Encryption might be the reason why we haven't heard from aliens
theverge.com
theverge.com
Encryption is applied on the data layers not to hide that something is being transmitted, but what is being transmitted.
However scientists aren't even trying to detect signals with any sort of data in it, but merely radio emissions that look like they might come from something with an intellect.
If we haven't found anything like that yet, and encryption is supposed to be the reason, then that means that encryption would have to be applied at the most basic protocol layer in such a way that even the physical properties of the emission look like the universe's background radiation. Is there currently human technology that does anything similar to this?
Another interesting way to speculate is the "under our nose" concept, which is the concept that the existing distribution of stars and galaxies, as well as the recorded background noise, might be the byproduct of alien intervention. Binary star systems are a popular speculative example of "starivore" civilizations that consume entire stars that have been moved into the alien civilization's own star system, and perhaps some combination of multiple stars in a single system are not "naturally" occurring in the absence of alien influence. To an unsuspecting observer, some forms of distant astronomical-scale engineering could be mistakenly interpreted as natural astrophysics that the observers then incorporate into their standard models when refactoring to account for all of the observed data... Usually the simple explanations are correct, but when your models require really insane updates to handle the observed data, perhaps there are other explanations? At the same time though, what recourse would we have if 99% of the visible universe was already astro-engineered?
There is currently no evidence which suggests stars are being moved. We should see either large gravitational tugs or engines such as Shkadov thrusters. The latter should be plainly visible. The former should be easily detected by extrasolar planet detection methods. Unless the tugs are spherical, the light curves of the tugs would definitely pique interest. In any case, moving a star seems a rather extreme and expensive measure. It is probably more effective to consume the star onsite and use the energy locally or send only the energy back.
There seems to be no evidence of stars being consumed, either. Dyson spheres (or swarms) have actually been searched for locally by comparing visible and infrared wavelengths over sections of the sky. None have been found. Intergalactic searches have also been done by looking for galaxies which glow too brightly in the far infrared. No luck.
It is not just a question of a mistaken belief that the artificial is natural. The properties of light are the same here on Earth as they are billions of light years away. Further, for all those galaxies and stars to be engineered in the same way aross billions of light years (with some points being unable to communicate with others since the Big Bang), is all but impossible. Life would have to evolve at effectively the same rate and come up with the same solutions in all those hundreds of billions of galaxies (and yet somehow be different here in the Milky Way). Given the variety of life on Earth and the variety of solutions it has evolved, that seems unlikely.
Locally, if these events happend long ago, surely they would have been here by now, harvesting our star.
I personally just don't like definitive statements when there's no way for us to know the whole story.
http://news.discovery.com/space/alien-life-exoplanets/kepler...
http://astronomynow.com/2015/05/24/hubble-observes-one-of-a-...
Edit: to include the third link for Nasty1
Something similar should exist in the information theory. An encrypted signal can't be "too random", there should be some metric that distinguishes an intelligently designed signal from a random one. With spread spectrum and other tricks they can make it harder but not impossible to detect and separate from pure noise.
What is that metric? I have no idea, just trying to theorize. At least the opposite should be true, that for example the cosmic microwave background can not carry any useful/meaningful information other than just "signatures" of the particles that emitted the signal. So there should be some metric that's different for CMB and any signal that has something else in it.
Edit: I don't think the metric in question is entropy, although someone might convince us that it is. The problem with entropy is that, an object that consists of just a few types of atoms may emit a signal that would look very "orderly". That signal would be the spectrum with a few distinct frequencies in it typically emitted by those atoms.
It should if encryption is good. After all, security proofs for encryption define "secure" as "indistinguishable from random".
Why not?
Random data is not compressible.
Adding redundant data to random data will make it more compressible - less random.
The key word here is "computationally". A signal encrypted with a non-OTP symmetric key can be distinguished from noise without the key — unfortunately, for modern key sizes (128, 196, or 256 bits), the cost of doing so is prohibitively expensive for even arbitrarily advanced civilizations, unless (as Brice Schneier put it) they are building computers out of something other than matter that occupy something other than space.
Not sure what someone could possibly mean by that. Pretty much every celestial body has non-zero jerk. For instance, earth's acceleration is (to pretty good approximation) a constant times the $-e_r/r^2$, and the time derivative of that is definitely not zero.
