For those who think life is rare

[Nereid]

Sometimes semantics create the illusion of disagreement where none of any substance exists.

Thank you Chronos!

Doing a little cut&pasting, to get all the key things in one place ...

Unfortunately, the logic we would use to determine whether or not intelligence is common would have to depend on a model of universe creation, which of course doesn't exist. There are many possibilities:
1) Intelligent Design (the kind consistent with science) - No kind of statistical inference could be made about intelligent life. We have to just look and see.
2) One Universe with random laws - Intelligence likely exists elsewhere, by the Copernican principle.
3) Many universes with random laws - We would only see ourselves in a universe in which we could exist. To infer the likelihood of extraterrestrial intelligence, we would have to integrate under the space of possible physics times the density of intelligent civilizations within them to determine the likelihood of us being in a "multi-intelligence" universe. I won't try to guess at what the result would be.
4) Many universes evolving towards intelligence (perhaps it sustains their existence) - Intelligence likely exists elsewhere, since the universe would likely be specifically tailored to giving rise to intelligence.
5) Many universes evolving towards black hole creation - Not sure. Universes that create many black holes would likely also be long-lived universes, but it's not obvious that it would favor the formation of life in any other way.

And the logic would have to incorporate a great deal more than models of creation!

Such as? I think reasonable knowledge of the generative model (in this case, the particulars of universe formation) would be enough to do inference. The basic assumption going into the above is that, of all intelligent civilizations in all universes, we have an equal probability of asking this question from the point of view of anyone of them.

How about models for/of:
- 'intelligence'?
- estimating the 'characteristic time' of 'intelligence'?
- estimating the 'lead time' for 'intelligence' (assuming the universe model(s) are not 'steady state')?
- estimating the 'lifetime' of 'intelligence' (not - necessarily - the same as 'characteristic time'; model-dependent?)?

re 'intelligence', we would need to have a handle on the extent to which it is 'binary' ('intelligence' is either present or not) or not; if 'continuous', or 'can occur in a range of discrete states', then a handle on how all the above would vary, by 'state of intelligence' (or whatever), ...

The idea was that these models of intelligence would have to be derived from the parameters (i.e. physical laws) of the universe in question, as I specified in item #3. There would not need to be more information, just more work. In some cases, however, I think inference can be done without detailed models (that is, we can use our intuition). In point 1, for example, the answer is very easy -- there's no way for us to infer the probability of extraterrestrial intelligence because the model invokes something not governed by chance. In #2, I think we can just invoke Occam's Razor, since no anthropic selection biases are present. In #3, we would have to derive the things you're describing in detail. #4 is even more biased towards multiple intelligence than #2, so the inference is obvious. Finally, #5 would probably have to be worked out in detail as well.

I'm not suggesting we can get definitive answers, just that we can develop an intuition for what would be probable if we had a generative model with which to work. The issue of priors can be debated -- Do we choose a random species? A random point in time of intelligent life? A random organism? It's not clear. I would still contend, however, that none of the conclusions I've drawn so far are dependent upon that choice.

ST and I may be 'talking past each other' ... try substituting 'asteroids' for 'intelligence' in the above - does it make any difference? How about 'a&W3'? or 'John Bahcall'?

Also, there seems to have been a slight shift at one point "intelligence" -> "intelligent civilizations" -> "intelligence"

 

[SpaceTiger]

Doing a little cut&pasting, to get all the key things in one place ...ST and I may be 'talking past each other' ... try substituting 'asteroids' for 'intelligence' in the above - does it make any difference? How about 'a&W3'? or 'John Bahcall'?

Perhaps I'm misunderstanding you again, but I don't think you could have exactly the same discussion on asteroids because there's no issue of anthropic selection bias. I don't know what a&W3 is and I'm not sure any of this would make sense when talking about an individual person, assuming they actually were individual.

If you're suggesting that we don't actually disagree, I think you're probably right, I was just trying to clarify my previous posts. The things you suggested above probably will matter, but I was assuming they were derivable from the universe generation model. Are we on the same page now?

Also, there seems to have been a slight shift at one point "intelligence" -> "intelligent civilizations" -> "intelligence"

I was being sloppy and using them interchangably because it didn't matter for the conclusions I was drawing. I think to really nail down the anthropic selection bias, you have to ask, "What are the conditions required for a being to ask this question?" Would this include a requirement for civilization? Perhaps, perhaps not.

 

[turbo]

I was being sloppy and using them interchangably because it didn't matter for the conclusions I was drawing. I think to really nail down the anthropic selection bias, you have to ask, "What are the conditions required for a being to ask this question?" Would this include a requirement for civilization? Perhaps, perhaps not.

Hi, ST! In the case of humans, what we commonly call "civilizations" nowadays arose from the trend toward agrarian societies, which allowed humans more control over their destinies. They could store seed, plant crops, force the land to provide more and more food per acre, etc and break away from the hunter-gatherer paradigm. This also allowed humans to accumulate material things, since their possessions did not have to be hauled all over the place whilst tracking down herds of animals to hunt, finding ripe fruit to eat, gathering wild grains, etc. They raised animals and plants for food right where they lived. It is no wonder that powerful, long-lived civilizations grew where water, nutrients, etc were plentiful (along the Nile, the Tigris, the Euphrates, the shores of the Mediterranean, etc).

I'm being long-winded, but the term "civilizations" could also extend to small tribal bands that hunted, gathered, and lived communally. The difference is that these folks left fewer clear traces, and we know less about them. Once the Babylonians and the Egyptians started writing things in clay and stone (even mundane stuff, like how many measures of wheat a farmer had brought to the storage building and how much he was entitled to retrieve) they made it possible for us to learn a lot about them. The early native americans, in contrast, who cooperatively hunted bison (and even mammoths, earlier) did not leave much in the way of records, but their civilizations were probably very rich and complex, and I wish we could know them better.

