Science Interviews

Interview

Thu, 25th Sep 2014

Is there anybody out there?

Duncan Forgan, University of St Andrews

Listen Now    Download as mp3 from the show Alien Hunters: The Search for ET

We can probably detect places in the galaxy that might harbour life, and we might be able to Parkes radio telescope viewed from the visitor's area.tell whether itís intelligent or not, but what are the odds that theyíre there at all?

50 years ago astrobiologist Frank Drake proposed an equation that now bears his name to estimate of the likelihood of discovering intelligent extraterrestrial life in the galaxy. Astrophysicist Duncan Forgan has been using computer modelling together with recent astronomical discoveries, to build upon Frank Drakeís work to get a more accurate idea of whether thereís anybody out there, as he explained to Graihagh Jackson...

Duncan - Well, the Drake equation is a series of seven or eight terms, depending on who you speak to. These terms get multiplied together and when those terms are multiplied together, you get a number, and that number tells you, if you look up at the night sky, thatís how many communicating intelligent species there are.

Graihagh - Okay, so in this Drake equation, you start with how many stars are forming every year in our galaxy and then you subtract out all the stars that donít have any planets around them, right? Because you canít have life there, and then you subtract out all the planets that are too far or too close to the sun to support life, and so on and so on. You get the idea. Until finally, you come up with the number of planets, with intelligent life, that could transmit radio signals and be alive right now. So when you slot all the numbers into this equation, whatíd you get?

Duncan - Typically, when I try and write down numbers in this equation I get the total number of intelligent civilizations to come out in quite small numbers, letís say ten civilizations in the milky at this point in time.

Graihagh - Ten. Does that include us or exclude us?

Duncan - Strictly speaking, that includes us, so you should take one off. It should be nine.

Graihagh - Nine? Thatís even worse!

Duncan - Yes. Itís quite a tough challenge. Before we get into this, I should just point out that SETI scientists and astrobiologists donít use Drakeís equation as a predictive tool. Itís quite clear that itís very simple and kind of cuts out a lot of the nuance and the sophistication required to make an answer to that kind of question.

Graihagh - Iím wondering 50 years on, is there not a better way to make a more informed guess?

Duncan - Other ways you can look at this question would be to say, okay, we have statistical information on how stars form, we can say things in a similar vein about the masses of planets, we can say things about the likelihood of them existing a certain distance from the star, so you can build up a statistical picture of what the Milky Way looks like in terms of its star and planet population. And once you have that, then you can essentially build a model in which you can test different scenarios.

Graihagh - So what predictions have you been able to make?

Duncan - So when I first started doing this, I ran several different scenarios. Some were quite optimistic and some were quite pessimistic. And over the course of the Milky Wayís existence, I showed that there would be somewhere between, you know, 300 and 30,000.

Graihagh - Not so many given how many stars and planets there are out there then.

Duncan - Thatís right. Of course, these are very speculative numbers though, because weíre still stuck with the same problem that we just donít know how life forms on other worlds and we donít know really how that life becomes intelligent. So youíre still saddled with these uncertainties but you can say given our uncertainties and making some sensible educated guesses, here are some nice sensible looking bounds in which we can put those numbers. 

Even when you take a fairly optimistic view of the equation and you put in some quite generous values for some of the terms and if you get a number thatís say tens of thousands, which sounds like a much bigger number. The Milky Way is very big, itís very big in space, itís about a hundred thousand light-years across and it is also very big in time, itís billions of years old. So we have this kind of dual quandary of how you get two civilizations to be close to each other in space and close to each other in time to appear about the same time. If one sends a radio signal, the other can see it before the other civilization goes defunct for whatever reason that might be.

Graihagh - And by Duncanís calculations, intelligent life that can transmit radio signals across the galaxy are likely to be alive for just one thousand years. A thousand years in a galaxy that is 13.2 billion years old with 300 billion stars and many, many more planets. When you take all of this into account, it seems pretty improbable that if there is anyone up there that will ever get the chance to talk.

