Why we're the only intelligent life in our galaxy

The scenarios are not presented as mutually exclusive, but the arguments are. If you assert Earth-like life elsewhere, you fall prey to Rare Earth arguments. Rare Earth arguments are often mathematically intensive, and those waving them away are often far less rigorous, and often complete lay people. I have not seen a rigorous refutation of Rare Earth papers by anyone in these forum. Thus, since they cannot refute the former, they fall back on the latter. The discussion of non-human-like life is marred by the complete inability of any of them to propose a working hypothetical example of such a system and what conditions would be needed for it to arrise ab initio. Many of those in the forum ride the fence because they keep getting bounced from side to side by the far more rigorous arguments about the difficulty of life arrising.

What is there to discuss? Saying it is a "gray area" handwaves away all sorts of basic definitional problems. How can you even assert that alien life elsewhere (ETIs) exists or doesn't exist if you can't even define what an ETI would be. The reason we discuss Earth similar and human-similar concepts is because we have a basis for discussion.

If you want to discuss ETIs, then first define what an ETI is, what substrate it operates on, etc.

I could state that there are Pink Elephants elsewhere in the universe, yet if I never define what a Pink Elephant is, what point is there to intelligent discussion?

Yes, this all boils down to the sci-fi dreamers, who want the universe to be teaming with interstellar civilizations, starships, and other junk. But if they want to argue that their hopes and dreams are realized in the real world, they better be prepared to be more specific about what they are discussion.

Frankly, if this discussion is about "what if pigs could fly" and not "Proof that pigs can't/could fly", I don't want a part of it. What does "ephemeral" mean? You mean, free of content, vague handwaving ill-defined concepts passed around as argument? It's bogus and does nothing to refute Chalnoth's very specific assertions.

If you can't refute Rare Earth, then don't try to bring in "ephemeral" red herrings. Chalnoth started with a more logical/scientific discussion. Create a new thread if you want to discuss "in principal, ephermal pigs could fly"

 

Demo a lot of talk, but at the end of it - even though you state they are mutually exclusive - that does not make it so. Let me ask you straight, so there's no confusion - and please answer this question regardless in your next post: Do you think it's impossible that there might be another human-like intelligence out there, and at the same time another non-human-like intelligence as well?

Frankly in my opinion being unable to propose a working theory on how such non-human-like intelligence could arise is not a big concern of mine; I content myself to know that I do not know all that there is to know in terms of the universe's physical laws. In days gone my, no one would have been able to explain why the Earth is round, and I could see a DemoCoder of that day as having been one of the most ardent critics of such a theory. Think about that because you truly seem willing only to operate based on known quantities. It's the same as the deep sea life example I used earlier in the thread; most of the scientific community were previously against the idea, and had many a good reason why such could not exist. Then, they actually find it, and the theories for why it actually can exist begin to emerge.

Do I believe in god? No. But it is a similar thing here that we are discussing, in that we are talking about the inherently foreign. If there *is* a god, I readily admit that I cannot in my present state understand 'him.' By the same token, although I do not beieve in one, I cannot as a rational being rule out the possibility of his existence, since by it's very definition would such an understanding be beyond me anyway, and it cannot be proven one way or the other. In a manner exceeding this infentesimally small chance I am granting to the existence of a 'divine' being, am I also allowing for non-terrestial-like alien life. You keep mentioning 'rigorous' debate, but honestly it just seems like you're unwilling to leave your comfort zone of absolutes. You want to define what life is for terms and context of this debate? That's fne with me, but let's start with viruses - are they life? When even that question has no solid answer, why are we wasting time with semantics on alien life?

 

You can't prove a negative. I have never stated the impossibility of alien life. I think simultaneous (as in, they both exist right now) earth-like human-level life is improbable. Not impossible, improbable. This is in contrast to those who wave around arguments like "but but, the universe is so big, there must be a very high chance of alien civilizations elsewhere"

As for completely alien life, as in, not DNA based, but based on an as yet, unknown process, the question is so open ended that one cannot argue it one way or another. Thus, any arguments that begin with "the universe is so big, other weird forms of intelligent alien life *have* to have evolved else where" are fallacious. One can make a conclusion one way or the other.

