Deep spacers can find us whether we radio them or not and. I imagine, they also would prefer to mine resources in smaller bodies - gravity wells are huge resource consumers.
It's not very likely they would like to touch the Earth when there is so much water, carbon and miscellaneous metals on the Oort cloud for the cost of towing them into your processing facility. It also spares them the need to enter lower orbits around the Sun. We don't see it as a gravity well because we are at its bottom, but if a deep spacer could choose, he would probably not enter it.
I suspect that sufficiently advanced deep spacers who intend to remain undetected, can. I also suspect that many races will conclude that this is the best strategy for long term survival.
Any spacefaring nation with propulsion technology sufficiently powerful that interstellar voyages are feasible... basically have technology that can sterilize planets. It's called "pointing the drive in the wrong direction."
Hopefully, any spacefaring nation smart enough to develop sufficiently powerful propulsion is also smart enough not to casually commit xenocide with it. Given our own track record, though, that's a pretty freaking big "hopefully."
In all seriousness, the possibility of harmful alien contact is quite real and should be taken into consideration by the scientific community. That said, I think it's much more important (and hopefully covered in the new documentary series) to concern ourselves with our behavior as we venture out into the Universe and seek new territory and resources. I mean knowledge.
I think he's thinking along the lines of Charles Pellegrino in _The Killing Star_. When we can command the technology and the vast energies it would take to travel to other stars, wiping out planetary or solar-system wide civilizations in a single bombardment becomes relatively easy.
Other starfaring intlligences may well decide to do unto us before we do unto them.
You could do it with 1960s computers and whatever Sci-fi Magic propulsion system your probe needs to get from system to system. Find a big asteroid. Accelerate it into the orbit of the planet at, oh, .01c should be plenty. What is the planet going to do, roll a natural twenty to dodge?
In _The Killing Star_ advance probes locate almost every settlement in the Solar System and every one is hit with relativistic projectiles. Earth itself is blanketed with an entire grid of such impactors -- from opposite directions, so the whole surface is bombarded. 99.9% of humanity dies in the space of several hours.
Since the projectiles are relativistic, there is no warning.
There's no conventional or nuclear way to generate enough directed energy to push a decently sized asteroid, on a straight course for the planet and within a reasonable distance of it, away.
An asteroid with a diameter of 2 km and a density of 1 ton/m^3 weighs ~410^9 kg. Travelling at 0.01c, it has a kinetic energy of ~410^22 J, or ~100 times the current worldwide energy production per year.
Of course deflecting it doesn't require you to fully stop it, but it's closing in fast and you need a strong sideways push to accelerate it fast enough to end up with enough speed to miss the planet. If we ever see an reasonably sized asteroid with reasonable speed on a collision course, we're as doomed as if we hadn't seen it.
Actually there is - like most technology it all scales up, and if it happens you bet we'd all be in factories churning out nukes/rockets if we had to. If you do the numbers, sure it comes out big, but 4 billion kg is not really that much - especially compared to the production capacity of 6 billion people over a couple of days. We could produce the required energy to move it by collectively winding handles let alone manufacturing nukes.
Besides that impending death is an excellent motivator.
If the projectiles are relativistic, then warning could only be a few days or even a few hours ahead of time. Even relativistic impactors are unnecessary. Low albedo impactors coming in from angles far off the ecliptic would be exceedingly hard to spot.
Of course aliens could do that, but would they? The evidence so far says that humans in possession of a superweapon, at least, don't annihilate one another simply because of the possible threat of superweapon acquisition posed by the other - otherwise we would have annihilated the Russians and/or Chinese in the 40s and early 50s.
At any rate one would think that aliens would at least understand the concept of mutually assured destruction and realize that we would not destroy them if they were capable of retaliating in kind...
The premise of _The Killing Star_ is that relativistic weapons wielded by star faring civilizations can make first strike the only viable opition. If you can't see them coming, and if they can wipe you out with the first strike, then there is no Mutual Assured Destruction. There's only a first mover advantage of apocalyptic proportions.
No warning + no survivors = no retaliation = no MAD.
Also, the historical evidence is that we've been dangerously close to nuclear war on too many occasions for comfort.