Actually, if you think about it, the only plausible way you could have something in space with zero jerk and non-zero acceleration would be an interstellar ship maintaining constant acceleration, so the suggested rule is almost exactly wrong.
>a constant times the $-e_r/r^2$, and the time derivative of that is definitely not zero.
I don't see a term there that is time-dependent.
Any sort of steganography tries to achieve something similar. I wouldn't be surprised if something similar would be used in military radio communications.
The Drake equation of detecting intelligent life based on their signal emission needs a few extra terms for accounting for energy efficiency or perhaps even deliberate discretion (https://xkcd.com/1377/).
If we did pass through their data laser or whathaveyou, then perhaps it would be unintelligible encrypted information, but that's not something that seems likely to happen (even if things aligned perfectly, other star systems - particularly those with radio emitting civilizations - are probably too noisy to try to transmit through).
The only other alternative I can hazard speculation on is possibly gravity wave signaling? It's a bit of a stretch in my mind since the only real way to do that is to assume certain kinds of unproven particles like gravitinos (these are supposedly able to be interacted with in superconducting materials last time I read about them).
Steganography. Not "background", in the sense that images are generally considered useful, but it is hiding information in a place that a casual onlooker would not think to look.
> Encryption is applied on the data layers not to hide that something is being transmitted, but what is being transmitted.
That's exactly why this encryption would be strong. Initially, no one thinks to look for signals that don't look like signals.
But it doesn't even need to be encrypted communication. Highly compressed communication is also indistinguishable from random noise.
Of course, only under the assumption, that aliens are using the same technology as we are.
There is an EXTREMELY close analogy in EE / telecom land where people with no domain specific knowledge think all radio hardware, modulation methods, protocols, are all trivially interoperable with each other. Sure... go ahead and try to listen to trunked public service comms using a spark gap era coherer detector, good luck with that. Or try to listen to 60s era SSB voice using 30s era AM receiver. Higher order PSK/QAM is indistinguishable from white noise on a non-phase oriented receiver. This is all before we get into weirdness like trivial line coding, think of old T-1 circuits and B8ZS "scrambling" to get around the clock sync limitations of AMI line coding. Try to use an aircraft NDB receiver on GPS satellites or vice versa in order to navigate. Or connect an accurate clock built to sync to WWVB to the GPS constellation instead, or again vice versa. Telecom, being usually run at the limit of hardware when it was new, is even less interoperable than "computers in general". Given poor interoperation pragmatic results on our own planet, the odds of communicating with space aliens is basically zero, even the odds of detecting are almost zero.
Isn't this what Perl is for? To my eyes it fits the incantations part of the description as well.
Yes, although the details are important.
On a theoretical scale without any time limits and any space limits, anything every invented is interoperable with every other computer every invented. Hollywood is not really wrong there but just tosses out the practical issues because of the rule of cool. And "no time and space limits" is just wishful thinking as every computer has those constraints.
Of course, trying to hook up a Mac to a alien computer for transferring a computer virus is not impossible. It's just highly unlikely to succeed within a few hours of preparation. But it would have made a less entertaining movie. ;-)
Harder is something like "digital radio monodiale" which aside from having an unfortunate acronym is a digital shortwave voice modulation scheme... without having the specs in front it would be very hard to decide where to start. There are military intelligence people who do exactly this stuff with captured enemy signals, given an enormous head start of knowing the rough technology level of the other side and maybe some stolen documents. Still its not easy for them. A good analogy would be imagine a radio intelligence officer in WWII heard some 8VSB over the air broadcast TV from 2015... honestly I think you'd end up with question marks for at least 50 years trying to figure that signal out in 1940.
Right now, perhaps we are getting a 40 dB below the noise digital data signal from space aliens. Without any idea how to build the specific demod, we're going to get nowhere, and a level that low below the noise floor will not show up on any normal waterfall so we'd likely miss it.
Existing modes tend to reflect hardware ability. So some gear some of the time is stable enough to use WSPR modulation which is an ultra low bandwidth digital mode for HF (shortwave)... some gear drifts in frequency too much to use it, today. Oscillator stability can be improved to make it work, but replacing the IF stages with A/D converters won't do it, takes more than just doing demodulation in software with SDR instead of in hardware to fix the root frequency stability problem. Its possible space aliens modulation method would assume close in phase noise or IMD performance beyond 2015 capabilities, because for them its trivial star trek dilithium crystal stuff or whatever, but we're not going to invent the noise free monochromatic oscillator for another 150 years or whatever, so the front end performance of our radios wouldn't be good enough even with a preprogrammed SDR on the back end to demodulate. Another example, we don't have the technology today or the legal framework to do "real" beyond ultra wide band RF work, but there's no reason to think space aliens wouldn't.
