Jobar

This is something I thought of while reading david's 'fine-tuning' thread.

In the mid-twentieth century, the physicist Enrico Fermi was discussing the possibility of extraterrestrial life. After going through the possibilities, and as far as could be determined the probabilities, of life on other planets in the universe, it was agreed that there could be thousands to millions of other intelligent races in the Milky Way galaxy alone. Fermi asked, "Where are they?" This has come to be known as the Fermi Paradox, and is the subject of many millions of words. I make no attempt to cover all the deep and subtle thought which has been applied to it; anyone not familiar with it can get massive amounts of info from any search engine.

I want to point out that it has some applicability to the argument for design. If the properties of this universe are fine tuned to allow life, and more specifically intelligent life- where is it? I have seen arguments pointing out that the Earth itself is not by any means custom made for humans; only a small percentage of its surface is well suited for us to live on in comfort. But I do not recall seeing any discussion of this on the scale of the whole universe!

I freely admit that this could conceivably be made into an argument for those who think that the Earth is in some way special to God; after all, as far as our (very new and very limited) technology can tell us, we are the only intelligent life in the vast universe we see. Still, it seems to me a far more convincing argument against design- if we are the only planet with intelligent life, then the universe is *not* well designed for intelligent life. We are simply the winners of an incredibly vast lottery- of hundreds of billions of galaxies, with hundreds of billions of stars per galaxy, we hit the jackpot!

beausoleil

If you do a search on 'anthropic principle' you will find lots of stuff about the fine tuning of the universe. You don't have to tweak physical constants very much to produce a universe with no planets whatsoever, for instance, or no elements more massive than helium.

Evidence of design, evidence of multiple universes or the many-worlds interpretation, or just a pure fluke. Who knows?

davidm

I was thinking of the Fermi Paradox too, though in a different way: If there are all these multiple universes floating about, "Where are they?" Although this would presume we would have some way to detect them, I guess.

This entire discussion may be in the wrong forum. The fine-tuning argument has been predefined as an argument for a supernatural fine-tuner. More, it seems to have been predefined as an argument that the supernatural fine-tuner had fine-tuned the universe for some purposeful outcome. With respect to the latter, even if true, there is no way to determine that humans were the goal of fine-tuning. The goal might as well have been stars or grains of sand or beetles, all of which exist in vastly more numbers than we do.

What if we were to decouple fine-tuning from a supposed fine-tuner? Would there then be anything left to puzzle over? I also agree that if the universe were fine-tuned for life, we ought to see a lot more of it under a lot of different conditions. We don't. Yet for that very reason we also ought to be highly skeptical about the idea that universes with wildly different parameters from our own would somehow evolve wildly different forms of life. Life does not seem to be at all elastic, so far as we can tell, except right here on earth.

Jobar

davidm, do you want your original topic on fine tuning moved to our Philosophy forum, or perhaps Science & Skepticism? I certainly have no objection to leaving it here- but being that this forum concentrates on arguments for/against EoG, if you want to put a different 'spin' on the discussion we can accomodate you.

Whatever your choice, I again thank you for introducing this fascinating discussion to Internet Infidels. As you can see, it is spawning new threads- always a sign of a deeply interesting topic!

echidna

Does not the Fermi Paradox assume a relatively high probability of intelligent life creation ? I remember 30 years ago scientists were quite confident of re-creating life in a test-tube, primordial soup + lightning + lots of time => cappuccino machines + mobile phones

A few decades later & it seems a little trickier (putting it mildly !!!). It seems to me that amongst the endless (im)probability arguments in E/C, both sides contain some truth, firstly in that what we see around us today is incredibly improbable & secondly that “incredibly improbable” does not mean impossible – though I know this rests quite comfortably with most evolutionists.

Hence, maybe there is other intelligent life, but just not common as Fermi had anticipated.

But it still doesn’t seem to wash out the FT Argument. FT rests simply on our existence, alone or not, one could say that with the benefit of intelligence, the rest of the Universe is at our disposal and/or entertainment.

davidm

Thanks, Jobar. No, I think the thread can stay here. I was just pointing out that since you can debate fine-tuning without having to assume a fine-tuner, the discussion would then be about something other than existence of God. But seeing all these responses and new threads, I think the topic should stay here.

Several of those posting seem to say: (1) No one can speculate about what other universes would be like, or whether they would permit life, so the topic is meaningless; and (2) You can't think about likelihoods without a data set. I don't see why either conclusion is valid. I would again recommend the paper by Max Tegmark, who is a physicist. He does fiddle with the knobs and dials of our parameters and arrives at some very specific conclusions. He concludes that the vast range of universes with laws different from our own would not permit life of any conceivable kind to arise. His specificity is so great that he concludes, for example, that a universe consisting of one space dimension and three time dimensions would contain nothing but tachyons. If those posting have time to check out this paper, they might be able to put a new slant on this debate. I can think of several other new slants, as well. Maybe I'll start a new thread. Thanks again.

Synaesthesia

I would emphasize that it is no ‘random’ accident that our universe is structured the way it is. There is very good theoretical reason to think that there are unintelligent, non-random reasons for it being so. Since our universe has a non-random chance of existing, one of the central assumptions of fine tuning is broken.

That is, it may be that the empirical existence of the universe can tell us something about possible universes. What is not true is that any assumption about intelligent creation (or the importance of intelligence on earth) is at all justified.