Contrarily, I think that any civilization capable of reaching Earth must also exhibit the most humane (aliene?) characteristics such as love for justice and respect for other lives. I'd imagine with their great power, every individual in their planet can, with the flick of a finger, wipe out a large portion of their own race if not entirely. They must have learned to coexist or face self destruction. It's a prerequisite to freely roam the universe.
What about killing for their own survival, after all respect for the lives of one's own race doesn't translate to respect for lives of others. This may be true, but with their intelligence I'd think they're smart and reasonable enough to explore other possibilities. I don't think aliens in soon-to-be-out-of-resources ships desperately flying around the universe for energy is a scenario advanced intelligent life forms planned for. It's more likely that they accept a peaceful conclusion to their existence.
Of course, it's very possible that we're all wrong since we're projecting our own primitive reasoning on species that are a lot more evolved.
You don't have to be nice to others to survive as a species, you just have to avoid genociding your own. Humans have managed not to nuke each other yet but we are mostly a predatory species and, with a few exceptions, have very little respect for non-human life. This theoretical advanced civilization might just see us as pests and accord us the same level of justice that we do to cockroaches.
respect for intelligent life actually might be beneficial
(just a side note: my belief is that not only humans are cognitive beings, so my respect applies to all life, but that's a bit offtopic, altough might be present in aliens as well)
Or perhaps a million years ago in their history, a sense of individualism completely disappeared as they joined into a single superintelligent creature. Totally xenophobic and without tolerance for anything that might threaten it :)
Why would you think that? I just can't see any basis for such an argument beside massively wishful guesswork...
"Of course, it's very possible that we're all wrong since we're projecting our own primitive reasoning on species that are a lot more evolved."
I completely agree with this though - you can't reasonably guess the consequences of future intelligence until you actually have it. Also, who said intelligence is on a single scale? There could be multiple types of advanced intelligence, each with their own chain of development.
The projection thing has been fueled by all the literature that was produced during wars, that is the entire human history. What to say about books or TV shows created during the cold war?
War is idiotic. Bringing war through incommensurably immense voids is nonsense. The only reason we can't see it is that we're used to rationalize the sad fact that we are too primitive to stop it.
Considering the only example of life we've seen is all of these species that co-evolved on earth, I think it's a little too early to understand what "life" even means, no?
After all, it might be that there are many more variations of evolutionary paths than the inverse of the probability of one getting this far... and who knows what a different evolutionary path for an ecosystem looks like? There is no reason our imaginations could be even remotely suited for such a task.
This is a valid point, and I'd take it a step further. Not only are we not well suited to speculate on the nature of life "at large", we're even less suited to speculate about the nature of intelligent life (whatever that even means).
On the other hand, should we encounter sentient life, it certainly is not difficult to imagine hostility or callous indifference -- from either party. Particularly if said encounter is not on our terms.
And as profoundly exciting as the prospect of meeting alien life would be, I'd much rather it occur sometime after we've grown up a bit, ourselves.
So we should not speculate at all? That's a rather dull outlook.
I certainly agree that our dataset, re: "life as we know it", is horribly limited. Likely to the point of uselessness. But hypotheses are the foundation of any science, after all, and what little we do have to go on suggests that competition/predation, rather than cooperation/symbiosis, may be a more reasonable expectation.
But perhaps not. In which case, we'd be very lucky to encounter such an enlightened species.
Actually, after you've been struck by lightning once, your chance of getting struck by lightning again is the same as getting struck by lightning in the first place.
The idea of aliens conquering earth for sole purpose of collecting resources seems pretty ridiculous to me. Given the scale of planetary evolution, they are much more likely to be a million years more advanced than us than a couple hundred. There would be so many celestial bodies out there rich in resources for such a civilization to choose from, why wouldn't they just take one of the millions of bodies that doesn't have nuclear weapons on it?
The point wouldn't be to collect resources. It would be to ensure that those monkeys with nukes and star drives don't try to do something bad. They won't try to steal our water. They'll just try to wipe us out, probably with bombardment from distances far beyond orbit.
I wonder if he is going to talk about "singularity" life forms outside of earth. It seems to me that eventually, we're headed towards a giant computer based "consciousness." Therefore, the idea of aliens living on ships seems a bit odd, and more likely that the ships themselves will be aliens.
The idea of cities on other planets seems nice, and seems natural given where humanity is at now. I don't imagine it will be that way for civilizations that develop much more than our own.
