Order of Kilopi
Water may be liquid deep under the surface of Titan, where cosmic radiation wouldn't be a problem. The crust seems to be decoupled from the interior, sliding around over a liquid layer. This sort of movement or interior geological activity might provide energy to a biosphere rather than sunlight.Originally Posted by transreality
For now, of course, we just don't know.
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Titan might just be a block of dusty porous primordial ice 'out-gassing' methane through the cracks caused by tidal flexure. I'm skeptical we have evidence yet for any 5star hotels, let alone any movie stars.
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Yes, there is. If intelligent ET life were common we would see evidence of it everywhere. In fact, we probably would've been born into subservience of such life rather than randomly evolved in a lonely corner of the universe.
But that anthropomorphic line is a little philosphical and not my main point anyway. The main point is based on the observation of how quickly human intelligence is developing, on geological time scales. For God's sake man we have only been writing words for 4,000 years. If you have any hope for our ability to one day bridge the vast gap between star systems, do you think we could do it in 100 million years?
And if you can spread successfully from one star system to another, you could spread to many many star systems. So if civilizations like our's were common, that is to say INTELLIGENT life, would it not be common for some of those civilizations to last millions of years and spread through hundreds, thousands, millions of worlds?
Would that not reveal some sort of evidence? Any sort of evidence? We clearly have had an impact on the Earth. Someone observing our solar system (not even saying that have to be doing it from another star) would clearly see the impact of intelligent life on this planet's surface. So why would we not see evidence of intelligent life throughout the galaxy if it were, as you say, "common"?
These potential civilizations have had billions of years to appear.
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What evidence would an Amazonian tribesman see if he walked out of the rainforest to a city? Structures, cars, airplanes, huts, lighthouses, soldiers. If life like our's were common then galactic conquest would be common and they would've already come to this system to harvest the sun's energy.
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Not true. We have a lot of evidence about what is going on in this galaxy. We have billions of years of fossil records here on Earth. They show us what species lived here, what the chemical constituents of our atmosphere were like, when we were struck by meteors. All of the Earth's history is evidence about the galaxy because the Earth is part of the galaxy.
We don't have to build a telescope so strong as to see extrasolar planets to make some conclusions about the galaxy, because we have the history of the Earth to go on. The fact that there is no evidence of galactic civilization in the billion year history of Earth is a pretty strong argument that galactic civilization is simply not out there, because civilizations like our's would have spread out to make use of available resources over the course of millions of years if they were anywhere near here.
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I'm not sure that your argument was well put or compellingly laid out, but I tend to agree with the overall premise.
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Let me point out the error in this reasoning, from your own words
This sounds like evidence that interstellar travel is not possible, not evidence that ET life is uncommon.
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It would only take civilization one per, say, every ten galaxies to make intelligent life common in the universe, as well as making each extremely isolated, perhaps permanently. So, ET intelligence could be common, but no evidence would be forthcoming.
These potential civilizations have had billions of years to appear.[/QUOTE]... The main point is based on the observation of how quickly human intelligence is developing, on geological time scales. For God's sake man we have only been writing words for 4,000 years. If you have any hope for our ability to one day bridge the vast gap between star systems, do you think we could do it in 100 million years?
And if you can spread successfully from one star system to another, you could spread to many many star systems. So if civilizations like our's were common, that is to say INTELLIGENT life, would it not be common for some of those civilizations to last millions of years and spread through hundreds, thousands, millions of worlds?
Would that not reveal some sort of evidence? Any sort of evidence? We clearly have had an impact on the Earth. Someone observing our solar system (not even saying that have to be doing it from another star) would clearly see the impact of intelligent life on this planet's surface. So why would we not see evidence of intelligent life throughout the galaxy if it were, as you say, "common"?
In the Milky Way galaxy, correct that we have seen no evidence for species nor machines to have undertaken the kind of expansion we assume would take place. It may be that science and technology overcome the need for expanding resources, and reproduction rates are low in a given society, which would allow for them to precede us yet be in our galaxy without expanding into our neighborhood. Mass extinctions, self-induced or natural, may severely limit the lifespan of intelligent societies. We are not so immune ourselves on that front, and still being here is no indication of savvy, only luck.