Duncan - The probability might be low but that doesnít mean itís impossible, it just means that itís improbable. So even if we carry out a search knowing that weíre likely to fail, actually failing in the search is quite important because again, Iím just a theorist with a computer making some assumptions. At the end of the day, if you want to do it scientifically, you have to go out there and test it. So, youíve to make sure that youíve got observations to back up your theories and if we made a null detection after a significant and deep search, that has a lot of information in it as well as the opposite case where did detect something. It will still tell us something quite fundamental and important about what it means to be human.

Graihagh - I was gonnaí say what would that mean if we were the only sentient beings out there.

Duncan - It means that our existence is quite lonely and quite unique, and that human life in itself is even more precious than we might have thought originally.

Graihagh - And in some senses I guess then that would also mean that intelligent life of the whole galaxy rests on our shoulders.

Duncan - Well, in that sense, the stewardship of the Earth is not the only thing we are stewards of. We become stewards of a much larger volume of the universe and we have to be very careful and look after it if that is the case. So again, that has very strong implications for how we should behave as a civilization.

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Very large.


No. It's impossible to translate a message unless you know certain things about whom you're communicating with before hand. Since you don't then it's impossible. For example; you have to know if they reason/think/deduce in the same way as we do. You have to have some commonalities in which you can establish what certain words or ideas are. For example; how would you translate the word "pretty" to a species which has no concept of aesthetics?

Note: Please note that I've changed my responses. I made the mistake of thinking that the question was about us detecting/finding life out there rather than it existing. Those are two very different questions and I mistook one for the other. My apologies. PmbPhy, Tue, 30th Sep 2014

I think that intelligent life must exist but the distance would be so great that no interchange of communication would be possible considering the speed of light and the size of the universe syhprum, Tue, 30th Sep 2014



When you consider the things we donít know about the visible Universe (and thatís just the things we know that we donít know), and add that to the ďnothingĒ that we know about what might be beyond that; the only answer to that question must be a resounding ďdonít knowĒ.



Whilst I agree with most of Peteís post, we canít be sure that there are not intelligent beings out there who have been studying us for long enough to know our language.  I doubt it, but thatís just an opinion.
Bill S, Tue, 30th Sep 2014


If they can observe us then that's an entirely different ball game. After all, that's how infants learn to speak. :) PmbPhy, Tue, 30th Sep 2014



The OP was ďintelligentĒ.  You said you thought there was not even a remote chance of being successful.  Now you include non-intelligent which shifts the goalposts somewhat. Letís just return to science.  There must be plenty of other forums on which we could discuss social issues if we wanted to.
Bill S, Tue, 30th Sep 2014



The OP was ďintelligentĒ.  You said you thought there was not even a remote chance of being successful.  Now you include non-intelligent which shifts the goalposts somewhat. Letís just return to science.  There must be plenty of other forums on which we could discuss social issues if we wanted to.

Bill - I never said "intelligent or otherwise". What gave you the impression that I did? Where do you think I said it? I had to change my response in post #3 because I misunderstood the question but I didn't say it there either. PmbPhy, Tue, 30th Sep 2014

I can do no better than copy my response to a related question:

alancalverd, Tue, 30th Sep 2014

I have found intelligent life that is not human..

On Earth.

Try beating chimps in this task:

https://www.youtube.com/watch?v=zsXP8qeFF6A
UltimateTheory, Tue, 30th Sep 2014



And I have found very little that is. alancalverd, Wed, 1st Oct 2014

Communication with intelligent aliens could actually be easy, apart from dealing with long time delays if they don't come a lot closer. It would be easy enough for intelligent computers to show each other images and videos, naming things and actions that take place so that they can learn each other's language. In the old days when Captain Cook was exploring the world, they could stop off in places that had never been contacted before and hold competent conversations with the natives within as little as three days - they had experts with them who could learn the basics of languages fast just by working with a native and getting them to name everything around them and name actions and the like. Intelligent computers (which we will soon have and which any visiting alien would certainly have) would be able to cut this process down from three days to three seconds, and then there would be no communication barrier between us. David Cooper, Wed, 1st Oct 2014



