Active SETI.

[Sky_walker]

Wwe are anthropomorphising heavily here. Aliens will not be like us. They will not be driven by human-like ambitions or fears, because they will not be humans.

What we care about is a binary operation:

Either they're danger to our civilization or not.

If they are - Active SETI is a horrible idea. If they are not - it's a brilliant idea.

Any civilization capable of space flight would need to have an in-depth knowledge of mathematics, and that's enough to judge behaviour of another civilization when encounter would happen. Mathematical projection look very bad for humans:

What you call "anthropomorphising" is simply an attempt of applying universal science to the prediction of future for another civilization. Something that they'd very likely do at least at the very beginning.

What if there is a very advanced civilisation in some 20 light years away from the Sun - but their culture evolved differently to ours? Instead of building technological society their advancement was concentrated on philosophy, art and "soft" sciences?

Civilizations like that are beyond scope of this discussion. They in vast majority won't be inclined to leave their planet. Unless they happen to have animals capable of FTL travel - they'd require tons of "hard" science in order to reach Earth - science that's easiest to learn by expansionary species.

Or there might be highly advanced technological civilisation - but they simply do not believe that any other intelligent species exist. As such they do not try to communicate with anyone, nor listen for extraplanetary signals.

Any civilisation advanced enough to achieve space flight would have capacity to calculate (at least very approximate) probability of life in the galaxy, and by that: they'd at least look for a signal.

Separate matter is if they'd look for what we're sending - they equally well might come up with a conclusion that lasers would be most efficient way, so instead of looking for radio frequencies - they'd look for light, something in style of irregular flashing, even more so as this can also lead to discoveries of planets circling around the stars.

IMO, i don't think that any aliens would stand a chance at conquering earth. We are the masters of this world. We have thousands of years of experience in warfare on this planet. While the various SciFi movies are amusing they do not resemble reality. Aliens would be limited to the laws of physics like we are. And the fight would be on our territory which we know best. Also i highly doubt that if there is ET out there any of them will have the resources to start an invasion on a planet that is that far away. Even if they had it would be an requirement for them to have FTL technology (if it is even possible to have). I guess by the time an planet reaches that tech level, war would not matter anymore for them. In any way we don't have to fear anything. The worst but most unlikely case that could happen is that we get exterminated. I would call that just when i recall what humankind already destroyed on this planet. The more probable scenario would be that ET gets his butt kicked. I for my part am prepared to squash some bugs in the case they come to play wargames.

Problem with that is quite obvious: You seem to assume aliens would seek out to kill every single human out there. What for? It's enough they'd kill over 75%. And that can be achieved by surprise orbital attack aiming at sources of light visible from the orbit. After that we are not a threat in a long term any more for a civilization with technical capability of crossing distances between stars in a reasonable amount of time.

We with our nukes and missiles wouldn't be much more of a danger for them than tigers or lions are for us.

Edited July 10, 2014 by Sky_walker

[Kinglet]

First physical contact:

*alien vessel door opens and alien walks out*

Alien: "We greet the humans of earth. We have no intent to h-

*Idiot with weapons runs towards the alien*

"EAT SHOTGUN YOU EVIL ALIEN!"

*alien gets murdered*

And then earth is pretty much doomed.

Problem with that is quite obvious: You seem to assume aliens would seek out to kill every single human out there. What for? It's enough they'd kill over 75%. And that can be achieved by surprise orbital attack aiming at sources of light visible from the orbit. After that we are not a threat in a long term any more for a civilization with technical capability of crossing distances between stars in a reasonable amount of time.

We with our nukes and missiles wouldn't be much more of a danger for them than tigers or lions are for us.

This is what the aliens will probably do, as humans lack ANY form of effective military orbital defenses.

Edited July 10, 2014 by Kinglet

[Kinglet]

Delete this post.

[Sky_walker]

This is what the aliens will probably do, as humans lack ANY form of effective military orbital defenses.

Assuming they would like to wipe us out completely and don't care about re-using the planet later on.... or that they're rad-proof themselves... or that nuking is necessary for them to begin terraforming... *eyerolls*

[Monkeh]

I'd like us to just listen. Granted the chances of alerting a hostile alien race of our presence is quite unlikely, there still is a chance.

Let us assume there is an intelligent and technologically advanced race out there waiting for us to find, within some kind of semi-reasonable travel distance with some super tech that we haven't imagined yet. Now imagine their evolution, it's no coincidence that all of the smartest animals on our planet are carnivores, predators, hunters. You need to be clever to catch another life form to eat just as prey animals need an escape mechanism, be that speed, jumping, flying, disguise, 360 degree vision etc.

