Stephen Hawking was recently in the news again with word that he plans to join forces with a Russian billionaire in a search for extraterrestrial life.
This is kind of interesting when you contrast it with Hawking’s past statements about aliens, where he has warned that contacting aliens could lead to humanity’s doom. Still, I suppose you could argue that Hawking isn’t really contradicting himself here. There’s a difference between passively listening for signals from extraterrestrial civilizations and actively trying to contact them — though that distinction is probably lost on much of the general public, which tends to group anything related to extraterrestrial life into the general category of pseudoscientific weirdness. Just ask the pioneering and deeply thoughtful SETI (Search for ExtraTerrestrial Intelligence) researcher Seth Shostak, who spends an inordinate amount of time dealing with cranks who think aliens secretly control the world.
It’s difficult to know what Hawking himself actually believes, since I’ve long suspected he enjoys cultivating a public persona that probably shares little with his actual personality. If you’ve spent much time around people in Hawking’s intellectual league, you know they can be incredibly difficult. They just don’t SEE the world they way you or I do, and can be quite cranky when ordinary mortals fail to see things from their perspective. This can be a problem if you get a reputation as the World’s Smartest Human Being, and are suddenly asked to offer comment on all kinds of problems that are far outside your field of expertise.
Celebrity-scientists like Hawking often end up taking a page from Richard Feynman, creating a cutesy mad scientist act that they trot out whenever they’re called upon to perform in front of a non-scientific audience. Consequently, they end up talking about a lot wacky-sounding ideas in public that they’d probably be more circumspect about in private discussions with their scientific colleagues.
A lot of people don’t know this, though, so they take Hawking’s “warnings” about extraterrestrials seriously. But to me, when “serious” scientists start ruminating about the “dangers” of aliens, it always has the faint odor of bullshit.
Here’s why: As Hawking is surely aware, outer space is mind-bogglingly gigantic. If you’re a kid who grows up interested in sci-fi, this is one of the first, heartbreaking things you learn about outer space: It’s huge. Really huge. If you want an idea of just how huge outer space is, this is a bracing example.
In short, you will never get to be Han Solo, and neither will your children or grandchildren or great-great-great grandchildren, because we will never be able to build ships that can effortlessly traverse the vast gulf of space — at least not any time within the foreseeable future. Even if you look at the most radical, pipe-dream ideas for spaceships that scientists and engineers have managed to cook up, the ones that remain generally within the realm of scientific plausibility would still be painfully slow for the purposes of interstellar travel.
Assuming our current understanding of physics is reasonably correct, interstellar travel would have to be monumentally difficult. Any species that can solve the problems of interstellar travel within the bounds of our current knowledge will probably be ahead of us technologically by at least a few centuries — probably a lot more. They will have successfully solved a number of thorny scientific problems that our species has barely even begun to understand, and they will be able to solve them with enough rigor to reduce them to the level of textbook engineering tasks.
Having established this, one must ask: What could such a hypothetical species want from us?
“Resources,” you might say. Well, consider this: Our solar system alone contains more resources than humanity could possibly consume. Even if the human population were so large that we drove every other form of animal and plant life extinct, and humans covered every square inch of habitable land on the planet, we wouldn’t even make a dent in the solar system. It would be close to a mathematical impossibility for the population of our planet to exhaust the total resources contained just within the eight official planets of our solar system, along with their accompanying satellites and the odd asteroid or stray comet. Other solar systems are undoubtedly similar. We will hit the limits of living space long before we hit the limits of resources that are within reach of just our current generation of spacecraft.
And here’s why that’s important: If you possess the technology to easily travel from Earth to Alpha Centauri, then traveling back and forth between Earth and, say, the moons of Jupiter ought to be a piece of cake. If traveling to another star is like Columbus’s voyage to America, traveling to the moon is roughly analogous to paddling across a pond in a canoe. A very small pond.
A species that has mastered interstellar travel effectively has access to limitless resources that could be easily tapped without needing to take over a tiny, insignificant planet such as ours. The idea of an advanced alien species attacking us to acquire our resources makes about as much sense as the U.S. sending out a carrier battle fleet, a division of Marines, and a B-52 bomber wing to steal coconuts from a primitive jungle tribe on a tiny island in the Pacific.
Well, maybe the aliens have mastered resource extraction, you say. But maybe they’ve got a booming population, so they covet our planet’s real estate. What they really want from us is elbow room. How about that?