There's zero evolutionary reason for aliens to behave altruistically towards us.
If the aliens are still living in cities and orbital structures, then they'll want to wipe out a star faring human race. Any species capable of star travel can also accelerate and target enough low albedo impactors (perhaps relativistic) to wipe out a planetary or even system-wide civilization. There would be no warning, so there would be no possible deterrent. The only logical way to avoid genocide would be to strike first.
If the aliens have uploaded their consciousnesses and have all become spacecraft themselves, then we would be safer when encountering them. Wiping out such a civilization would be too difficult, so there would be a deterrent factor working on their behalf. There would be no need for them to act first to avoid genocide, and there would be no options in our case.
The only potential caveat to "There's zero evolutionary reason for aliens to behave altruistically" I can think of is that it may be quite improbable that species make it to long distance, space travelling status without being friendly. Perhaps if they are mean they will wipe themselves out, and so the species that live long enough to journey far into space do so because they're friendly enough to live long enough.
The rest of what you say I think I agree with (though I have no idea what a low albedo impactor is).
the species that live long enough to journey far into space do so because they're friendly enough to live long enough.
Note that they only have to be friendly to themselves to survive to get into space. What if the mechanisms that ensure their peaceful cooperation just don't apply to naked apes? Just one example: we say that a smile is "universal" but that's just because it's wired into our species. An alien species would've been subject to an entirely different evolutionary context. A smile would be meaningless to them. We still don't know everything about how altruism works in our own species. I posit that we have not a clue about how it would work with aliens, or even if it would exist at all towards us.
(Another example: when was the last time you felt pity or forbearance in response to a reptilian submission signal?)
I have no idea what a low albedo impactor is
It's a kinetic projectile that doesn't reflect a lot of light.
"There's zero evolutionary reason for aliens to behave altruistically towards us."
But plenty of logistics and game theoretic ones.
Logistics: An expansive starfaring culture can garrison every rock in the galaxy within a few million years. The fact that they haven't means that either (1) no such cultures exist or will exist in our vulnerable window, in which case we are unconditionally safe, (2) the galaxy is already garrisoned and they are tolerant, in which case we are conditionally safe as long as we don't piss them off, or (3) we currently live in the special 0.1% of the galaxy's life when a hostile culture is expanding but has not reached us yet, in which case we survive mostly by random luck. The likelihood is that we are in scenario #1 or #2, but cannot know which.
Game theory: A group is deterred by internal risk analysis, not external threat. A clever expansionary culture will run the logistics analysis above and decide that hostility has a horrific risk of backfiring. (For a fictional example, see Greg Bear's Anvil of Stars.)
You leave out another possibility: that the more accurate game theoretic analysis indicates that pre-emptive strike has a good chance to succeed, with little chance of survival or detection by the target civilization. The best option is actually (4) never ever let on that you exist in the first place. I think this is infeasible given the psychological makeup of our species, but perhaps possible for another. In this case, the galaxy is garrisoned, but the aliens know we have some time before we are star faring, so they can take the time to knock us off in a way the least likely to be detected by another species.
I think that humanity still has trouble with accepting insignificance of its efforts. We cannot even grasp how advanced would be civilization that is 1000 years more advanced than ours and 1000 years is a blink of an eye in comparison to most likely time of offset between two neighboring civilization.
Hit earth for resources? If an alien civilization has capability of interstellar travel at galactic scales then it surely has the abilities to harvest necessary resources from uninhabited planets that are much more common in universe.
Alien civilization might be interested in life itself though. Life is a evolutionary solution of a very complex nonlinear problem. Designing proper life for given sets of conditions might be hard even for very advanced civilization so they might be interested in every instance of naturally existing solutions such as place where life evolved spontaneously.
We cannot know the motivation of aliens. However, we can know that they evolved. The process of evolution means that whatever their version of "genes" are were those that were most successful at replication.
Organisms composed of genes that were the most successful at replication are undoubtedly dangerous. However, in order for them to come up with technology, they must have developed some semblance of cooperation. It's unlikely for star travel to be developed and kept by only one long-lived individual (although possible)
The question is how far does their cooperation extend? Even in humans, we're only really good at cooperating with close relatives or mates, and the same is even more true for other animals.
So I think the point is valid.