If you break the question down to a) self replicating molecular life b) life based on rearrangements other than chemical, then one must propose a mechanism by which atleast trivial computations can be carried out. (e.g. rod-logic computing) and how that would arise ab initio, what's its energy source, waste transport, etc.

Since you are not willing to have this particular discussion, and since you can offer zero details on non-earth-like lifeform intelligence, any assertions you make about the probability of such life existing have no support and must be retracted.

This is not a discussion of what can exist in principal. No one has ever claimed that life processes cannot occur in another substrate. In fact, I am an overwhelming believer that in fact, it *CAN* happen in another substrate, and this is what will allow transhumans, post-humans, and artificial intelligences to exist. The question isn't one of "what's possible in principal", it's showing that what's possible in principle is possible in reality, and to do that, one must overcome critical arguments to the contrary as well as showing *how* it could be true.

You are neccessarily unwilling to do this. If you came to me and said "The earth could be round!", and I believed the earth was flat. I would not say "impossible!". I would say, "how can a planet be round? what kinds of physics or processes might contribute to spheroid shape?" People millenia ago were able to provide such evidence, even before we had telescopes or gravitation. So it is not unreasonable to ask.

What is unreasonable is for someone to try and engage in a "debate" and when asked for arguments to back up his position, he just waves his arms and say "well, the definition of 'round' is ephemeral. I can't tell you what it is, and i can't tell you how something can be become round, or what round things are. I just KNOW that the probability of something out there being round is very high."

There are lots of things in history for which we thought there would a high probability of existence, and which ended up NOT existing.

People's intuitions are commonly wrong.

 

So we're on the same page then.

We're still on the same page.

If the question were broken down to that level, I agree - but the the thread title sets the stage for discussion, and that discussion is soley why we *are* or possibly *are not* the only intelligent life in the galaxy. Now, that sort of absolute statement was maybe a bad way to get the thread started, but it nonetheless sets up a situation where the two sides are those saying that other intelligent life does not exist, and those saying it might. Not that it does, that it might. And to that effect, when I myself was presenting the life based on different elements thing, I wasn't trying to pursue it so much as to present this situation:

If the chances of Earth-similar carbon life are greater than zero

and

If the chances of non-Earth-similar life are also greater than zero

...then the acknowledgement of that is by it's nature an acknowledgement that the chances of intelligent extraterrestial life are greater than our present understanding of the universe would allow us to determine. Now, an assumption is made with the later of course, because like a microcosm of this entire debate, we can't prove the non-similar possibilities one way or the other at this time, whereas we know life based on carbon has an incidence rate of at least... well whatever unit we would attribute to Earth's own situation.

Well, I explain why I do so above, and won't retract.

What is a discussionof then, if it's not a discussion of what could exist in principal? The thread makes the assertion that 'other intelligent life in the galaxy does not exist.' I contend that the logic behind such a solid assertion is flawed.

It was just an example, take it for what it was. I maintain that you probably would come out of whatever discussion thinking the worl was flat, and that the 'lay people' had it wrong. By the way that's kind of an ironic term to use considering your disdain for all sorts of religion, whether organized or personal.

If you feel my arguments have not been backing up my position, then either you donot understand my position or we simply disagree on that point. What do you think my position is?

 

Im still not entirely satisfied with the premise that a civilization

1) Wants to colonize immediately on such short timeframes, rather than waiting until its existance is in jeopardy. Consider that building a colonization taskforce is a massively destructive operation on your host planet.

2) Will ever be able to colonize (say the physics is impossible)

3) Doesn't go extinct before it gets the chance.

4) Focuses on planetary colonization. Ultimately if it comes down to it, all you need is renewable energy and material abundances. Stars are a good place to find heavy elements, but they are by no means exclusive. There is plenty of ejected materials floating around in the ISM that it might make such an endeavour pointless. This would be disastrous for the theory, b/c the exponential growth would no longer occur. People would float around in essentially one large spacecraft gathering resources and so forth.

 

Most of the predictions for alien colonization don't necessarily assume that a biological civilization goes about constructing biospheres or artificial biospheres on other planets, and settling as we would settle from Europe to the New World. That's the Star Trek "M Class Planet + Colonist" fantasy.

