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To date, SETI (Search for ExtraTerrestrial Intelligence) has focused on ETs who ‘phone home’ using the radio part of the electromagnetic spectrum, and even a very small region within that.
But what if ET’s phone doesn’t use radio waves? Sure the xkcd comic, is funny, but maybe it points to a deep flaw in our attempts to contact, or hear from, an ETI?
When Giuseppe Cocconi and Philip Morrison suggested the possibility of interstellar communication via electromagnetic waves in a 1959 paper in Nature, only radio was feasible, as we then had the ability to detect only artificial radio signals, if produced by ETIs with 1959 human technology. Since then we’ve developed the ability to detect a laser signal, brighter than the Sun (if only for a nanosecond) if it came from a source several light-years away … but lasers weren’t invented then.
What might ET’s equivalent of ants’ pheromones be?
Back in 1959 if you’d said that the Earth would, within a mere half century, started to go ‘radio quiet’, not many people would have taken you seriously. Yet that’s exactly what’s happened! Free to air (FTA) broadcasting, especially for TV, is being replaced by TV delivered over coaxial cable, optical fibers, or even the phone company’s twisted copper pairs. And where it’s continuing, as in satellite TV broadcasting, its power has dropped (today’s digital formats are more efficient than the old analog ones). Military radars, the brightest source of artificial radio waves by far, no longer broadcast in a single channel, but hop, rapidly, from frequency to frequency, to avoid jamming.
“Our improving technology is causing the Earth to become less visible,” says astronomer Frank Drake, SETI’s paterfamilias. “If we are the model for the universe, that is bad news.”
In the past half century SETI researchers have expanded the scope of their searches. Not only are far more radio channels being examined, but artificial signals in the optical are being sought too. How to decide which of the billions or trillions of possible radio channels to search? For example, the Allen Telescope Array will, when built, monitor a billion channels between 0.5 and 11 GHz – but that’s a trivial fraction of the entire radio waveband. Some ideas, however, seem cute; for example, the SETI Institute’s Gerald Harp has proposed searching at 4.462336275 gigahertz, in what’s called the PiHI range, because it’s the hydrogen atom’s emission frequency times pi. More seriously, Harvard University’s Paul Horowitz says optical SETI programs should really look at infrared frequencies “Stars are darker in the infrared and lasers are brighter and the smog goes away,” Horowitz says. Infrared allows astronomers to see into the galactic center, where dust scatters visible light.
There’s something rather ironic about SETI today; on the one hand, we recognize that our initial hopes were far too high, being based on overly simplistic assumptions; on the other, the tremendous progress in finding exoplanets has given us greater and greater certainty that Earth-like planets not only exist, but are, very likely, common. “All of astronomy has come to embrace this idea that there must be life out there,” says Harp.
So how to address the fact that we simply do not know what sorts of technologies a civilization like ours may have, a century or a millennium from now? After all, as Drake says “We are very conservative at SETI, we assume in our searches the existence of only things we ourselves have and know how to make.” Other scientists, and SETI enthusiasts, have proposed hunting in different electromagnetic realms, like gamma rays. Spacecraft that rely on nuclear fusion or antimatter-matter annihilation as a power source might produce such rays. But standard SETI strategy does not embrace such “speculative” scenarios.
SETI researchers, some say, should also contemplate what technologies supersmart aliens might possess and seek out the corresponding signals. In a 2008 arXiv paper, “Galactic Neutrino Communication“, John Learned of the University of Hawaii at Manoa suggested that ET could be sending beams of neutrinos Earth’s way. Energy requirements for such a beam make that scenario seem implausible, but not necessarily impossible. Detectors currently under construction, such as IceCube at the South Pole, could spot unexpected stray neutrinos. If a few with the same energy came from the same direction, astronomers would know something screwy was up.
In another paper, “The Cepheid Galactic Internet“, Learned suggests that ET could send a signal using a neutrino beam to deliver energy to a Cepheid variable. A Cepheid “blows up and comes crashing back down,” he says. “And the energy builds up and it blows again, like a geyser.” ET could leverage a Cepheid’s inherent instability by delivering a boost of energy that messes with the star’s schedule. Looking through existing data could reveal whether such meddling has occurred. “All that is needed is people analyzing for other reasons to do their analyses in another way,” Learned says.
Drake and most others agree that SETI’s approach should be multidirectional – let a thousand alien hunters bloom. The only ideas that don’t do anybody any good, Horowitz says, are the ones for which there is no conceivable way to look. “I’d like to keep an open mind,” he says, “but not so much that my brain falls out.”
Physicist Paul Davies of Arizona State University in Tempe, however, suggests that researchers don’t need to know what to look for. Find the fishy thing first, and then argue about its origin, he says.
As Davies has argued, maybe discovering ET does indeed depend on a thought revolution. Fifty years of signal-less searching suggests that the problem could lie not with the aliens among the stars, but with ourselves.
Maybe the sentient ants should not give up, just yet.
Sources: Science News. Cocconi and Morrison’s 1959 Nature paper (copyright Nature)
I’ve said it before, and I’ll say it again. I believe that our discovery of ET will be by accident. As our advances in technology increase, so will our abilities to do more things in the area of space exploration. Devices we’ll design to carry out certain kinds of missions, will unexpectedly, be that, or, those things that actually clue us in to their existence.
This is likely to happen LONG before any direct approach at doing so…..and….it won’t be too far off into the future. That’s if, it isn’t already occurring now, and we just haven’t been paying attention. 🙂
An optical approach might be possible by sending large flat objects in orbit around the star. This would create some pattern of transits that could encode a signal, at least a signal that says “We’re here.”