We are detecting lots of potential planets with this method, so if technical alien civilizations were as abundant as planet we should have detected a few already. ;-)
BTW, we ourselves stopped to do the "blasting a signal in every direction" like we used to 50 years ago. With fiber optics, satellites, and other modern technology, we are leaking much less electromagnetic radiation. The chance of another civilization picking up us is shrinking.
What actually is the point of communicating at sub-luminal speed between star systems or galaxies, other than CETI projects? The delay between transmissions would make such communication impractical for day-to-day purposes.
Perhaps this is one possible explanation for the apparent lack of such signals. Either the aliens don't bother much with communicating at galactic scales, or they have developed a system of doing so at super-luminal speeds that eludes our current understanding of physics.
If this is correct then you would expect most artificial radio signals to be easy to detect and decipher, because the only plausible use for such signals is long-term communication with alien civilisations. And you might also not expect to find many of them.
Turbo Codes and LDPCs used to transmit data over noisy channels (like NASA uses in deep space satellite communications or UMTS and LTE networks) look just like noise. I don't think Seti or astronomers have ever tried to analyze noise for some alien codec that might be transmitting.
They can't. "It looks like noise" isn't a metaphor, it's a mathematical truth... it is indistinguishable from noise.
This is, IMHO, another one of those cases where people like to do a bit of social signaling with their fashionable misanthropism, but we actually know quite a bit about this problem. The optimal solution for using the electromagnetic spectrum for signaling, even with our current level of technology, is to use it in such a way that it looks like noise due to compression and due to not using any more power than necessary, in any direction other than the necessary one. Of course aliens do not sit there using four or five (if not six) orders of magnitude more power than necessary by broadcasting in all directions instead of using a directional beam, and of course they do not sit there and transmit in an uncompressed format that is an obvious signal, so of course we don't see their transmissions. It would be bizarre if it were otherwise. We have no reason to believe that aliens, who live in the same universe as us and are subject to the same engineering constraints as us, would be particularly prone to missing this incredibly obvious optimization.
(Math may be the one true cross-universe universal, but within this universe engineering is pretty universal too.)
So I can't see how your comment has any basis in fact.
You're only going to compress a data channel if you're in a hurry. When a message is going to take decades or centuries to get somewhere, you're more likely to keep the encoding as simple as possible to increase the chances of reception.
Besides that, I can't imagine radio being used for interstellar communication at all. It's fine for "Is anyone there?" but unless your aliens live at geological rather than biological rates, it's far too slow for almost anything else.
"Besides that, I can't imagine radio being used for interstellar communication at all. It's fine for "Is anyone there?" but unless your aliens live at geological rather than biological rates, it's far too slow for almost anything else."
Well, it's the fastest thing available unless you're basically willing to hypothesize magic. Anyone willing to do so is welcome to do so, and I'm serious about that; I just advocate that you be aware that you've switched to advocating magic. There's a difference between reasonable speculations based on real physics and arbitrarily advanced engineering, vs. new physics that despite all our research we still have little more than a whiff of, if that, and keeps crawling into ever more exotic energy domains to even peek at.
The point is that compressed transmission actually is simpler, and a formalized error correction scheme is much more reliable than relying on redundancies that arise by chance.
What about the parent comment belies anything factual? There is no data on alien transmissions, and the efficiency of compression and formalized redundancies just is, as a result of the math, not as a finding of collected data, even if real world data confirms what is mathematically understood.
That's a bold statement.
Encryption makes the bits look like noise, but you still have to turn bits into signals, and that has structure.
Efficient signaling methods look a lot like noise, but any safety margin makes it distinguishable from noise.
Beyond that, increases in noise in specific bands are still a notable event.
Even if it's spread across many or all bands, what is causing that.
Only highly directional signals would be hidden from us.
And of course transmissions might be too weak to see, but that is not what we're talking about here with the type of signal.