Dear Bill,

I asked you where you got the idea that I said something like this but you never responded. Please let me know where you got such and idea. I'd really appreciate it. Okay? Thanks. :)

BTY - Who's the "OP" anyway? PmbPhy, Thu, 2nd Oct 2014


Hi David! :)  I still have to say that disagree. Please note that I'm not saying that I know this as a fact and its impossible for me to be wrong. I'm merely going by instinct right now and the results of the thought I've put into this over the last 25 years.


Are you aware that it's quite literally impossible to communicate which is a person's right hand or left hand using such signals?

Also as I implied in my previous post that'd be fine for giving names to such things as objects and perhaps even actions but when it comes to concepts like "My girlfriend is pretty." it might be impossible. Especially if you're communicating with a species which has no concept of aesthetics.

BTY - There's a page under Wikipedia about this. It's at http://en.wikipedia.org/wiki/Communication_with_extraterrestrial_intelligence


That's because they were both humans and thus both thought the same way. Both knew what water is. Captain Cook could tell a native which was his left hand by standing next to them and showing them by comparison.  There's something universal between a beautiful woman and a horribly ugly one. Although if the chief of the tribe said "I want you to marry my beautiful daughter." then I'd suggest talking a look before accepting. Lol!!


That's be impossible regardless of whether I was right or wrong since you need more than a few seconds in a conversation to talk about various concepts. E.g. if you walked into the alien's kitchen and he/she/it started to tell you about his family then it might take hours before he got around to talking about a new kind of physics that they've learned and we haven't and therefore we wouldn't know the new terms they've created to defined the new concepts they've discovered.

Suppose Captain Cook was a physicist from the 21st century and went to an island that no man has ever set foot on before. How would Captain Cook explain what Color charge conservation is? :) PmbPhy, Thu, 2nd Oct 2014

Language of physics is mathematics.
You might/should have no single word needed to describe it.
Discussion about mathematics should start from showing that we're using decimal system. Aliens might use different system.

People searching for aliens in cosmos are often saying that finding number pi signal (or primes) would reveal that it's signal from aliens. These people often have no idea how pi number looks like in binary system... UltimateTheory, Thu, 2nd Oct 2014


If you were talking about my response it my last post its not clear what your point is. While its true that math is the language of physics is math that can't be taken to mean that all words can be extracted from all physics texts and journals and leave the content unchanged. PmbPhy, Thu, 2nd Oct 2014

Yes, it can be, and should be, if it has to be universal for deep cosmos alien species.

The first stage of discussion should be establishing their unit system. What is their kilogram, what is their meter, what is their second.

Ratio between proton/electron mass-energy is universal 1836.15
also ratio between proton/deuterium, proton/helium-4, proton/neutron, muon/electron, pion etc.
No need a word, just numbers representing rations and symbols we understand behind them. UltimateTheory, Thu, 2nd Oct 2014

Hi Pete,


Are you aware that it's quite literally impossible to communicate which is a person's right hand or left hand using such signals?


Ah yes - which way round would they display the images if they don't actually come here to see how we display them? Well, it would be a real problem if our communication link was going through something equivalent to a wormhole but into a different universe, but if the aliens are in our universe we could show them pictures of large objects like galaxy clusters which they could use to determine which way round the images should be displayed. After that's been done, it would be possible to show bits of video in which things move to left or right and to use the words "left" and "right" along with those videos to associate them with the ideas they represent.



That's true, but you're now exploring a special area based on human emotions/feelings. We'll have the same difficulty explaining such things to artificial intelligence when it can hold rational conversations. It's possible that most evolved aliens will have similar kinds of feelings with good ones and bad ones to drive attraction and repulsion, but we may be exceptions and so that might not be the norm at all. If they don't understand what feelings are, it'll be a devil of a job explaining to them why they shouldn't just do whatever they like with us because they simply won't understand what morality means.