Except that I'd definitely be willing to sacrifice the entire Earth for 10 minutes of interaction with an alien being :)
If it were up to me, you will not be on the first contact team! Not sure if this makes you better or worse than Gaius Baltar. He betrays humanity for nookie with someone who looks like Tricia Helfer.
A darker, more games-theoretic take on first contact.
quoth this link:
They won't come to get our resources or our knowledge or our women or even because they're just mean and want power over us. They'll come to destroy us to insure their survival, even if we're no apparent threat, because species death is just too much to risk, however remote the risk...
This only applies if they are still living in cities and orbital habitats. If a significant number of them have uploaded their consciousnesses into spacecraft, effectively becoming spacecraft, then they become exceedingly hard to wipe out. Then they will have no motivation to act preemptively.
> He suggests that aliens might simply raid Earth for its resources and then move on
Umm, if they can travel to earth and gather resources (at a cost less than the fuel, time, etc), why wouldn't they just raid an uninhabited planet? there are plenty, and they have resources too. this makes no sense.
Why would you go through the effort and uncertainty of hunting wildlife when you can just saunter down to the local grocery store and pick up prepared meat?
Why go to the store to buy bottled water when you can get clean fresh water from your tap at home?
We have enough of a challenge explaining human motivations, we can't know any potential alien motives. We don't have any context. So far science has taught us that reality consistently overturns our preconceive notions and it indeed far stranger than what we've anticipated. Just one example: We knew that light was propagated by the luminiferous aether until the Michelson Morley experiment blew that assumption out of the water.
Given the highly logical minds required to develop technology that could let them traverse the stars, assuming them to make a decent cost-benefit analysis is not unreasonable. If they raided Earth for resources, it would either be because we had something rare, or because they're malicious sons of bitches.
You make it sound as if there'd be no reason at all. There's always a reason, and it's generally comprehensible even to us. We can understand the motivations or behaviors of non-human life just fine so far, and we have examples of our continued understanding all around, ranging from simple single-celled life forms to complex plants, animals, etc. . Why should life be incomprehensibly different "out there"? It can be modeled, motivations examined. Basic evolution will most likely still apply. They want to survive, and this is a basic logical tenet that weaves the fabric of the psychology of any lifeform.
We can argue back and forth as to how aliens could think. You are assuming that logic follows the way humans think.
I'm not saying there is no reason, I'm saying that we have a single data point for intelligent life, here, on Earth.
Why should life be the same as on Earth? Because that is what makes sense to us given our current knowledge of the universe, our biases? I would like to think that aliens, whether or not they inhabit the same rough space and time as we do, would follow the same logic, the same science of right, which we humans have, but I would still be making the assumption based on life on one single planet, where only one tool making species someday maybe capable of interstellar travel. For that matter, practical interstellar travel may not even be possible except for generation ships.
There is no "human logic". Logic is logic. It encompasses thoughts both natural and foreign. Who, for example, really finds the Banach-Tarski paradox intuitive? And yet it's logical. In fact, it follows from somewhat intuitive logical rules. But, hell, we can throw those out, too. We can accept a logic that, for example, rejects the entire concept of implication and the principle of explosion. A logic which can have two contradictory things both be true, without causing the system itself to fail. The limits of logic have nothing to do with what is natural to humans.
Axioms are not things that exist just floating in space, but neither are they things that only exist to a human mind. Logical implications can be defined, and inferred, in a useful way that applies to systems that don't understand logic at all! Even if aliens thought in a way entirely, well, "alien" to us, they could still be described by logic, even if they themselves found the idea patently ridiculous, because even their formation followed physical laws, and their development followed biological laws.
Perhaps not laws that we are familiar with. Perhaps the life we hypothetically encounter is just one monolithic life-form that developed in solitude on a planet, and self-developed. Normal rules of evolution do not apply when there is only one creature. But, that's not to say that there were no rules. For to survive, it still must have done something right. And in a universe with some known laws, what is right to survive can be surmised quickly: it obviously didn't jump into its sun right away and perish. Suicide cannot coexist with life. So already we can figure out one thing: this singular life-form that "evolved" in such a strange manner does not commit suicide.