We can make an extension to whales and the great apes that travel in bands, form strong bonds, and observe social heirarchies. At what level of species intelligence and at what level of social complexity do we declare that these creatures have established a "civilization"? We'll have better luck nailing Jello to a wall than answering that one, I fear.

 

[SpaceTiger]

At what level of species intelligence and at what level of social complexity do we declare that these creatures have established a "civilization"? We'll have better luck nailing Jello to a wall than answering that one, I fear.

"Civilization" is a vague term. Fortunately, for the issue at hand, that question isn't relevant -- I only said "intelligent civilization" in one post as a substitute for "intelligence". As I already said, what we have to determine is the point at which the ETs could ask what we are asking (i.e. is there anyone else out there?). Not to say that this is an easy question either, but it certainly sidesteps the ambiguities you're referring to. Clearly, there is no other creature on Earth capable of having the discussion we're having. Keep in mind that I'm trying to establish a circumstance in which we could use reason to develop an intuition for this question, not try to answer it myself.

Such an intuition might be impossible to develop, but there are things that may simplify the logic. On earth, intelligence seems to be a runaway process. That is, the complexity of our brains seems to be far beyond that of any other earthly animal. This implies that the continuum of intelligence may, in fact, be multimodal. In other words, it may be that there are very few creatures with intelligence between us and, say, dolphins, but plenty on either end. If this is the case, then the question becomes binary; that is, is the creature intelligent or not? The ambiguities of a continuum could be ignored. Furthermore, civilization seems to have developed very quickly, indicating that any intelligent creature would become sophisticated enough to question the universe on a very short timescale, leaving the "lifetime" issue negligible as well. If both of these things are a general rule, then establishing our priors simply becomes a matter of "counting" intelligent creatures.

 

[turbo]

I only said "intelligent civilization" in one post as a substitute for "intelligence". As I already said, what we have to determine is the point at which the ETs could ask what we are asking (i.e. is there anyone else out there?). Not to say that this is an easy question either, but it certainly sidesteps the ambiguities you're referring to. Clearly, there is no other creature on Earth capable of having the discussion we're having.

I think your inclusion of the term "civilization" is key, though. An individual organism may be very intelligent, but without the prior support and and the passing on of knowledge throughout generations, it may be impossible for any reasonably intelligent being to even pose the question.

It seems inconceivable that you or I (without access to the scientific, mathematical, and philosophical knowledge of the centuries prior to us) could look at the night sky and say "those are stars and they are each just like our sun, but that big glow over there (M31) is another group of stars like this one, and there is a great possibility that there are other planets around lots of those other stars". We stand on the shoulders not only of giants, but of countless generations of deeply committed seekers of truth. Sometimes they were right, sometimes wrong, but the key fact is that our "civilization" made it possible for us to save, transmit, and re-interpret their insights. This could not have happened without the continuity and stability provided by our "civilization". The collective wisdom of a society is essential to the abilities of its members.

 

[SpaceTiger]

I think your inclusion of the term "civilization" is key, though. An individual organism may be very intelligent, but without the prior support and and the passing on of knowledge throughout generations, it may be impossible for any reasonably intelligent being to even pose the question.

Yes, I am on the same page with you there, but I'm saying that what doesn't matter is our definition of the term "civilization", because it's just a means to an end, which is answering the question I'm posing. Many of the complications you brought up in your other post (concerning history and biology) are mostly ambiguities that arise when you're trying to come to a common consensus on what you're going to call a civilization. I agree that they're important for that purpose.

However, we know without a doubt that, for our purposes, the result was very simple. Humans evolved to ask the question (with the help of a civilization), but no other earthly creature did. What I'm getting at in the second paragraph of my last post is twofold:

1) This result may have been inevitable (that is, all intelligent creatures may develop to ask this question in a very short time).
2) Intelligence may be very easily defined (if the distribution is really multimodal) and we could immediately rule out creatures like whales and great apes without getting into the details of our definition of "civilization".

I admit that I don't have enough data to say these things with certainty, but there are good reasons (some of which I gave in my last post) for thinking they're true.

 

[turbo]

http://news.yahoo.com/s/ap/20050902/ap_on_sc/clever_whale

I thought that this might be an interesting addition.

 

[Nereid]

http://news.yahoo.com/s/ap/20050902/ap_on_sc/clever_whale

I thought that this might be an interesting addition.

If I'm not mistaken, this kind of behaviour - broadly - has been observed in several species of mammal (chimps, dolphins, gorillas?), and also of avian (rooks?).

That several other species have the capability to build 'mental models' of the world has now been demonstrated quite solidly, ditto that they can engage in 'conscious' deception, 'conscious' (i.e. out of 'choice', not 'necessity') cooperation, etc.

The main thing 'lacking' - from our {insert favourite adjective here} perspective - is a means of communication as rich as our spoken language (the written part is a mere detail).

As to whether an 'intelligent civilization' (I agree with ST that, for our purposes here, re Homo sap., the details matter little) has some inevitability (i.e. the 'rules of the universe' lead inexorably to the instantiation of an intelligent civilization, some individuals within such then turn around and ask the question in reverse)?

BTW, SpaceTiger clarified my 'asteroids', 'John Bahcall' etc exercise ... it's not a free parameter, whatever you insert into the slot in the sentence (logic proposition?), it has a bounded meaning, something akin to 'is able to ask the anthropic question about the universe'.

Of course, I would argue that isn't science, if only because (so far) there is but one data point.