If the intelligent race we throw some radio waves at are predators and hunters then we might just become their latest hunt, (would be fun to watch all the fox hunters getting chased down and ripped apart I suppose), and that wouldn't end well. That or they wouldn't like the competiton and we'd find ourselves getting bombarded by Oort cloud comets for a millennia or two, maybe big rocks from the asteroid belt instead, that would be faster of course, either way I feel finding aliens won't be all sweetness and light and mutual benefit anyway, we can dream, but would you gamble the fate of your entire species on it?

[Seret]

Mathematical projection look very bad for humans:

https://upload.wikimedia.org/wikipedia/commons/thumb/b/b7/Population_curve.svg/350px-Population_curve.svg.png

[Kinglet]

Assuming they would like to wipe us out completely and don't care about re-using the planet later on.... or that they're rad-proof themselves... or that nuking is necessary for them to begin terraforming... *eyerolls*

[Nibb31]

It actually doesn't look so terrifying if you include the estimates for growth over the next few decades. It's likely most of the worst is over:

https://upload.wikimedia.org/wikipedia/commons/thumb/1/11/World_population_%28UN%29.svg/271px-World_population_%28UN%29.svg.png

[Seret]

Log scale is logarithmic. Flatten the scale and those curves are still exponential except for Europe.

The point is that is shows the rate of increase is slowing. Exponential growth would be a straight line on a log scale, but those lines are flattening out. The middle-of-the-road prediction does have us topping out at about 10-11 billion around the end of the century. The lowball estimate could be a decline to 6 billion. The high estimate is frankly a bit scary, as it shows continued growth at the current rate and we'd be looking at nearly 30 billion. In which case we would probably be as stuffed as Sky_walker was suggesting. I'm not convinced a population crash would have to be an extinction event though, populations cycle in nature all the time.

[Scotius]

*sigh* Come on guys...

"We came to be dominant species on Earth by being murderous b........ Therefore all other intelligent species should be similiar to us to achieve dominance on their respective planets." Not. True.

If that would be the case, amazonian and new guinean jungle would be carpet bombed every time someone discovers a tribe that did not had any contact with XXI century civilisation. Which is not happening. On the contrary - scientists and local governments go out of their way to protect such people as much as possible. Genocides happened in the past, sure - but now apparently we know better.

[Seret]

"We came to be dominant species on Earth by being murderous b........ Therefore all other intelligent species should be similiar to us to achieve dominance on their respective planets." Not. True.

Taking only Earth as our example it does seem a fair assumption that intelligence is associated more with predators than with prey species. Hunting rewards big brains, but herbivores don't need a lot of mental agility to eat. Plants are pretty easy to outmanoeuvre.

However, on the flipside of that is the fact that we're efficient predators because we're social. Physically a human is pretty woeful compared to a Bengal tiget or a great white shark, but our ability to cooperate put us on top. It's quite possible that a high-tech alien species would (like us) be capable of both violence

and cooperation.

[magnemoe]

The point is that is shows the rate of increase is slowing. Exponential growth would be a straight line on a log scale, but those lines are flattening out. The middle-of-the-road prediction does have us topping out at about 10-11 billion around the end of the century. The lowball estimate could be a decline to 6 billion. The high estimate is frankly a bit scary, as it shows continued growth at the current rate and we'd be looking at nearly 30 billion. In which case we would probably be as stuffed as Sky_walker was suggesting. I'm not convinced a population crash would have to be an extinction event though, populations cycle in nature all the time.

This change will come faster than we think, most of the population growth now is because the large population is having kids while their grandparents are still alive.

We all know birthrate in Europe and China is below replacement. However the same is true in most of Latin America and the Arab world the last 10 years.

Think most UN estimates assumes 9 billions as a peak.

[Seret]

Think most UN estimates assumes 9 billions as a peak.

That's the 2050 estimate IIRC.

[Idobox]

*sigh* Come on guys...

"We came to be dominant species on Earth by being murderous b........ Therefore all other intelligent species should be similiar to us to achieve dominance on their respective planets." Not. True.

If that would be the case, amazonian and new guinean jungle would be carpet bombed every time someone discovers a tribe that did not had any contact with XXI century civilisation. Which is not happening. On the contrary - scientists and local governments go out of their way to protect such people as much as possible. Genocides happened in the past, sure - but now apparently we know better.

Well, it's true as long as the underground doesn't contain anything expensive. If there is gold, oil or copper, the forest disappears in a blink of an eye, and the locals are turned into beggars.

And even without talking genocide, we are permanently trying to impose our civilization on others. A good example is the fight between Western powers/secularists and djihadists, the foreign aid given in exchange of policy changes, embargo on Cuba, Iran and North Korea...

We Westerners are used to see it as trying to improve the world, but it can easily be seen as an aggression. Heck, I'm from Europe, and I consider the USA to be very aggressive in this matter, trying to impose not only their culture, but also their economic structure and idea of politics on the rest of us, although our differences are tiny. For the south east Asian fisher or the Amazonian hunter/gatherer, this must look like total war, it surely does for a lot of people in Muslim countries.