LC
LBC,
Yeah but didn’t papa Hawking say not to do stuff like that?
Perhaps the best place to look for alien intelligence is in human DNA?
It is probable that an advanced space fairing civilization would wish to remain and travel ‘incognito’ for a period of time when contacting a lesser evolved species. Also probable is the idea that by ‘diddling’ with human DNA an advanced race might accelerate the overall growth rate of intellectual evolution in our species.
Remember, it wasn’t all that long ago that we began to master electricity, the sky or LEO… but the ‘hits’ just keep on coming! AND at an apparently accelerating pace! This leads me to believe that CONTACT is not that far off…
Short story subject: An alien race visits Earth several times over the age of hominids and each time introduces progressively more sophisticated DNA snippets. Part of this built-in ‘programming’ is a short life span. Elements are added to the DNA sequence to ensure that occurs. This action assures that positive results are spread throughout the species at the optimum rate. At first CONTACT with this advanced civilization, we are given a universal ‘antidote’ which cures cancer and eliminates most diseases…. and are rendered a deep apology from our now seen as ancestral hosts…
“Earth. Mostly harmless.”
-Hitchhiker’s guide to the galaxy-
Looking within.
We may find the key(s)
to the universe?
Isn’t it interesting that Arthur C. Clarke gave us the concept of geosynchronous satellites AND the seed for 2001 – aka ‘Childhood’s End’
He saw perhaps the same?
And this is how the process works… pass it on~
Maybe some ETIs out there are not so worried about this. So we might find some strange winking of the parent star due to ETIs who don’t have this concern. I might be that to some intelligent life the idea of invading anything is as outside their mental faculties as brewing beer is to octopi.
Frankly, I think these concerns are a bit silly.
LC
It’s food for thoiught but then alien communication could be so far out of our frame of reference that we would never detect it so why worry, best to just listen for what we know. As for advertising our presence, given the Darwinian laws by which life develops anyone (anything) capable of coming to us could be a real danger. We should keep quiet and watch carefully, no doubt they will have come to the same conclusion, so we are looking for aliens who are probably hiding….
It only makes sense to explore every part of the spectrum. I believe it would be wise to send some sensors into different parts of the solar system.
If another planet was attempting to send us a signal, they would likely use something which works very well in a narrow beam and would survive many light years. They also have to “guesstimate” where Earth will be when the signal finally reaches us. This is why I believe we should have different sensors around the solar system… in case the energy they sent us missed. You don’t use a broad radio wave beam when attempting to communicate in space.
What would really blow my mind, is if other life forms have learned to communicate using particles to carry a message. These partciles could have the capability of moving faster than the speed of light! The ultimate means of communication.
Aqua,
These visits and accelerations weren’t done with the use of a monolith like in 2001 by any chance was it?
I’m still not a massive fan of waiting around for something to contact us. It really feels like a futile shot in the dark. Like being a teenage boy and hoping some cute girl is going to stop by your parents house and throw a stone at your window, hoping their’s a cute boy on the otherside.
So far, it seems the most likely direct route to finding other life (that we can recognize) is by seeking out where we would most likely find it: Other Earths.
Uncle Fred,
I think that will naturally happen after results come in from Kepler.
Aqua: you’re just babbling. Are you ok? not enough coffee?
I’ve long suspected that our search was too narow.
There seems to be an assumption that aliens will look, behave, and sense in ways similar to us. I don’t think that will be the case. I really doubht there will be humanoids with pointy ears, forhead ridges or blue skin.
More than likely, they maybe as different to us as we are to jellyfish. Suppose on their world, intelligent life evolves in the oceans, and they never even bothers to check out the stars, simply because they can’t perceive them.
On the other hand, they may not have contacted us because they don’t like us. A sufficiently intelligent species may think of us as polluting, warlike cockroaches that should be avoided at all cost.
We’re like the annoying neighborhood brat that keeps buzzing the doorbell.
Uncle Fred…
Although I laughed at what you said, technically you are right. As large as the Universe is, any attempt to capture signals from other life forms is a HUGE shot in the dark.
However, I still think it is worth the trouble, if we begin to use all the resources we have to become active in finding other life, rather than just sitting back being passive.
We need to begin to use all the technology we have, and network the information from each to become more efficient in this research.
Yet I do have some confliction with this research. Like Stephen Hawking, I fear any advanced life which is capable of traveling to Earth will likely have the capapbility to destroy us and use the planet for themselves.
What do you believe Earthlings would do to another world (if they had the capapbility to take it over), if they found it was suitable for them, and our Sun was about to destroy Earth?
Wow, now thats what I am talking about dude.
Lou
http://www.anon-vpn.at.tc
Personally I’ve never really been convinced by the idea that any suitably advanced civilisation would come out to this partof the galaxy just to plunder our planet and haul us off into slavery. There are plenty of planets, asteroids and assorted debris between us and them to satisfy their needs. While I certainly believe that there are space-faring civilisations dotted throughout the galaxy and there are no doubt hostile, warring entities they are quite probably ‘inbound’ from our position and much nearer the crowded part of the milky way.
@Aodhhan
“What do you believe Earthlings would do to another world (if they had the capapbility to take it over), if they found it was suitable for them, and our Sun was about to destroy Earth?”
The same thing we’ve always done.
To expect advanced aliens to technologically build and have found a method to just say “hello, we’re here” is much like writing words on the walls of public places. Earth is a parasitic planet many scientists state, so expect any form of contact to be to their advantage, even if it comes in the form of neutrinos, that have been discovered to morph between an electron, muon, and tau many times before reaching us. The message will likely be a deception full of luring enticements that will destroy earth.