Or maybe we are the first. But by the Copernican principle, my take is that there is nothing at all unique about Earth, and the Goldilocks conditions life has required here are not prohibitively stringent, so no reason to doubt there's life out there somewhere, and in places telling jokes.
Calm down, have some dip. - George Carlin
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Disagree.
What is intelligent life? Certainly life forms that are less "intelligent" than homo sapiens, circa 2010. You make a huge sci-fi leap in asserting that intelligent life is capable of traveling from star to star. Where is the proof? We can't do it and show no trend line than suggests that we will anytime soon. The allocation of resources towards this aim is not worth the tradeoff in the minds of most (or at least the "decision makers" within this population of "intelligent life").
Who says that intelligent life will have lifespan of millions of years? Homo sapiens are at ~ 200,000. Extinction events happen all the time as the universe is a dangerous place in the long run.
I'd say that the odds are exceedingly remote that "intelligent" life forms ever travel great interstellar distances or survive more than a few million years.
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Possibly, though there is no technical reason known prohibiting interstellar travel, at least none that I'm aware of.
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uh, hmm, what? One civilization for every ten galaxies? That would make intelligent life SPECTACULARLY UN-common. Would it not?
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There is a trend, and i'm giving us geological time scales. We've only been "intelligent" for maybe 10k years or so, and most of our leaps coming in the last 2k years. If we extrapolate this trend out to 100k it seems we could make a craft capable of spreading humans to other systems. I will grant you the future is hard to predict and the task is gargantuan to say the least, but i'd say more likely than not we are bound to do this.
What would kill them? You have to get pretty serious catastrophes to wipe out an entire species. Asteroid impact leading to a thousand years of volcanism? That only happens here on Earth about once in 100 million years. And nothing in the 4 billion year history of Earth has ever wiped out ALL life here. And that's considering only life not intelligent enough to engineer its own survival. Once these intelligent beings reach a certain level of technology, they should be able to foresee and prevent most catastrophes, particularly ones serious enough to threaten their entire survival as a species. We humans are now on the cusp of this technology level where we might actually be able to do something to save ourselves if we knew a vast period of volcanism was eminent.
Imagine what would happen if the Chixulub event happened today. It would be devastating to say the least but would it extinct us? Perhaps the ensuing volcanism would create sulphuric compounds that destroy the root of the food-chain with plankton and algae in the sea and such. Unlike the dinosaurs, we humans would be smart enough to understand why we were dying and possibly engineer our own food and maybe have 0.001% of the population survive to preserve the knowledge and DNA of our golden age.
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Well, there are the extremely prohibitive energy requirements.
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Define common.
If there are 100 billion galaxies in the universe (very conservative estimate), then that's 10 billion civilizations.
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What is the ratio of energy used by our civilization today vs. energy used by it 1,000 years ago? Are there not widely available sources of energy such as the Sun to be harvested?
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I would not even consider other galaxies in the question of "how common is intelligent E.T.?" since the Milky Way contains several hundred billion stars. It's a big enough sample for this question. When Jeff Root said he felt intelligent life was "common" I presumed he meant something on the order of a hundred million civilizations in the milky way, which would amount to a ratio of 1 in every 5,000 stars.
Maybe Jeff Root can also provide his definition of common.
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Do you think it's wise to extrapolate like that? Do you think the human population will be over 1 trillion in 1000 years? Will computing power be quintillions of times (or more) faster in 1000 years?
Even so, there are far more problems with interstellar travel than the power requirements. In fact, I would suggest that the Fermi Paradox indirectly dictates that you can you have common ET life or interstellar travel, but not both. At this point, the odds are leaning heavily against interstellar travel.
Correct. This is the problem when people use imprecise terms and then assign different meanings to me. I agree that all that really matters in the ET discussion is the chances within this galaxy.
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Not sure about some of those things, but I do think inter-stellar travel is a reasonable extrapolation of our technological progress as a civilization. Computing power could well be millions of times more powerful in 1,000 years and that could go a long way to designing successful inter-stellar missions.