Again, it doesn’t really add up. With an entire galaxy or universe to choose from, why pick us? Why not choose a planet with no higher forms of intelligent life to displace? And again: We’re talking about a race that has mastered interstellar travel. Terraforming dead alien worlds to make them habitable should be well within their capabilities.
To be sure, my account here depends upon a whole nest of assumptions which may or may not be correct. But the assumptions I’m making are generally the most conservative ones — at least, based on the admittedly-limited example of our own planet.
I assume, for example, that our planet is an example of convergent evolution, and that if life evolves on other planets, it will resemble life here on earth. On our own planet, we have the example of Australia — cut off from the rest of the world for millions of years, life there evolved into a variety of species that, morphologically, turned out to be strikingly similar to species elsewhere. I presume alien life would follow a pretty similar path. Maybe this is just my heritage showing, seeing as I’m the son of an engineer, but I assume that for any real-world problem, there are a finite number of optimal solutions, and that anywhere those problems arise, the ultimate solutions will end up being drawn from the same limited basket.
Based on the limited extrapolation we can draw from planet earth, I don’t think extraterrestrial contact is necessarily impossible. I think, rather, that any aliens taking the time to contact our tiny planet will have something larger in mind. Back in 2005, when he was promoting “War of the Worlds,” somebody asked Steven Spielberg about aliens. I don’t remember his exact words, but he basically said he thought any aliens who’d bother to travel to planet earth would come here primarily as missionaries — they’d arrive here carrying whatever was their version of the Bible. The only thing he could imagine that would motivate them to go through all that trouble to come here and communicate with us would be some sort of mystical text with a message they considered so important that every intelligent form of life in the universe needed to hear it.
Maybe this is just my Southern Baptist upbringing showing through, but I think that’s 100 percent correct. If humans ever land on another planet with intelligent life, you can be almost certain that one of the first people to step onto that alien world will be carrying some version of the Bible, the Torah, or the Koran.
It’s possible, of course, that this could turn out to be an astoundingly blinkered point of view. Aliens could turn out to be, well, alien in the truest sense of the word. They might be so different from us that we might not even be able to recognize them as a form of life, and vice versa. For example, I’m making what I consider to be the extremely conservative assumption that any life anywhere in the universe will at least have its roots (emphasis important) in carbon-based compounds using water as a solvent. It’s possible, of course, that “life” could arise from alternate biochemical frameworks, in which case other forms of life might turn out to have an understanding of reality completely incompatible with our own.
A related speculation is that “aliens” might be intelligent machines. (Intelligent computers, though based in silicon, might have their “roots” in carbon-based life, hence my qualification in the above paragraph.) This changes the reasoning I outlined above about interstellar travel, which is based on ideas about human, or at least human-like lifespans: Sufficiently advanced computers would presumably not face these limitations. They would be able to plan and reason far beyond time horizons familiar to human beings.
Machines might make decisions that look utterly insane to us merely because they’re looking at things from a far longer perspective than we are capable of. They’re already thinking 5,000 years ahead; a decision that seems patently illogical within our time horizon might look perfectly rational within theirs. There have already been tantalizing hints of this sort of thing from artificial intelligence research.
Take chess, for example, where inexperienced players can sometimes be flummoxed by a chess program’s early-game maneuvering. In chess, a computer can run through thousands of alternate scenarios in the time it takes for a person to reach out and move a piece from one square to another. The only reason that computers don’t consistently beat humans in chess is because chess remains a mathematically unsolved game, and the human brain still beats computers in such arcane realms as pattern recognition, a kind of “cheat code” which allows humans to see beyond the mathematical horizons of (current) machines. Even so: In games pitting humans against computers, one occasionally finds that decisions that seem incomprehensible to humans turn out to be perfectly rational when viewed on a scale much longer than human minds can profitably anticipate.
But here’s the problem with either of the scenarios I outlined above: In either case, it’s hard to see how Hawking’s “warnings” about “alerting” alien civilizations to our presence could do any good. Hawking’s “warning” is based entirely on the assumption that this hypothetical extraterrestrial civilization would be roughly similar to our own — just with access to some imagined super-technology that allows them to zip effortlessly across the universe. Robots or aliens with alternate biochemistries are not dangers we could realistically guard against, especially considering the fact that intelligent life on earth already has a (conservatively speaking) 100+ year-long electromagnetic signature drifting out there through the cosmos.