Or perhaps this was just some light-hearted conversation which has been reported as "news" because Snowden was involved. I can as well say that we have not yet heard from the aliens because we are yet to discover the Mass Relays and the Citadel (apologies to those who have not played the Mass Effect series of video games and this statement makes no sense).
It's more likely that we and the aliens wouldn't be using the same technology.
Any intelligent aliens are very likely to be using the electromagnetic spectrum for wireless communications. They might use it in somewhat different ways, but the technology is still essentially the same.
Now, for interplanetary signals, radio does not look that interesting.
There's the problem that it, like everything else, is jut too damn slow. So just the assumption that long distance communication is common is already iffy.
Then, radio is either too hard to manage, or has a too long wavelength. Yes, some hyper intelligence out there may think differently, but from our current understanding, it looks way more likely that such hyper intelligence will still find it easier to send matter, neutrinos, or whatever it is that composes most of the Universe.
Many of our radio signals are detectable from terrestrial sources such as radio and air TV stations. Even Ham radio signals throw out enough power for their signals to be easily detected beyond our solar system.
For interplanetary communication, tight beams would make way more sense than broadcast. And unless one of those beams is directed at us, we aren't likely to intercept it. This is really what SETI is looking for because it's the easiest thing to look for.
Getting a chunk of signal with modulation or one containing repeated patterns would be a world changer.
Your parenthetical is a good question.
We ourselves have sent a message to M13, a globular cluster ~20K lya. (See https://en.wikipedia.org/wiki/Arecibo_message) The only reason? To say "We are here." The thinking behind the choice of target was that the stars are close together so for one message we get more likely reception. That thinking was flawed because stars in a globular cluster are hot, young, and short-lived, so unlikely to support life, much less complex life.
We will probably begin sending similar messages when we discover more likely candidates. We are very close to being able to detect the atmospheres of Earth and super-Earth exoplanets. If we find one that contains a significant amount of free oxygen, it will be a good candidate for life, and I can certainly see us sending a signal to these planets.
The point of such a message is that for relatively small cost, we can potentially discover we are not the only intelligent life in the universe.
Additionally, the sheer knowledge that could be acquired if both species beamed constant signals to each other about their cultures, scientific discoveries, and etc., would be damn near priceless. Even if we found a civilization slightly behind ours or on the same level as ours, there would suddenly be two Earths with both similar and dissimilar problems with both similar and dissimilar solutions to those problems. Our knowledge of the universe and our ability to solve problems would grow, even if our mutual civilizations lagged behind each other by (say) 100 years due to the distance.
Lacking that, I can't imagine sending matter would be very cost effective relative to radio.
I don't see any reasons to believe they'll be using the RF spectrum. Simply because RF is about all we can manage to pick up is not sufficient reason.
1. https://en.m.wikipedia.org/wiki/His_Master%27s_Voice_(novel)
https://en.wikipedia.org/wiki/Fermi_paradox
Related statistics: Doomsday argument German Tank Problem Capture Recapture
Though, strangely enough, only when you count it from the performative side. That is I bet overall more words are spoken each day than written down (or otherwise technically transmitted). On the receiving end, ie. hearing/reading, due to the "broadcast" nature of newspaper, radio, TV and the internet, maybe more communication is technologically facilitated than not. That is more words are read or listened to than heard directly from another person. I wonder if and when that happened.
That and our limited brain capacity, which prevents us from recognizing and/or understanding a message from an advanced alien civilization.
If all communication itself on Earth were encrypted, how much of a visible signal would we still emit? You wouldn't be able to decypher the communication, but you'd still see that something is happening that's requires a structuring intelligence behind it. Unless they pay special attention to not only encrypting their communication but masking it as a natural phenomenon, steganographically.
If I shout an encoded message to you in a restaurant, the other people won't know that I told you to order the creme brulee, but they will know that I told you something. I'd have to discreetly tap my plate in order to mask it.
And even aside from that, you'd need to mask all other emissions, even those not designed to facilitate communication. On earth, you don't have to intercept and decrypt a rocket launch command, you can tell by the infrared (or whatever) emissions on your spy satellite.
To my eternal regret, I didn't call him on the fact that those two blocks are not arbitrarily composable.
Both encryption and compression make the resulting data look random (and you can't compress encrypted data), and compression seems to be a much more likely candidate.
P.S. And spread-spectrum transmissions, as someone else mentioned.
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