The game isn’t a question of God or blind chance. It’s a question of wanting to feel at the center of the universe, or wanting to understand our place.

davidm,
According to the inflationary model, the dimensions didn't exist at the earliest stages of the universe. The number of dimensions was a state it stabilized into as it cooled and expanded. In short, his defense of FT brings to light it’s fascinating irrelevancy: The universe in which live in evidently has a non-random chance of occurring, but requires no designer to be that way.

echidna
The central assumption is that without design life is unlikely, with design it is likely and both hypotheses are otherwise equal. I reject this assumption. First of all, intelligent design has fundamental problems with it. (the evolution of the original intelligence etc.) Secondly, I reject the assumption that universes are of equal likelihood. There is strong indication, as I have been saying, that it is no accident that our universe it the way it is.

Given the absence of these assumptions, the fact that we exist tells us little about a designer. God must, as usual, rely on other, unspecified grounds.

Given the chemical and thermal composition and sheer size of the early earth, it is not incredibly improbable for molecules to form stable, even self-replicating systems. The principle has been proved in a lab, several self-replicating molecules have been synthesized. (It is unlikely that we have made the set of molecules which evolved into early life. There are many different kinds of self-replicating molecules!)

Life, however common it may be, will never constitute more than a miniscule portion of the universe because of it’s sensitivity to local conditions. That the annealed structure of our universe makes it stable is the reason life exists. Not only is it possible that the universe’s reason for being unrelated to intelligence, we have a theory about how this could be so! The same cannot be said of intelligent fine tuning hypothesis.

Regards,
Synaesthesia

davidm

Synaesthesia, it should be noted that Tegmark, in his paper, is NOT defending FT. He is putting forth, as I understand him, a scientific theory, one which he claims is falsifiable: That all mathematically possible universes are actually real universes. Most of these universes, he finds, would almost certainly be sterile for the reason that their essential properties would rule out ordered structures. He assumes that ordered structures of some kind would be a precondition for life of any kind.

If these universes do exist, FT is no problem, because observers would obviously only find themselves in those small range of universes that permit observers to exist. But what if they're not real? Then, FT might seem perplexing because it suggests that our universe took on a narrow range of properties permitting ordered structures when the vast range of properties it could have adopted would not permit ordered structures.

You say the universe is nonrandom, but my understanding has always been that the so-called symmetry breakings after the big bang were random and that the values we get for the laws we see were indeed products of chance. Have I misunderstood this? (I am definitely not a scientist.)

By the way, I don't think fine-tuning necessarily implies a fine-tuner, and I agree there is no evidence for such an entity. And even if the universe were fine-tuned in some way, there is no reason to think it was fine-tuned for us. What if we eliminated God and life from the picture? What if it's simply a case of a tiny number of universes with ordered structures vs. a large number of universes with no ordered structures? Would it seem strange that if our universe happened only once, it randomly took on that narrow value range permitting ordered structures? Or is the question somehow meaningless or misconceived? Maybe "random" means nothing in a one-time-only event? I think others and maybe you are suggesting the latter but I admit I have not yet grasped this point.

Jamie_L

Slightly off-track:

I don't really see a strong paradox in Fermi's paradox. The universe is big. The galaxy is big. And time is long.

The human race, as a civilization that is detectable by observers at interstellar distances, has existed for only a brief moment in time when compared to the age of the universe. And there's no guarantee that we'll continue to exist as such for long either (between nuclear weapons and highly-engineered bio-weapons, and all the nuts out there, our brains may out-do us yet).

Although it may be highly probable that many intelligent species will AT SOME POINT exist in this galaxy, there's no guarantee that they'll exist nearby and at the same time such that we can detect each other.

As for fine-tuning, my total layman's take is this: change any number of simple decisions over the course of my life, and I probably wouldn't be with my current wife. Is that evidence that we were "fine-tuned" to end up together. As I see it, no. But then again, as my wife sees it, yes.

Jamie

beausoleil

Fermi's 'paradox' isn't really a paradox. In short, it says that if there were intelligent life the evidence would be all around us. The argunent goes like this:

It is a reasonable extrapolation of our current technology that we could construct probes capable of travelling to the nearest star system, and that these probes on arrival could make further probes to explore further star systems. The first probes might reasonably be built within 200 years.

Such probes reach every star in the galaxy within a short time (compared to the age of the galaxy or that of the Earth).

There is no evidence of any such activity in our solar system, hence no technological civilisations comparable to our own have previously existed in the galaxy.

Perhaps the probability of intelligent life arising is so low that more than one per galaxy per 10 billion years (approx) is unfavoured. Or perhaps the first technological civilisation inevitably precludes the development of another in the same galaxy by colonising habitats before it can develop.
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Fine tuning arguments tend to one of two extremes. Each assumes that life can only exist in an extremely small subset of (as far as we know) possible universes.

Either this is the only universe and it was in some way designed for life (asserting that some principle ensures that the laws of physics turned out the way they did simply displaces the problem slightly, in a way analogous to 'who created God' arguments). Or there is a multiplicity of universes allowing at least one suitable for life to exist. The latter might be rolled in with various interpretations of wave function 'collapse' in quantum mechanics.

Neither is seen as very satisfactory, I think. One assumes a designer for which there is no other evidence, the other assumes a massive number of other universes for which there is no other evidence. But the alternative seems to be am incredible coincidence.
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It doesn't matter whether life getting started in geologic time is likely or unlikely - we can only be on a planet on which it did get started. By exactly the same principle that we can only exist in a universe with certain properties, but with a less troublesome population (multiple planets are more obviously verifiable than multiple universes).

[ June 13, 2002: Message edited by: beausoleil ]</p>