Other aspects might be harder to find. Is it peaceful? There's no way of knowing. Whether it's peaceful or not has nothing to do with whether it survived and developed to get here, because it developed entirely in solitude. But, is it very sociable? Almost certainly not. A thing that has never before seen other life won't even comprehend what it is to be social. It's just like us examining quantum physics. What on earth is going on? We can't understand things totally outside of our experience except by analogy and coincidence, and here there is almost definitely no analogy, only a freak coincidence of mental structure.
So you see, we can reason about things logically, even if they are alien. We've reasoned about quantum mechanics, despite never seeing it, and despite never even understanding it. We've reasoned about single-celled organisms, things that are incapable of even thinking. We have reasoned about automata and machines, about chemical and nuclear reactions on a scale so far beyond the realm of our comprehension that we can never hope to appreciate it on anything more than a dumb, primitive level. We do it even if we don't understand, because the tools of logic are universal. Not by virtue of some belief or god, but simply because things have patterns. Even alien things.
> Why would you go through the effort and uncertainty of unting wildlife when you can just saunter down to the local grocery store and pick up prepared meat?
Because, to use your analogy, that would be like the aliens living in New York, but doing all their shopping at a local grocery store located in London.
The distances to these far of galaxies are measured in the hundreds of millions of light years, if not further.
all the local group galaxies are within 10 million light years of Earth.
For that matter, some of the "life is everywhere" theories assume many space-faring civilizations within our own Milky Way galaxy, which is only(!) about 100,000 light years across.
In reference to several commentators WRT to the energy you need to command to get to another star system, as I recall Eric Drexler in Engines of Creation posited this approach:
Use lasers pumped by your sun to accelerate a solar sail probe to a good fraction of c. Once that's done, the probe reassembles itself into a linear accelerator. As it flashes through the target system, the accelerator deaccelerates tiny probes, which make their way to planets. Those probes of course have nanotech which they use to assemble ... stuff (maybe even copies of the aliens).
Any one of a number of science fiction stories continue the plot from there.
Note that this approach will result in a signature the target system can see, as described in Niven and Pournelle's The Mote in God's Eye.
"You never open your mouth until you know what the shot is." (Glengarry, Glen Ross)
It is always better to eavesdrop on the other unknown civilization before they eavesdrop on you. It gives you the chance to make a decisive move: invade, cloak, whatever. Hawking is dead right.We should be expanding in a way that is as invisible as possible to the rest of the galaxy. When we do find the aliens, we should pursue a normal intelligence gathering approach, collecting lots of information about them while misrepresenting ourselves as being more primitive and harmless than we are. Self preservation dictates this sort of stuff. It could explain the Fermi Paradox.
I find these sorts of arguments rather short-sighted.
If there are aliens out there, they would have to have evolved technology at a rate within a few hundred years of our own on a scale measured in billions for this discussion to even be relevant. It seems to me that the odds of aliens existing and evolving at a rate so precisely aligned with our own are pretty slim, compared to the odds of aliens evolving somewhere at some time.
If the aliens are more than a few hundred years behind us technologically, it's not likely to matter all that much what they think of us. And if they are more than a few hundred years ahead and they really do turn up on some huge nomadic spaceship that has been travelling across open space for millenia, what exactly do Hawking et al think we're going to do if they are hostile and decide they want to take over our planet? They could squash our entire civilisation as easily as we would control aggressive garden pests, and with about as much concern.
What I find saddest is the assumption of hostility. If, as Hawking suggests, we look at the development of our own species, we find that where communities have formed and their members have collaborated for mutual benefit, they have typically done better in the long run than any aggressive group. You can take stuff and destroy things by force, but you advance by building new things, and sooner or later you usually advance to the point where taking the other things is no longer relevant anyway. In our case, we haven't cracked the secret to eternal life or worked out how to solve planetary overcrowding and resource shortages, but just about anything else is on the cards as technology improves. Why, then, would we assume that an alien race that has advanced sufficiently to allow serious space travel and has sufficient power to pose a threat to us if it wished would actually be hostile?
So broadcasting the 1936 olympics loud enough to be picked up within a few light years might not be such a good idea? And pumping out an aggregate radio signature approximately equal to that of a small star might not be such a good idea?
Thing is, with the size of the universe, our signals may only reach civilizations with sufficient technology to understand, millions of years from now. And a million light years is minuscule in itself.