Rather, the implicit assumption is that interstellar colonialization happens "virtually" by sending out self reproducing Von Neumann machines, which use local resources as they travel to build more and more base structures. (not unlike Mars Direct by the way) There are then two options:

Option 1) the biological beings then leave their home planet via ships, go into deep sleep, or just live and die for generations on ships until they reach the prebuilt bases. (the ships would probably be build by Von Neumann machines that consume materials from the rest of the solar system, NOT the home planet)

Option 2) the bases that get built run virtual environments, or come with prebuilt android bodies. The biological beings then "leave" their home planet via uploading, whereby they either a) copy their mind into a form which can be transmitted as information and leave their bodies to die or b) they create "offspring" which is non-biological, their "Mind Children" so-to-speak, which go out to the universe to explore why they sit on the home planet until the "end comes"

Advanced civilizations are assumed to include immortal beings, for whom travel times, may be irrelevent, either because they are artificial and can travel virtually, or simply because they can "switch off" and thereby travel in subjective time, running their consciousness very slow.

Even if you don't believe the idea that "consciousness" can be hosted on something other than DNA biology, advanced alien civilizations could "reverse colonize" by sending our self replicating robot probes which scour the universe, record it in detail, and transmit the information back to them, so that they make "travel" to foreign lands by knowledge acquisition. One can explore without *physically exploring yourself* as demonstrated by NASA probes today. Such probes could also bring necessarily materials back to the home solar system to extend resource limits if needed. Yes, this happens over extreme time spans, but one must assume that alien civilizations will exist practically until their planet is no longer suitable.

(I won't get into the consciousness on non-DNA subtrate debate. To be frank, many physicists who have no expertise in molecular biology and neurology frequently make such assertions, including absurd Penrosian assertions that consciousness requires quantum gravity and is based on leveraging the 4-manifold classification problem, which is inherently undecidable, and thus non-computable)

 

And that is why your example is flawed. Your example assumes life was born through a random sequence of events. We do not know this and assuming it is the "only way" is naive. That is also why Chalnoth's argument is doomed to fail ie "Other highly intelligent lifeforms likely don't exist because if they did they would be here and we would already be gone". If they exist how do we know their pupose, needs, motives etc? We cannot assume everything is based on "our way".

 

Yes, we do not assume that the Great Spaghetti Monster intelligently designed the universe or its inhabitants. Because such assumptions remove you from the realm of science and logic and cast you into the realm of faith. They cannot be falsified, and there are an infinite number of such theories, depending on who your deity is and what he was supposed to do. You also can't disprove we're not living in a giant computer simulation, or that the universe sits on the back of a Giant Turtle. (well, either that, or you've watched pan-spermia based episodes of Trek, Star Gate SG-1, or Babylon-5 and buy into another variation on supreme (ly advanced) being(s) seeding life. Just another variation on intelligent design.)


My example is certainly not wrong, since it is meant to show that if you make the argument that the size and age of the universe *guarantees* many many civilizations arising by sheer statistics, then you need to brush up on your mathematics, because as I explained, an infinite number of trials of a process does not neccessarily produce a specific result, or produce it more than once.

People alot smarter than you have gone threow the Fermi Paradox argument before (including, if your name NANOTEC is any indication, K. Eric Drexler, the founder of Nanotechnology). It's not Chalnoth's argument. We don't need to assume "our way", but if life is as common as the dreamers would like to believe (e.g. people who put credence in garbage-in-garbage-out Drake equation figures), then it is extremely probable that it is *very very old* compared to our civilization, so if the universe is teeming with millions of very advanced and old civilizations (we're talking millions or billions of years more advanced) one would have to wonder why atleast one of them has produced a detectable signal or did some significant stellar engineering work. The idea of simultaneous evolution of civilizations that are merely a few hundred or thousand years older than our civilization is exceedingly improbable.

This then leads into a bit of reverse assumptions by the dreamers "well, what if all civilizations die off before they do this, or what if the all decide not to colonize, or what if they all decide to hide themselves from view" all to explain the Great Silence, because if you accept their assumption that the universe is practically jam-packed with life, one has to explain how all civilizations everywhere fail to do what is practically necessary to have a civilization in the first place: expand.

