Edward Snowden: we may never spot space aliens thanks to encryption | US news | The Guardian
http://www.theguardian.com/us-news/2015 ... on-podcast

'What's wrong, is it encrypted?'

'No, the software needs some poncey plug-in...'

It depends, if they want to be found like us, they will be sending it in the clear. If they are highly intelligent and looking to invade, you probably won't hear them coming.

On the other hand they probably won't be speaking any language that we would recognise anyway.

This is what i was thinking about when reading the article. Two human beings, even if speaking different languages, do have some common reference points, so they have something to build basic communication on. Without those common reference points, it strikes me even primitive conversation or translation is impossible.

When you translate something, you are aware what while the characters, words or even the grammar structure may be different, fundamentally the language is describing something you would describe in your own language. With an alien language, that assumption doesn't hold. There's no 'rosetta stone' there to start from. He had no chance at all of translating hieroglyphs until that stone was found, and the situation with an alien culture is there;'s nobody available to make it in the first place.

Alien transmissions would effectively be very strongly encrypted, not intentionally with a cypher, simply down to their nature being.. alien.

Scientists often assume that mathematics in universal, but I think even that may be a stretch. The fundamentals of the universe obviously are, but we're assuming the mathematics we have come up with is the only way of describing them...

The only thing that would be truly universal would be the natural elements in the periodic table. Hydrogen is hydrogen wherever you are.
How you would create a basis of communication from that however is anyone's guess.

I think their language would have to be incredibly alien indeed if we were to be unable to recognise that it represented any form of pattern distinguishable from random space noise. Even if they don't use nouns and verbs, there would still be phrases and repetitions thereof.

But on the other hand, normal radio waves can be picked up and you can determine that it is speech. Same with analogue TV, but there again, we know what sort of signal to look out for.

Who is to say that their digital transmissions are going to be understood by us, encrypted or not. What if they don't use binary, for instance?

That's just detail. Their languages would have patterns. That's all that they need to something other than random.
Whether you will be able to have a conversation with a civilisation thousands of light years away by electromagnetic means is a very different question, and one which may take rather a long time to answer.

Any signal can be analysed and mathematically you can say 'this is not random' (indeed, that's effectively what SETI@Home was all about). And maybe then you can discern patterns and repeating sequences. But there is not way to then 'translate' that into a language without reference points. We may know that 'sequence X' in a signal might repeat at the same frequency as the letter 'e' in english but that doesn't mean there's congruence between the two.

The nearest example I can think of is certain translations - from asian pictographic languages (say Korean) to western alphabetic languages. There's no way you could get from one to the other purely through statistical analysis. You need a start point, you need a set of common concepts to 'triangulate' your translation or you're just looking at patterns which have no discernible meaning. Traditionally that start point is someone who knows something of both languages. With an alien species, we simply don't have that. And if you don't have that, you can't begin to formulate a way to translate.

Even in fiction they accept this. In Star Trek (NG I think), the crew met a species whose language was allegorical - all members of the species had a known common history and communicated concepts and emotions exclusively by referring to events in that history. The crew did not have access to that history and thus the drama of the episode was that this was the first species they'd met where their translation technology had failed them.

As Davros suggested there are certain 'universal' concepts in the universe - the components of a hydrogen atom, the speed of light etc. and in theory you could build a form of translation starting from those very fundamental concepts but it would be a very long road to get to the point where you could even say 'hello'.

Langauge has a massive amount of underpinning all of us who use it are never aware of, because we can take those underpinnings for granted.

Surely we should just speak really loudly, never fails.

Ok, so assume we can spot language. Assume we can decode it into fragments that can give us an intelligible string of words that appear to make sense. That may be as far as we can go. We can't even decide human writings from the past with a high degree of certainty. Various forms if cuneiform are unreadable, despite being recognised as written text, evidently words with a syntax and grammar. And that's from humans on this planet.

I am reminded of a Star Trek TNG episode where the universal translator worked, but the use of words were quite different. It transpired that the alien's language relied so much on their legends and history that it was virtually impenetrable.

Jon mentioned the ST episode above. For reference the episode is called Darmok.

The original observation that led to the thread is extremely speculative. Going beyond it to how to decode languages when they are spotted is placing the cart significantly ahead of the horse.

I'm not certain the examples of indecipherable writings such as Quipu and Rongorongo are very useful. Whatever the surviving written examples of these languages may be (receipts, prayers, name badges) they are unreadable precisely because they are mere context free snippets of a much broader language that wasn't written. Advanced space aliens are unlikely to make such minimal use of their communications technologies.

I am not familiar with the Star Trek episode, but I presume they eventually teased some meaning from it. The probability of this is contained in the premise. All language uses public concepts to convey meaning in propositional form. The problem described there is not to do with the language, but with the meaning of the propositions. In the Star Trek episode, the meaning of what is said in the language is very difficult to comprehend, but it would only be entirely impossible if the language was private and therefore not designed for transmitting information.

The thought occurs that you're probably going to be facing some form of compression of any messages too.

The thought occurs to me that said aliens need to be able to distinguish the signal from the cosmic background, in which case it must be detectable as a non-random signal.

If it were indistinguishable from the cosmic background, how would the aliens talk to each other?

Hmm.. Only if you know when and where the signal is going to come. This is all theoretical, in fact it's very nearly 'a tree falling in the woods' stuff. But, say you have a way of transmitting a signal in code that looks exactly like background, and a way of successfully decoding that. If you can then agree between the transmitter and receiver when the transmission is going to happen and where in the sky it's going to appear to come from to the receiver, the receiver and only the receiver would then be able to decode it.

So you can make a useful cryptogram that looks indecipherable from random noise, but you have to externalise the key from that cryptographic stream in some way and somehow otherwise flag the start of the cryptogram in the stream of random data.

Our real world equivalent would be 'a signal very similar to noise sent on radio frequency X and time Y' that somehow converts to a crypto stream that is decipherable with an agreed key.

As far as I can see, there's no way to send a decryptable signal that is on the surface indistinguishable from noise without externalising important aspects and agreeing them by some other channel or means. So there's no way to send an encrypted signal that looks just like noise to a civilisation you have no previous contact with. But then again, logically, why would you ever want to do that?


Jon