I bet that Columbus and Magellan had a lot of smart guys tell them the same thing about journeying around the globe, and i bet Sir Edmund Hillary heard a lot of this sentiment too when he proposed to climb Mount Everest. I know that interstellar travel is WAY harder than either of these two things, but there is something in the human spirit that strives to meet such challenges and if you give us 1,000 or even 100,000 years, I say we get it done. These are not huge amounts of time in the history of the galaxy.
For this reason I believe the Fermi Paradox is explained more by lack of intelligent life than the difficulty of interstellar migration.
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If there is a lack of intelligent life, it can also be explained not by its unlikeliness, but by its self-destructiveness.
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This has drifted somewhat away from the OP... So to return some way to that...
Evidence for ET is NOT mounting, but the chance of us detecting it is getting better. Making no assumption that its there to be found...
A certainty of likelihoods dose not confirm science fact. We keep looking. We get better at it. Waiting for that one detection event still and patently...
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There's the rub - I very much doubt we have 1,000 years, at least not in our current civilisation. If humankind is anything to go by, increasing technological advancement also brings increasing self-destructiveness (especially as we show no signs, as a species, of growing out of religion). I think we'll be doing well to get to 2100 without a major setback.
Order of Kilopi
You're suggesting, in exploring the cosmos, earthlings have "walked out of the rainforest?" I don't think so. At best, we, as "tribesmen," have ventured only a little ways up and down the nearby river and climbed the highest trees for a better vantage.
Would they? Why not some other more energetic star instead?If life like our's were common then galactic conquest would be common and they would've already come to this system to harvest the sun's energy.
And leaving aside the difficulty of interstellar travel would we know astroengineering if we saw it, from near or afar?
Don't get me wrong, I don't dismiss out of hand that we should already be part of a galactic civilization a la "zoo hypotheses." I just don't think we'd necessarily know it.
Where the telescope ends, the microscope begins. Which of the two has the greater view?
Order of Kilopi
Indeed, any Type II civ, as Toonces suggests, would've had to overcome species self destruction; "conquest" mentality is part of that.
Where the telescope ends, the microscope begins. Which of the two has the greater view?
Order of Kilopi
Double speak.
If no assumption it is there, then why are we looking, improving our methods for and chance of, detecting it?
Right, only alive ET life will constitute evidence for ET life, nevermind every other "likelihood" that it is there.A certainty of likelihoods dose not confirm science fact. We keep looking. We get better at it. Waiting for that one detection event still and patently...
Where the telescope ends, the microscope begins. Which of the two has the greater view?
Order of Kilopi
Only an extremely tiny part of the galaxy. Our evidence about what is from outside our Solar System is exceedingly limited. We have yet to observe a single comet from outside our own Oort Cloud, much less discovered the remains of one. All of those meteors were from our own Solar System.
No. You are making an extremely strong presumption about what a galactic civilization must be like and what it must do if it exists. In fact, even a civilization like our's has not spread out to make use of all available resources. How much of the ocean floor have we colonized? We have spread out where we have wanted to spread out. We have not spread out everywhere, for various reasons.The fact that there is no evidence of galactic civilization in the billion year history of Earth is a pretty strong argument that galactic civilization is simply not out there, because civilizations like our's would have spread out to make use of available resources over the course of millions of years if they were anywhere near here.
There could indeed be a galactic civilization out there, and if it exists there is no a priori reason to assume it is like our own. Even if it is like our own, there is no a priori reason to assume it would find our solar system desirable.
For example, maybe they prefer white dwarf systems. Unlike Sun-like stars, these are stable on trillion-year timescales, provide convenient throttle-able power, and don't emit annoying flares. A Dyson sphere style power system would require many orders of magnitude less mass due to the smaller size. Heck, these aliens might already have their eyes on the Sun--they're just waiting for it to turn itself into a white dwarf in a few billion years. In the meantime, there's no shortage of existing white dwarfs in the galaxy.
That's just one example. We simply don't know what an alien galactic civilization would be after. There are all sorts of possibilities. Some possibilities include extensive obvious exploitation of our specific Solar System. Other possibilities do not.