I think we'll evolve towards general computational intelligence, improving our calculating substrate as we learn more about fundamental physics. Eventually, matter and 3 dimensional space and time are all just one very narrow view of reality. Transcending these things renders us invisible to those still bound to them. Likewise, intelligence that came before us followed the same path.
All this guff about peaceful aliens misses the point - I think this is more like Pascal's wager.
Consider the cases where we hide:
"If aliens exist and are very nasty, I'm sure glad I didn't broadcast our existence to them"
"If aliens exist and are super peaceful and awesome, well, nothing bad happened because we didn't broadcast our existence to them".
Consider the opposite cases:
"Aliens are nasty and we told them we existed - now we are all dead"
"Aliens are super awesome, we told them about us and they didn't wipe us out, possibly doing something good for us".
No matter how good the potential benefits from "nice aliens" you are a fool to stake the future of the entire human race on what is essentially a gamble when you don't have to.
Closed ecosystems seem to reach a stable equilibrium of peace and natural harmony, eg Mauritius's dodo, so we don't need to fear aliens (er, unless they come here.)
But earth itself is a closed ecosystem and it's not in harmony - for peace, it must also be open within.
I can picture in my mind a world without war, a world without hate. And I can picture us attacking that world, because they'd never expect it. - sadly, past tense
Evolution rewards the most vicious and aggressive species that is best at adapting to and use its environment. Since evolution is presumably also the process behind intelligent alien life I have a hard time buying the stable equilibrium of peace and natural harmony theory.
Just look at ourselves - wars in iraq, Afghanistan, Somalia, Palestina, etc. And these are peaceful times. As a species we are extremely vicious and aggressive and there's no reason to believe that evolutionary successful aliens would be any different.
I can agree somewhat with your first paragraph, but "ourselves" is rather nebulous. I'm not in Iraq, Afghanistan, etc, and if I were, I certainly wouldn't identify with the men who sent me there. There are 6.8 billion of us, which makes it kind of hard to lump us all together as "vicious and aggressive."
Evolution is neither. It does not have any such personality traits, and there are plenty of examples of symbiotic behavior in nature.
We just fill the gaps. If there's a niche to be filled, and an extraterrestrial species can fill it at our expense, then so be it.
Evolution is certainly aggressive, and rewards aggressive moves. It's all about being able to better use the resources at your disposal as a species to gain an advantage. There's no sense of right or wrong in this selection process - if you proliferate you live on, if you don't you become extinct. There are certainly examples of symbiotic behaviour, but only so long as both parties have an advantage of the relationship. There's no free lunch.
This also goes for infighting among our own species - one tribe continually tries to gain an advantage over others. Just look at global politics to see that this isn't about being fair only about expanding your own territory and power. If you look at what historically happens when a less civilised tribe meets a more civilised (and better armed) tribe it's pretty obvious. The Mayans, aboriginals, eskimos and native American indians have all been exterminated or marginalized in the most vicious ways.
"It's all about being able to better use the resources at your disposal as a species to gain an advantage."
Of course. I'd prefer "efficient" to "aggressive", though. True, the literal definition of aggressive does fit, but seems to imply intent (or even malice) in common usage, neither of which are possible attributes of evolution.
"Just look at global politics to see that this isn't about being fair only about expanding your own territory and power"
This returns to my point. I'm not a politician, and using the behavior of politicians or generals to predict my behavior is specious. Yes, we are a competitive species -- I made comments to this effect further down the page. I don't think we fundamentally disagree. I only object to the characterization of the "wars in iraq, Afghanistan, Somalia, Palestina, etc" as somehow indicative of the fundamental nature of life in the universe. As I and others have commented, we don't have much to go on in that arena.
Note that I was talking about closed ecosystems. How do you explain the specific example I gave of the dodo?
There are many other examples from similarly closed systems, such as New Zealand birds, before man (since we opened them).
I would argue that the world formerly comprised many isolated ecosystems, which have began to open over our recent history. Although the world has shrunk towards a global-village - becoming more open within - I would say most is still too isolated. It also probably takes a long time for even a fully open ecosystem to settle down, possibly on an evolutionary timescale of millions of years. But once a closed system happens to come to a stable state, it stays there (til disturbed.)
OTOH, maybe constant warfare is another point of stable equilibria?
