Maybe We Haven't Found Aliens Because They're All Asleep
By now you know what the Fermi Paradox is. If the universe is full of extraterrestrial life (and most scientists think it is, with varying definitions of "full"), then why haven't we found any aliens yet? One hypothesis says we're basically exhibits in an intergalactic zoo. When was the last time you wrote a letter to the monkey house's bonobos?
Another theory says we're just too stupid for aliens to bother. Thanks for the vote of confidence, Neil.
But here's a novel idea: what if aliens are out there, but "hibernating" until the universe is more to their liking? Perhaps the truth is out there, but it's taking a nap.
E.T. Enter Sleep Mode
Feeling confused by the idea that one civilization (or several!) could just be taking a galaxy-wide nap? The theory is that it's not so much "sleeping" as it is "power-save mode." That's because the whole thing hinges on aliens having given up their biological form in favor of a purely digital existence. If that's the case, then those computerized beings would greatly benefit from an extremely cold environment. Right now, background radiation has the temperature of outer space hovering somewhere around 3 kelvins above absolute zero — not exactly a sauna. But over the course of trillions of years, that temperature will drop even further, eventually approaching (but never reaching) zero. Once that happens, the digital aliens will basically wake up with super-powers.
Anders Sandberg, Stuart Armstrong, and Milan M. Cirkovic, the authors of the paper, calculated that such a digital civilization would be able to produce 10<sup>30</sup> times as many calculations per second in the near-zero universe than in today's world. That's because every computation has an energy cost, and that cost is closely connected to temperature. With the overall temperature of the universe at an all-time low, these living computers could pull off incredible mental feats for minimal resources.
The only thing is, they'd also be cutting their expected lifespan by trillions of years — why not stay awake and continue to advance while enjoying an ever-more frigid universe? Even Cirkovic thinks the theory isn't necessarily the best explanation. As he told Slate, "I much prefer hypotheses that do not rely on assuming intentional decisions made by extraterrestrial societies. Any assumption is extremely speculative." One thing he does think is likely? That alien civilizations are already digitized.
So what makes a digital civilization so likely, and what would such a civilization look like? Well, what it looks like will depend a lot on how it came to be. It may be, as Dr. Steven Dick theorized in 2006, that biological aliens will eventually upload their consciousness into computers to gain greater intelligence and other benefits. But there are other possibilities. A purely artificial intelligence might also be the biggest brain in the galaxy, whether it was built by biological aliens as a friendly supercomputer or a member of an entirely technological race that long ago broke away from anything organic. That sounds...a little terrifying. Here's hoping they're getting their sleep.