So, to sum up: I think Hawking’s past “warnings” about alerting extraterrestrials to our existence is a bunch of horseshit aimed at the peanut gallery. Stephen Hawking is much, much, MUCH smarter than I am, so all of this stuff has almost certainly occurred to him; he is basically just talking out of his ass. The truth is that any hypothetical alien civilization we might hear from will probably fit into one of two categories:
- A civilization far superior to our own. They would be a source of exciting new insights about science. In this case, the aliens will almost certainly have detected us long before we manage to detect them. I suspect this is probably what Hawking believes, and is hoping for. He would like aliens to be able to succinctly explain the solutions to problems he’s been mulling over his entire life. Or, on the other hand,
- A civilization somewhat similar to our own. It’s likely that the first signals we would pick up from these aliens would be their version of “I Love Lucy.” In this case, anything resembling real-time communication will be impossible. Even if you assume laser-based communication (the most likely scenario for any alien civilization actively trying to communicate with us), you’re still probably talking about decades of time between messages. This is a fascinating idea which I’ve seen explored in science-fiction literature, but it’s kind of boring from the standpoint of actual people — you send a message into outer space, and then your great-great-grandchildren get the response. Who can get excited about that?
There are a couple of other possibilities I can think of.
The first: Perhaps there is some sort of “shortcut” in physics that would allow easy traversal of huge interstellar distances. This idea, naturally, is at the root of a lot of popular sci-fi — it’s pretty boring if you send your characters out on a mission that, realistically, can only be completed by their great-great-great-great-great grandchildren. (Not that some writers haven’t tried — they have, and there have been some terrific books using this idea as a starting point — it’s just not a narrative likely to have mass appeal.)
But while the idea of a physics-based “shortcut” for interstellar travel is wildly appealing for sci-fi aficionados, but I don’t think Hawking really believes this is possible. My evidence? Well, in 2009, Hawking jokingly held a party for time travelers, which no time travelers showed up for. Now, the Standard Model of physics does not explicitly rule out the possibility of time travel, but many, many, many physicists (including Hawking) still firmly believe that time travel is utterly impossible, and that future scientific discoveries will establish this beyond a shadow of a doubt.
Supersession of light speed under controlled parameters — a must for interstellar travel on any scale humans can realistically anticipate — is probably more outlandish than time travel for Stephen Hawking; at least time travel doesn’t explicitly breach the known laws of physics. If Hawking doesn’t think time travel is real, I doubt he believes faster-than-light travel is possible.
The second possibility: Our universe — or to be more paranoid about it, your universe — is a computer simulation.
This isn’t directly anticipated by Hawking’s speculations, but it DOES manage to clear up a lot of weird, messy issues about our existence. For example: If you assume that the development of intelligent life, and a civilization capable of reaching out to the stars through electromagnetic signals, is inevitable, there is the problem of explaining the utter silence of the universe as we humans experience it. Even if one adopts a fairly conservative estimation about the likelihood of intelligent life developing on other, extrasolar planets, shouldn’t the universe be FILLED with signals from alien civilizations? Why does the universe seem so “silent” in that regard?”
If, on the other hand, one assumes that the rest of the “universe” as we perceive it is basically “wallpaper” — to put it in human terms, it’s God’s giant screensaver, while He’s away from his “computer” working on something else — well then, that makes perfect sense. Laugh all you want, but there are people who have seriously proposed this sort of thing.
It’s not an entirely insane idea. Here’s something I read about recently. Try this: Go up to a random person on the street and ask them a really strange, off-the-wall question. Then watch closely how they respond.
More often than not, they’ll pause a second or two before they provide an answer — any answer. And more often than not, the answer they eventually provide will be fairly uncontroversial and predictable.
Why is that? Well, the ultra-paranoid explanation is that they’re actually a computer simulation. They need a brief moment to respond to a strange question because they’re actually downloading some appropriate response from some central computer somewhere. And you can tell it’s a downloaded answer, because it’s almost entirely predictable; it’s the most noncontroversial response you can possibly imagine to whatever weird question you dream up.
A genuine, thoughtful person faced with a bizarre question might have to think about it for a second, obviously — but when they actually thought of a response, they’d usually come up with a really genuine, bizarre answer. They wouldn’t give the most blindingly obvious answer … Right? 🙂
Seriously, though: Aliens. Hawking is lying, because he’s been bought by Big Whatever. We must contact the aliens now, and tell them to show up in their flying saucers and set mankind straight!
It’s important. Peace out. 😉