Order of Kilopi
Nitpick: Earlier this year it was announced that the best known comets may be extrasolar in origin.
The other day was: Sun Stole Comets from Other Stars.
None the less I certainly agree our evidence is limited.
Where the telescope ends, the microscope begins. Which of the two has the greater view?
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I disagree with this. We've had a lot of wars and destructive behavior over the last 4 thousand years, but overall it hasn't stopped the flow of intelligent civilization towards mastery of nature.
There are a LOT of things that can set us back. But there aren't a lot that completely wipe us out. So to say we "don't have 1000 years" i think is a gross underestimation of our species's life expectancy.
You also say that increasing technological advancement brings increasing self-destructiveness but... hasn't the Earth actually been more peaceful since the invention of the atomic bomb?
Even WWII didn't nearly wipe us out. In fact it led to a lot of scientific advancement.
Religion doesn't matter. It won't stop the progress of science either.
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There's a very important reason for this, embedded in your next paragraph.
That's where you miss the point. For 4000 years, technology has not provided mankind the power to "completely wipe us out." We have only recently reached that threshold.. not just militarily, but in our ability to affect the environment.There are a LOT of things that can set us back. But there aren't a lot that completely wipe us out. So to say we "don't have 1000 years" i think is a gross underestimation of our species's life expectancy.
The atomic bomb has changed the balance of power, but technology has greatly increased the lethality of conventional warfare since its inception.You also say that increasing technological advancement brings increasing self-destructiveness but... hasn't the Earth actually been more peaceful since the invention of the atomic bomb?
Wars are still raging and the ability to wage them safely from a distance, thanks to technology, has only prolonged them.
Do you realize that we were literally on the verge of a nuclear holocaust in the mid-80s? The Soviets were one man's decision away from pushing the buttons in response to a perceived nuclear assault (thanks to an error provided by technology) and he chose to not do so.Even WWII didn't nearly wipe us out. In fact it led to a lot of scientific advancement.
The Dark Ages set the progress of science back 1000 years or so.Religion doesn't matter. It won't stop the progress of science either.
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there's a lot wrong with your post baric. first off the Dark Ages were a European phenomenon and science progressed in the middle east during that era which is why we have "algebra" and "arabic numerals" and also a lot of arabic astronomical names. Secondly how close we were to nuclear holocaust during the 80s or the CMC is debatable and nuclear holocaust would not have wiped us out completely or destroyed our knowledge of science. You seem to be suggesting we will kill ourselves through our own technology but do you have any real example of that? To me, self-inflicted wounds from technology are a limiting factor, not a "wipe us out" factor, and when you look at the other side of the technology coin which is the vast improvement to our ability to survive it renders your argument a little useless.
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You are correct that science did progress in the Dark Ages, but much of it was halting and recovering what had been thrown away by the Romans. But will you not also concede that much was lost during that process? Archimedes was dabbling with calculus before the fall of the Roman Empire and it was not formally defined until 1000 years later.
And keep in mind that the "Renaissance" relied heavily on the Greek texts that were written before the Dark Ages.
You ask for the absurd since we are still obviously here. However, I will give you a simple example wherein in one individual made a judgment call that essentially prevented a nuclear war between the US and the Soviets: http://en.wikipedia.org/wiki/Stanislav_PetrovSecondly how close we were to nuclear holocaust during the 80s or the CMC is debatable and nuclear holocaust would not have wiped us out completely or destroyed our knowledge of science. You seem to be suggesting we will kill ourselves through our own technology but do you have any real example of that?
Think about the ramifications of that incident and then honestly tell me that you don't think we are capable destroying much of what we have built up in a short amount of time.
We can undoubtedly survive as a species. But as a technological civilization? That's a different story and frankly the only one that matters if you want to discuss us being able to travel across the stars after thousands of years of technological advancement.To me, self-inflicted wounds from technology are a limiting factor, not a "wipe us out" factor, and when you look at the other side of the technology coin which is the vast improvement to our ability to survive it renders your argument a little useless.
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