That's because they were both humans and thus both thought the same way. Both knew what water is. Captain Cook could tell a native which was his left hand by standing next to them and showing them by comparison.  There's something universal between a beautiful woman and a horribly ugly one. Although if the chief of the tribe said "I want you to marry my beautiful daughter." then I'd suggest talking a look before accepting. Lol!!

I don't think a visiting alien would want to marry anything it found here - just getting out of its space suit would probably expose it to lethal bacteria (perhaps that's a subject for another discussion). The beautiful and ugly women might be hard to distinguish between for the alien, but if one was clearly malformed it might still be possible to get the idea across.

I think any evolved intelligence which enables a species to become a universal problem solver like we are will have to think in the same general way, and when they program high-level artificial intelligence they will be further forced to conform with the kind of universal thinking that is required by machines where feelings don't override reason. This means that our AGI and their AGI will be able to exchange images, video and sound with each other and learn to understand each other's language in next to no time, and these machines would have a fair idea of how to work around the feeling side of things with the species that created them, so they would be able to function as good intermediaries.


That's be impossible regardless of whether I was right or wrong since you need more than a few seconds in a conversation to talk about various concepts.

It would be more than possible - this process would not involve us or the alien species so we would not slow it down at all. Everything would be done by two intelligent machines exchanging images, video and sound in order to swap dictionaries of words while mapping them to meanings. Three seconds might be a bit of an exaggeration if one imagines this being done by a PC, but a conversation between two supercomputers could perhaps do the entire job in under a thousandth of a second, if it was running the right software (which we haven't quite written yet, but we're getting close).



If he has to communicate with an uncontacted tribe which is still living a Stone Age lifestyle, it would still take three days for his experts to get to the point where they can hold useful negotiations with the natives, and then years of education to get anyone in that tribe to understand much about physics. The same would apply if we were to try to communicate with Stone Age aliens, but we'd have to go to them or send a probe to them to interact with them, and we aren't about to do that.

Any aliens we can contact in the next few thousand (or maybe million) years will need to communicate with us through such means as radio or light signals. The delays in communication will make actual conversations impractical, but it will still be possible for each side to send images, video and sound in order to explain what the words in their language mean (the words simply being numbers which they might map to grunts, signs, voltages or whatever else their species might use as a way of talking), and then long texts containing knowledge and literature could be sent (and understood on arrival, though with a fair amount of confusion wherever feelings come into things), and lots of pretty pictures could be sent too, along with maps and descriptions to tell them all the kinds of things we would want to know about us if we were in their position. They could do the same thing the other way, and at the end of the process both sides would know a great deal about what the other beings were like long ago when these ancient signals were sent out.

How long it would take to transmit the essentials of this information would depend on the bandwidth of the method used to transmit the signal. If it's low, it could take days, months or years, but if it's high it could again take mere seconds - the only limit is in how much bandwidth is thrown at the problem. Given the long time delay before the message arrives though, there would be little need to go to the trouble and expense of throwing a lot of bandwidth at it. David Cooper, Thu, 2nd Oct 2014



Sorry to be slow in responding, Pete.  I always copy/paste quotes to avoid this sort of thing.  Could it have come from your first post, before you edited it severely? 
Bill S, Thu, 2nd Oct 2014

I think that we need a second reference point to tell how rare life is in the universe.

What I mean by this is, Lets say we found life on mars.  Because we found life so close to earth then we can say that if life occurred twice in the same solar system then we can reasonably deduce that life is probably somewhat common and almost every stable solar system has a chance to harbor life.

But if we found the closest life to earth on say zeta reticuli 40 light years away then we can reasonably use it as a second point of reference and say that life could be very sparse and life might occur ones every 10 or 20 solar systems.