 

Why do large numbers alone convince people of the unlikley? There are a shitload of atoms on planet earth, but they don't split and cause nuclear reactions without a specefic chain of events taking place. Evolution needs that same series of events to occur. Indeed, life may be quite common, but intelligent life, far less so.

 

From reading your "argument" it seems you cannot debate without laughing at an opposing view. You act like a "know it all" using "science" as some kind of gospel that can explain everything in the universe. A few hundread years ago "science" thought other planets revolved around the earth. Science is just a tool create by us, it's not a solution or an answer to everything and it has been wrong many many times. This guy was laughing too. http://www.beyond3d.com/forum/showthread.php?t=30095

I don't recall anyone here claiming many many civilizations are guaranteed to exist or have existed. The claim was that since we exist it is likely that others also exist. Using math to disprove this is futile since you have yet to prove life on earth is the result of a random sequence of events

I'm not sure where my intelligence came into question, but if you need that as a crutch for your argument then go for it. What I see is you accepting an idea from people you believe is smarter without coming up with your own argument. Smarter people are just a group of people, products of this human race, but somehow you worship them like some intellectual god and their word becomes gospel with nothing to back it up. Their theories are just one among a list of theories created by us, none of which really answers the question, hence why it's called a theory.

If the claim was that there are millions of other intelligent life capable of contact, then sure it woulld be difficult to explain this Great Silence, but who is claiming there are millions of other intelligent life capable of space travel? Maybe there are none, maybe there are a handful? Maybe they haven't found a way to survive long enough for the journey? Maybe there are only handful and none of them care?

This assumes life as we know it evolved from a seires of natural events which we don't know for certain.

 

Even if we assume life here on earth was a result of random natural events, some of ideas I proposed still cannot be answered. For example maybe there are only a handful of intelligent life on other planets that are capable of space travel due reasons that do not apply to our own race? You cannot scientifically discard these possibilites. That's just one example out of many that I can come up with to explain the Great Silence.

 

Well, I laugh at people like you who bungle their arguments because apparently, they can't think rationally about large numbers. For example,

Whilest simultaneously attacking the view that life on Earth started by abiogenesis, you bring up the number of stars in our galaxy. If life on earth was seeded by advanced species, than the number of stars in the galaxy is mostly irrelevent, since they'd only need to find one candidate planet to conduct experiments on.

The only time the sheer size of the galaxy is relevent is if you want to discuss the probability that intelligent life arises naturally on other planets, but if that were your goal, your assertion that 200 billion is neccessary and sufficient to make certainty claims is quite laughable. You even seem to think that 200 billion is a large number "I think from that number alone..." as if 200 billion were such an impressive number, that nothing more needs to be said.

You don't like the fact that I called you on your lack of rigor and understanding of the numbers involved, and pointing out that large numbers of trials don't necessarily guarantee anything is just a trivial example of how your assertions break down.

(idiotic attacks on science deleted. )

Define "likely". If you try to work out the "likelihood" of life elsewhere existing given observed evidence that earth exists according to standard probabilistic inferencing, you end up with a tautology that says you can't conclude the likelihood without knowing the likelihood of earth existing, given other planets existing (essentially what an Alien B3D forum debate would be asking) It's circular, and no conclusion can be made.

It can't be proven. One can only disprove a theory, one can never prove a theory. You can't even prove the sun will rise tommorow.

You almost sound like a Christian fundamentalist zealot when they sneer "evolution is just a theory". The fact that there are many theories doesn't say anything about the distribution of correct, inconsistent, or flat out bogus theories. And then there is YOUR theory, which is not a theory at all, since it can't be tested.

Any other model simple isn't scientific. Then you get into intelligent designer theories, whether deity or sufficiently advanced alien, which can be ruled out at this point of time due to Occams Razor and lack of evidence. Maybe Earth was built by a race of hyperintelligent six dimensional mice to calculate the answer to the ultimate question of life, the universe, and everything. But there is no obvious evidence that such a theory is needed, nor any data that supports it.

