Highly advanced aliens seem MIA, according to a recent study by astronomers at Penn State University. These researchers checked out a huge gob of cosmic real estate — roughly 100,000 galaxies — and failed to find clear evidence for any super-sized alien empires.
At first blush, this is an astounding result, given that the universe is more than 13 billion years old. Surely that’s enough time for at least a few ambitious alien species to establish the type of galactic-wide imperium so beloved by sci-fi fans.
Could it be that no one is out there? Are we now free to declare ourselves the acme of brain power in this part of the cosmos, and certify that everything out to 50 million light-years is Klingon-free?
That may be a bit overmuch. Let’s consider what the Penn State folks really did. In a truly clever piece of work, they used NASA’s WISE (Wide-Field Infrared Survey Explorer) space telescope to measure the infrared light coming from all those galaxies. Infrared is produced by anything warm — by heat.
The second law of thermodynamics mandates that heat is the final product of just about any type of engineered activity. Your auto shoots warm gases out the tailpipe, the local utility plant dumps waste heat in a pond, your TV gets warm… Waste heat is the elephant graveyard of all processes using energy, which is to say, all processes. Even writing a byte of data onto your hard drive produces some heat. So does erasing it.
Now where there’s heat, there’s light (at least of the infrared variety), so the Penn State astronomers were hunting for galaxies that generated far more than the usual amounts of infrared. This could be a tipoff for what’s called a Type III civilization — the black belt of all societies — one that’s corralled the energy resources of an entire galaxy to power the ultra-advanced lifestyles of its residents. All that activity would generate prodigious amounts of waste heat, and that’s what the astronomers sought.
Alas, their hunt failed to discover any interesting cases in which the total amount of heat energy was comparable to the total light energy radiated by all the stars in a galaxy. Bummer.
But hang on. What does that really say?
Allow me to vex you with some numbers. First, consider what the astronomers could have detected. If you add up all the star shine of a typical galaxy, it’s roughly 10 billion times more than is belched out by our Sun, or 4 trillion trillion trillion watts. So the Penn State survey was looking for galaxies producing roughly that amount of energy (or more) in waste heat.
Possibly that number is beyond your everyday experience. But consider what it implies. We now know that a galaxy similar to our own could contain up to 100 billion habitable planets. Even if every one of these worlds is gilded with an advanced civilization, they would each have to be burning up a trillion times as much energy as all of Homo sapiens combined for that galaxy to register in the Penn State survey. That’s right, a trillion times as many kilowatts as all of humanity’s lighting, heating, transport, warfare and other entertainments — per planet.
That’s asking a lot, and obviously these alien super civilizations would have to be much different than our own. Maybe their planets each house a trillion times as many people as Earth, or, at the other extreme, perhaps they have lifestyles that are a trillion times more profligate than ours. Call me timid, but neither seems very reasonable.
The real problem here (if you consider there’s a problem) is that our concept of super civilizations assumes that they have the same mindset that we do; they want what we want. We suppose there’s a law of the universe insisting that advanced societies are always on a colonization binge, taking control of as much of a galaxy as they can — similar to the Galactic Federation or the Imperium of Man. Bigger is better.
But while that view of upscale aliens comports with Darth Vader’s game plan, is that what sophisticated societies really do? There are serious problems with maintaining an empire spanning 100,000 light-years, not least of which is the finite speed of rockets and radio.
In addition, there’s this: In the past few decades, we’ve finally begun to exploit the fact that there’s a lot of benefit to making things smaller rather than bigger (consider your personal electronics). As physicist Richard Feynman once put it when discussing the scale of things, “there’s plenty of room at the bottom.”
Furthermore, we also tend to assume that big-dog extraterrestrials will relentlessly increase their energy use per capita — a number that has long been a proxy for the standard of living in our own society. But maybe what really happens is that technology becomes very efficient, and energy use ceases to steadily climb.
In other words, the view that being highly advanced implies having more stuff gulping more energy might be an anthropocentric aberration.
And by the way, in case the numbers bandied about here have numbed your neocortex, let’s clearly state their implication: the Penn State study has ruled out the existence of a certain type of society. But it hasn’t limited the possibilities for myriad other kinds of extraterrestrial civilizations. Those 100,000 galaxies could be positively stuffed with intelligent beings — be they biological or artificial — who happily exist with energy budgets that aren’t staggeringly extreme.
So it’s still plausible that there’s a lot of cosmic company out there. No, the new observations don’t jibe with what’s portrayed in 21st century space opera. But what our species finds desirable today — 200,000 years after Homo sapiens 1.0 — will undoubtedly seem silly and quaint if we ever reach the point of colonizing the galaxy.Star Wars represents today’s view of the future, not necessarily that of our descendants or of other species.
I recommend maintaining some perspective: The other inhabitants of the universe are alien — which is to say, they’re not like us.
Join our list
Subscribe to our mailing list and get interesting stuff and updates to your email inbox.