Evolution is never at an equilibrium - it's constantly changing and experimenting through sexual recombination and mutation. So the premise doesn't hold IMHO. The dodo is an example of a species that was caught off guard in this evolutionary arms race, and was viciously exterminated by another species, namely us. Certainly there are species without natural enemies (swans, blue whales, man etc.) but they are the exception not the rule.
If evolution is constantly changing, how can a creature be caught off guard? The answer is that in a closed system, it is possible to reach a stable point that it is difficult to jump out of: in the search space of genotypes, there is a local maxima in the utility of the phenotype.
One thing I was wrong about was that the stable equilibria doesn't exist indefinitely; eventually a mutation might arise that does jump out. I was also assuming that a closed ecosystem was also closed to change in general. The latter seems more common; that equilibria is upset by an outside event that alters the utility of the phenotype - such as an open system closing, or some non-biological change in the environment (eg climate), and not by a change in the genotypes within the closed system.
It is possible that aliens are in one of these stable configurations at the time that we encounter them, which seems more likely in closed ecosystems. Closed ecosystems can be created by internal barriers being removed (which intelligent life, or at least we, seem to be doing). Of course, it's harder to eliminate change altogether (!), so that source of alteration in the utility function would remain. Yet, we certainly have motivation to eliminate environmental change that affects us adversely, so perhaps intelligent life is likely to be at equilibrium, in the long term.
If you disagree, I request that you indicate with which part. ;-)
This is very wrong to assume. What if they have accessed the technology to travel without producing it, therefore not having reached any kind of peace equilibrium you are suggesting required for their species to survive and progress?
Any if you are going to play with the words just use the extraterrestrial one.
I don't quite follow your second sentence, but I agree that their staying at home doesn't necessarily mean they're peaceful (we're not); I was just noting one way that they might be peaceful.
But if they are traveling around, our own history suggests they're (probably) not peaceful. Then again, we have travelers who are traders, who are migrating, who are explorers, who are tourists etc. To travel doesn't necessarily mean you're expansionist; it's just that whenever you think of conquers, they were travelers - of course. You can't stay at home and conquer.
There's an interesting idea that to be conquered doesn't necessarily mean that your civic organization and culture is conquered. If your government etc works well, conquerers have often adopted it (ie they are conquered), and the rulers rotate, coup d'état. Military superiority doesn't necessarily imply civic superiority.
BTW: Headlines with puns or allusions are usually deliberate.
Right now the burden of establishing Earth-alien communication pretty much lies on the aliens, so it doesn't matter what we do. Our conscious attempts in contacting other world are so feeble in their scope and reach that it hardly matters if we do them or not.
At the same time, the Earth is releasing enough signals (think lights and satellite TV) and artificial objects (satellites) to be noticed by anyone bothered looking.
Space faring civilization should be Stage 3 civilizations which has mastered the tech of harnessing stars for energy (dyson spheres) hence there is a good chance that they will be intelligent enough to know there are more cons to pros in eradicating us. I would think they will observe, study and do the best course of action. At best, they will act diplomaticly, at worst we will be enslaved.
I had expected something a little more profound than 50s science-fiction theories... There are so much more theories (i.e. non-biological life, etc.) that the view in this article seems awfully limited.
I can only conclude that Hawking has never seriously thought about it. There are NO galactic faring civilizations. If there were, they would be here now. I remember reading somewhere that it would take an expansionist civilization 10 million years to populate the galaxy. Given that the age of the galaxy is somewhere around 13 billion years, it is improbable that the first galactic civilization is on its way but hasnt reached here yet.
How about a nearby civilization, about our age? Charles Stross has done an analysis of the economics of star flight and came to the conclusion that interstellar travel makes no sense at all. http://www.antipope.org/charlie/blog-static/2007/06/the-high... It may not be possible at all.
I think that the idea that another civilization would want us for out resources is silly, for economics alone. If they wanted to leave their star because it was about to collapse into a white dwarf, there are better places to go. Any nearby M class star would have the resources to rebuild a civilization. The comet an asteroid belts can supply the materials without the problems of a deep gravity well like the earth.
It's not very likely they would like to touch the Earth when there is so much water, carbon and miscellaneous metals on the Oort cloud for the cost of towing them into your processing facility. It also spares them the need to enter lower orbits around the Sun. We don't see it as a gravity well because we are at its bottom, but if a deep spacer could choose, he would probably not enter it.