 

And what if pigs could fly. And what if there was exactly one other hyperadvanced species, but they all got addicted to bowling, and ended up turning their whole planet into a bowling alley, where they spend all their time. You could generate a bazillion of such explanation, because with suitable mental masturbation, you can backfit any data with a sufficiently silly set of possibilities.

This line of argumentation leads no where. Any arguments about ETIs must procede from some assumptions as to their behavior based on assumed global invariants. Consider Marvin Minsky's argument for why we would be able to communicate with ETIs You could argue that ETIs could simply be inscrutable, speak languages simply beyond the Chomsky hierarchy, with no way to share concepts at ALL. But it's a handwave. The example of Minsky is to show how certain ideas may be universal if any species needs to survive and become a space faring civilization.

All you are doing NANOTEC is engaging in mental jerk off. You are not proposing any assumptions, and then reasoning from there (except for bogus assumptions like 200 billion stars implies degree of certainty of life elsewhere). Instead, you are just proposing an endless stream of possibilities, not of which can even be calculated.

At the very least, if you plug all of your hypothesis into a Bayesian Inference calculation along with the Rare Earth hypothesis, you might be able to calculate whether one should have stronger or weaker belief in Rare Earth given your scenarios.

 

In that case, the argument must also account for the immense difficulties in traversing interstellar space or finding valid reasons for colonising planets rather than just building "houses in space" to then use the numbers to suggest that we are the only intelligence within our galaxy. So far I've not seen any decent explanation as to how all of the problems could be solved (I don't mean in this thread, I mean seen within scientific journals) or at the very least, why they are a less significant collection of variables than the numbers game.

 

Where did I claim life on earth started a certain way? Where did I say it was started by other life forms? All I said was that science has yet to prove life came to be as a result of random natural events.

200 billion can be a large number or a small number depending on what you use as the basis for your argument. My basis is "what we don't know". The fact we discover something new everyday should hint at the things we don't yet know.

The numbers may/may not mean anything unless you can prove life was born from a random sequence of natural events. Can you prove this? No.

I define likely as at least one intelligent species exist in our own galaxy. I don't make any claims to their timeframe of existence or their capabilities.

Well then you cannot say it is accurate or not. It's just an arbitrary idea, built up from things that "make sense" to us as a human race.

Well the irony here is that I'm not a religious person and follow no religion. I'm more of a science guy, but I'm not so naive to believe that science can explain everything or that our limited use for science can either.

Scientific models are based on ideas, some can bre tested some can't. Maybe someday science can explain how life actually came to be on earth, but to restrict it to some sequence of random natural events with no scientific basis puts it on the same level pink elephants. Heck pink elephants (albinos) might be closer to reality than cells in the ocean transforming into humans through millions of years of random events.

 

I don't think anyone is arguing that science can provide all the answers at this point in time. Science (as you've pointed out) is a tool devised by man, and it's understanding of the world is incomplete. No scientist would argue against that.

But science was invented for a reason -- that being that it's the most efficient and effective mechanism so far devised of answering questions about the world (short of simply making the answers up!).

So having invented the tool it's just a bit silly to chuck it out of the window when the answers it gives aren't the answers you want. Science doesn't deliver a galaxy teeming with life, so science must be wrong. Science must be incomplete. There must be something that science hasn't thought of. That is where the religious aspect comes in ... it's no different from the efforts of the fundies to prove that God exists using "scientific" arguments -- when science doesn't give them the answer they want they resort to "yeah, but science isn't finished ... and Flat Earth and stuff".

So basically ... science, either accept and acknowledge it's flaws but see what it has to tell you, or ignore it and accept that you have a faith-based world view. There's not really a half-way house.

Errr.... no, the point of a scientific model is precisely that it makes predictions which can tested against observables.

 

I don't see it as "if it's not this then it has to be that". That is a very ignorant way of looking at things. My thought process is more of "If it's not this then the possibility exist that maybe we don't understand enough to say what it is".

And that was my point, it makes "predictions" aka "a guess" based on what is "observable". What about the things that can't be observed? Isn't that half the equation? Even then it's only things we can observe within out own self developed methods. Also observing is one thing, explaining is another.