Unless we find a second refrence point then we cant say for shore how common life is.

AS for communication and civilizations in the stars, That is reasonably far fetched.  Who knows if other life has a brain at all or intelligence? what if most life is crystal or gas based life forms. you see without a reference we Just cant say anything with any shred of evidence or mathematical probability. ScientificSorcerer, Fri, 3rd Oct 2014



Sorry to be slow in responding, Pete.  I always copy/paste quotes to avoid this sort of thing.  Could it have come from your first post, before you edited it severely?

It doesn't sound like something I'd say. PmbPhy, Fri, 3rd Oct 2014


Why would showing them such pictures objects help? Are you suggesting that we send them pictures of objects that we see and they also see and we both therefore have the same object to refer to?



No. I'm trying to illustrate that you can't simply translate words and think you're able to communicate with an alien species. That requires having a great deal in common. I'm sure you know that there are words or phrases in other languages which have no translation to the English language, right?


I never suggested any such thing. I'm trying to explain that there are things which can't be translated. In this case it's even hard for humans to explain what makes something the way it is. I used physical appearance as an example but it should never have been taken to mean that it has anything to do with the actual problem of communicating with aliens. I was illustrating the problem that there may not be things that can be described to an alien species.


I don't know what you mean by "involved" here. Please clarify. I hope you don't mean that we're assuming that an alien species that we contact must be more intelligent than we are? I see no reason for that to be true. The only thing I see being necessary is that they have more knowledge about interstellar travel than we do. Who knows? Perhaps we'll have that knowledge in 300 years. But in 300 years we'll still be humans. There is unlikely to be any advancement in human evolution in that amount of time so we won't be more intelligent as a species. Are scientists will just be more knowledgeable.


I have no idea what that means.


That implies we have such computers and we don't. Even if we did then I don't believe that there exist knowledge that is required to, say, translate a language that we've never seen before. Today there are dead languages that will never be translated. PmbPhy, Fri, 3rd Oct 2014



That's actually the easy bit. If you transmit a series of n x m binary bits whe n and m are prime, there are only two ways of mapping them into a 2-D frame, and the wrong way will have considerably more spatial noise since it will chop up contiguous objects. Any being with the wit and technology to receive and display the signal will have discovered prime numbers, mapping, and frequency spectrum analysis. 

You can be really clever and transmit n x m x l bits, from which your alien could eventually make a 3D printer model once he has sorted out his maximum entropy reconstruction algorithm.    alancalverd, Fri, 3rd Oct 2014

IMHO that's the wrong question, and the right question is this:

What are the chances that intelligent life has already found us? JohnDuffield, Fri, 3rd Oct 2014



That's exactly what I'm suggesting. We could show them a diagram of the structure of the visible universe as it looks to us when we look in their direction, and they would be able to see that it's done from our perspective rather than from theirs, making it dead easy for them to tell what "left" and "right" mean to us.


No. I'm trying to illustrate that you can't simply translate words and think you're able to communicate with an alien species. That requires having a great deal in common. I'm sure you know that there are words or phrases in other languages which have no translation to the English language, right?

There are different ways of expressing things, but they can always be expressed in more fundamental ways which eliminate the confusion. When you make your language accessible to aliens, you will automatically begin by using the clearest, most logical ways of expressing things rather than starting with confusing idiomatic expressions. There is nothing in any human language that can't be translated into another language - it may require a lot of explanation to do so, but it is far from impossible, and the amount of difficulty a word generates (in terms of how economically it can be translated) is inversely proportional to its importance.



But the only difficulty there is with explaining beauty, and that's where we get into areas involving feelings. Even then, we can explain a lot about why we find some people beautiful and others ugly, so it isn't an area beyond all understanding. If the aliens have any kind of feelings at all, they can use that to guide their understanding. A distorted face makes us feel bad while a neat face makes us happy. Symmetry has an important role in this, but it is not the whole story. The golden ratio also has a role. Aliens would be able to understand that fine.


