In the scientific community, there is still a great deal of energy devoted to “listening” for evidence or hints of intelligent, extraterrestrial civilizations out among the stars. Most of you are probably familiar with the Search for Extraterrestrial Intelligence (SETI) and their decades of work in this field. They’re still at it and, in fact, are upping their game with a new generation of laser sensors. These projects drew fresh attention after the discovery of Tabby’s Star and the frantic speculation over whether or not some ancient civilization had built a Dyson Sphere around their own sun. This has led one team to train all of their listening sensors directly on the star in hopes of picking up some indication of advanced technology there.
So what is it they’re listening for? Radio waves, for the most part. We’ve been producing them for more than a century ourselves so the traditional thinking is that advanced, potentially space-faring civilizations would as well. But radio wave transmission has a host of problems and challenges which come with it, both for using it ourselves and listening for it from others. First of all, while these waves travel at an impressive clip (the speed of light, actually) that’s still sort of slow in terms of space travel. When we were sending radio commands to New Horizons as it approached the planet Pluto it took 4 hours and 25 minutes for the signal to reach the craft and an equal amount of time for the response to get back to us so we knew if it had worked. That doesn’t exactly allow you to turn on a dime.
Also, since waves propagate outward as well as forward, they weaken over distance. The signal strength coming back from New Horizons was barely above the background static levels. Listening to Tabby’s star means that we’re hoping to “hear” a signal which has been traveling through space for roughly 1,300 years and has faded to nearly nothing.
That’s what got me to thinking about all of these “listening” projects. I’ve been mulling this over for a while now while reading various opinions from experts and, while I find such research projects perpetually exciting, I’ve slowly been coming to the conclusion that there’s one significant downside to all this listening. It’s probably not going to work.
We’ve had technology in the form of being able to at least work metals for barely 3,000 years. That’s a long time in terms of human lifespan, but less than the blink of an eye in galactic or even geological timeframes. We only developed the ability to directly communicate further than line of sight would allow less than two centuries ago. In the relatively short timespan since then, we’ve arrived on the verge of being able to employ faster than light communication using direct counterfactual quantum communication. Using a system such as that, no interception or random discovery of the communications would be possible since you have to be on one end or the other of the conversation. There are no particles or waves being transmitted to intercept and the communications happen instantly no matter how after the participants are.
Despite having come this far in a couple of hundred years, how much further do you think we’d have to advance before we could build a
Dyson Sphere or a ship capable of interstellar travel? If other hypothetical, alien civilizations have mastered such feats, don’t you suppose they’d have figured out quantum communications (or something even more mind-bogglingly advanced) long before now?
The point is, once you are able to conceive of the idea of instantaneous communications over the vastness of space, the idea of sending antiquated old radio waves, laser beams or particle streams of any sort which are clunking along at only the speed of light seems preposterous. If we’re listening for the aliens we suspect might be building Star Wars type empires out there closer to the bustling center of the Milky Way or buzzing our Navy ships when they get bored, we’re probably not going to pick them up because they’re almost certainly using some form of communication beyond our comprehension.
If we are somehow lucky enough to intercept some radio waves from another star which wind up being an interstellar greeting, their version of reality television programming or the latest crossover pop music hit, who do you suppose sent it? Odds are that we’re listening in on some other schmucks who are barely past the point of figuring out how to start a fire without waiting for a lightning storm, and they won’t be sending any ships to deliver the secrets of unlimited, free, clean energy or the secret of anti-gravity to us any time soon.
Does that mean we should give up on SETI and related programs entirely? Not at all. They’re almost entirely privately funded these days
anyway and you never know what sort of fascinating signal they might pick up which could deliver some new scientific breakthrough. Or, if nothing else, we can watch the Alpha Centauri version of the Kardashians.