping in time and being physically proximate enough to one another to permit the exchange of communication signals. Even a civilization a mere 60 light-years away would mean we’d have to wait 120 years between send and receive. Even if we were smart enough to send a signal that was comprehensible, which so far we’ve abjectly failed to do.
So we can relax and stop worrying about being invaded by bug-eyed aliens, just as we’ve stopped worrying about being abducted by trolls or turned into trees by irritated deities. We desperately need to focus on mitigating the massive real-life damage we’re inflicting on the only planet we’re actually evolved to inhabit instead of wasting time frightening ourselves with children’s stories about nasty aliens. Baba Yaga isn’t real and nor is ET.
We have better things to do with our imagination.