I think SETI, the Search for Extraterrestrial Intelligence, is a wasted effort. Just to be clear, it’s not the concept of Searching for Extraterrestrial Intelligence that’s a waste, it’s the way it’s being done. I know I’m going out on a limb here, but there is a certain logic.
As I see it, SETI is about two things. First, to find out if advanced, technological civilizations exist, and second, to possibly communicate with them.
Our ability to communicate continues to advance, as it has for the last million years or so. Although there is no proof, I think the first human language was probably non-verbal, we call it body-language today. Later, the first, humans developed a spoken language. That development meant more detailed information could be passed to the next generation. Painting symbols on the walls of caves allowed more complex information to be passed across the barrier of time. That evolved into written language on stone or papyrus. Smoke signals allowed messages to cross larger distances. When we advanced to the industrial age, the telegraph was invented. Now we could send complex messages across thousands of miles. Now, at the pinnacle of human technology, we can communicate via radio. Images were recently sent back from a NASA probe, as it passed Pluto, billions of miles away. The point is, that at each stage of human evolution, we imagined that we had achieved the ultimate form of communication. At each stage, the next stage was considered magical, beyond all comprehension. Until the next level was reached.
In its current form, SETI is based on the idea that the way to detect, and communicate with alien civilizations, hundreds or even thousands of years more advanced than our own, is through radio. Just like native Americans would have tried to detect the presence of more advanced tribes by posting sentries on mountain tops to watch for complex smoke signals. Not a successful strategy.
Futurist Michio Kaku has suggested that single, or limited frequency, radio transmissions are a poor means of communication across interstellar distances. They are subject to distortion by gas and dust clouds. A better way would be to use a larger number of frequencies, each carrying a tiny part of the message, which could be reassembled by the receiver. We use similar methods, such as RAID arrays, to spread data across multiple hard drives. If any single drive fails, 100% of the data can be recovered from the others. Even if aliens are using something as primitive as radio, it’s likely they are using some similar technology. If so, we probably would not recognize the part of the signal we intercept as containing data.
Another consideration is encryption. Even if you use your smart phone to call a family member in the next room, the data is encrypted. OK, not that well, since NSA or the FBI can probably listen in.
Encryption makes it unlikely we would ever recognize any messages sent by aliens, except those that might be broadcast with the specific intent to be deciphered by other civilizations. Let’s keep in mind that we can’t perfectly translate messages left by other humans from a few thousand years ago. Those human messages were not encrypted, they were intended to be easy to translate.
There is another reason aliens are unlikely to use radio. It’s slow. Limited to the speed of light, it takes years or centuries to exchange a useful volume of information. We have to consider that either we, or the alien on the other end of the phone, might be extinct by them time an exchange of data is complete. Or they have moved on to other, more advanced, form of communication.
Imagine this scenario. You are 60 years old, your phone rings, and child speaks, “I can count. One, two, three”, then the connection is broken. You discover that the message was sent 55 years ago and has been bouncing around the world’s phone system all that time, and just now connected. The child must be close to your age, if it survived. If you could track down the house it was originally sent from, would you call back? Suppose the location was 8000 miles away. Would you get on a jet plane and fly there to speak with that person? The call might not be what it seems. It could be a scam, made to look old, and from an innocent child. The person sending it could have very bad motives indeed. What if your research suggests the call came from Nigeria? What would the cost-benefit analysis look like?
I think the right way to look for alien technology is to research faster than light communication. There is already some evidence that some quantum effects may allow this. It is by no means certain that even if it works, it would work across interstellar distances. Evidence that such messages exist, even if we could never decode them, would still change our view of the universe.
Embedded in all this SETI discussion is the huge assumption that aliens would advocate announcing themselves to other civilizations within radio range. Including those species whose culture is based on the extermination any other species that might be intelligent, or might someday evolve intelligence. Obviously, announcing yourself is potentially very risky. However, there is one case where such an announcement makes sense. If they believe that they are the most advanced, it would be good to discover emerging, potentially dangerous species before they can do much damage. Measures could be taken, either to eliminate or pacify them.
In one way, we should hope that extraterrestrials are not like us. Humans expand to every inch of the planet that is borderline habitable. We exterminate every species that annoys us, except for a few we consider attractive or interesting. Those we keep in zoos or cages, or domesticate, often for their meat or skin. It may well be that an advanced alien civilization inviting us into their galactic federation is about as likely as you inviting a group of rodents you find in your back garden to nest inside your house.
If we want to be admitted to the club of advanced alien civilizations, our first priority should be to clean up our act. The way we imagine such advanced beings, able to control their physical world, having limitless resources, and living in peace and harmony, is not consistent with the way we run our planet. To such a civilization, we would look like vermin. It’s hard for me to imagine meeting such an advanced civilization being to our benefit, unless of course it turns out we’re really cute and cuddly in their eyes.