I don't know what you mean by "involved" here. Please clarify. I hope you don't mean that we're assuming that an alien species that we contact must be more intelligent than we are? I see no reason for that to be true.

"Evolved intelligence" - what I mean by this is intelligence that came about through evolution as opposed to designed machine intelligence like AGI. Simple evolved intelligence can be quite unintelligent, but it may be good enough to work in a simple creature. As it evolves greater intelligence and becomes a universal problem solver like us, it has to conform to the rules of reasoning which enable correct thinking, so it ends up thinking in the same way as any other evolved intelligence regardless of the route it took to get there. With AGI, we miss out all the evolution and go straight for a machine which applies the rules of reason, but we are practically there already with our own minds as the pathway to high intelligence forces all species to conform if they are to become universal problem solvers.


I have no idea what that means.

If you are programming proper artificial intelligence, you want it to produce correct answers for everything it thinks about, so you set it thinking using correct reasoning rather than programming it to think in a shoddy way like a human. Humans come close to thinking the right way, but they let their prejudices override reason as their feelings dominate, so they find it difficult to reason in a pure way. By creating AGI, we will drive everyone to conform to more systematic, reasoned thinking and will end up thinking the same way as any intelligent aliens who have also created AGI.



We don't yet, but it isn't far off - if you were to put money on us receiving a communication from aliens before we have this kind of AGI, I think you'd be waving that money goodbye. And they will certainly have it.



There are dead languages which are preserved in writings which we cannot understand yet and which may never be understood, but they are not actively trying to teach us those languages through those texts. If they put little drawings after every new word to give us clues as to what they might mean, we might find it really easy to understand them. When it comes to communications with aliens, we will be actively seeking to make ourselves understood to each other, so it's a totally different kettle of fish. David Cooper, Fri, 3rd Oct 2014



That's actually the easy bit. If you transmit a series of n x m binary bits whe n and m are prime, there are only two ways of mapping them into a 2-D frame, and the wrong way will have considerably more spatial noise since it will chop up contiguous objects. Any being with the wit and technology to receive and display the signal will have discovered prime numbers, mapping, and frequency spectrum analysis.

That's not the issue in question. The issue is how you determine left from right. You can easily get the picture to look correct (even if you don't use prime numbers for height and width), but it may be reversed. It might not matter if it is reversed though, and indeed it's quite possible that different people see the world the other way round from each other - none of us can tell if we see it the way round that it actually is. David Cooper, Fri, 3rd Oct 2014

Gross left and right aren't particularly important to most species, though the chirality of some molecules determines their biological function. Faced with a coronal plane image of a human or a spider, I could probably work out that it was vaguely bilaterally symmetric and had a preferred orientation with respect to gravity. Given three projections and a scale (the hydrogen 21 cm line is likely to be a universal standard of length and time) I could make a fullsize model of it. So it's entirely possible for any life form that can control an electromagnetic technology, to initiate meaningful conversations with another.      alancalverd, Fri, 3rd Oct 2014

I think that we need to find some aliens before we can learn how to effectively communicate with them.  Which would mean hopping in a space craft to start scouring far off solar systems for signs of life.

In order to do that effectively we would need to go light speed or beyond.  Thinking about how to make cheaper and faster space craft.  (warp drives and stuff like that would be completely necessary) ScientificSorcerer, Sat, 4th Oct 2014

Intelligence seems to be the realization of not knowing enough, then start asking questions. If the universe works by emergences, meaning 'jumps' that you don't really can back track to their constituents behavior before this 'emergence', then intelligence should be able to pop up everywhere I think. yor_on, Sun, 5th Oct 2014

We recognise intelligence in another animal by its ability to surprise us. It is the antonym of mechanism. So we should be looking for the mechanistically improbable- like the "WOW signal". The difficulty is recognising the difference between a surprising signal and random noise.  alancalverd, Sun, 5th Oct 2014

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