[K^2]

Active SETI: "We are here, we are not very technologically advanced, and we are very gullible!"

Doesn't sound like a good idea, no.

[G'th]

I really cannot believe how many cynics are here.

I mean, its one thing to be concerned about possible hostile species, as that's something we'll inevitably have to deal with when we start discovering intelligent extraterrestrial life, but its another entirely to just presume that just because Earth isn't a utopia that every other species in the galaxy will be even worse. There's literally no basis for that at all except irrational fear.

And regardless, if a species has the capability to cross the void and not only invade but conquer a planet and integrate it into a vast, possibly galactic empire, that species will also likely have very little need for natural resources, whether its because they can use what they have far more efficiently or because they're synthetics are superior. So that's one reason to conquer us that goes completely out the window.

If such a species finds us, they'll also likely ask us to join their empire before they decide that invasion is necessary. Subjugation by force is the worse thing an empire can do, regardless of whether its technologically superior or not, because eventually someone you subjugated will rise up against you, or become such a drain that maintaining a presence there would hurt the empire as a whole. And it wouldn't be stopped by technological superiority either, because an empire like that would inevitably have their own technology within arms reach of the subjugated, and that tech would be the first target. And sure you can say "oh well they'll just supernuke us from orbit blah blah" but what benefit would that be to them? No empire conquers territory just to have territory. Destroying a part of their territory would be the last thing they'd want to do.

[The Carrot King]

At this moment in time I think it would be unwise for humans to try and contact aliens. I agree with an earlier comment by THE SILENT MAJORITY, we should spread ourselves before we initiate contact. Even it was a peaceful alien specices to meet us, who is to say that they dont carry diseases that they dont even know of, or maybe theyr'e ships emit gas that is poisonous to the planet. There could be a number of things that go wrong and destroy the planet. Why would we take the risk before having a fall back. If they were advanced enough to find us and violent a back up plan might be a moot point, but why chance it?

[PakledHostage]

Active SETI: "We are here, we are not very technologically advanced, and we are very gullible!"

But it worked for the Pakleds... Maybe that should be our message to the stars? "It is broken..."

[Scotius]

You all are forgetting one fact: There is no stealth in space We can avoid broadcasting our presence via electromagnetic emissions (probably). But any carbon-based, oxygen breathing species only slightly more advanced than us will inevitably notice Earth. Next generation of our space telescopes is supposed to be good enough to examine atmospheres of extrasolar planets. If we ever find Earth-like planet orbiting a stable star, with huge amounts of oxygen and methane in its air, it will instantly become most interesting obiect for our scientists. And quite probably prime target for future exploration. Any possible civilisation hiding there will be discovered sooner or later.

[Duxwing]

Saving life on a planet.

Assuming that war that follows will be only targeted at humans with little to no collateral damage to the environment.

I speculate that any civilization that can and wants to save an alien planet's biosphere would also have the compassionate foresight to use education, evacuation, or regulation instead of genocide.

Life in the void universe is very precious thing, and humans prove over and over again not to give a s*** about it. Viewed objectively: we're basically a vermin that slowly consumes a planet. Killing off good 95% of human race would be highly advised from a perspective of alien spices. This would ensure long-term survival for a natural environment, while at the same time assure that there's enough humans to keep genetically healthy population.

Your description of human attitudes toward biota is too simple--and certainly too dark. We have effected such goods as the nigh-universal outlaw of murder, great difficulty of inciting us to homicide, enormous national parks, and mighty environmental protections throughout the developed world; whereas our bads have largely resulted from fear, ignorance, and desperation largely relegated to the barbarous badlands and dark of ages past. For example, when did important diaries last read, "All across Europe, the lights are going out."? 1914--a century ago.

You think so? Let's take a look at a very distant history. Once upon a time we did encounter another intelligent spices here on our planet - Neandertals and lead to their extinction...

"Post-hoc, ergo propter hoc" non argumentum est: Neandertals also relied on ambush hunting, which was extraordinarily difficult in the then-thinning forests of Europe. And even if our ancestors somehow exterminated the Neandertals, our ancestors were savages and therefore could not represent us.

...but ok, let's take a look little bit closer: North and South America during Colonial era, how we basically killed vast majority of the population on two continents and now hold survivals in Indian Reservations.

Or would you want to get even closer than that? Superstitions and racism lead to one of the greatest disasters in 20th century: Holocaust.

"we" had nothing to do with smallpox's unfortunately ravaging the land, and "we" had believed the inhabitants sub-human because of religious indoctrination now long-gone. I invoke Godwin's law!

And that's what we've done to our own spices. If any alien spices would ever found out about that - they'd be very inclined to wipe us out just for their own safety (as over time of co-existence we'd learn more about them eventually reaching a point where we'd become capable of inflicting significant causalities).

We've also produced at least one individual recognizing that such deeds as conquest and crusade are horrors not to be repeated: how many more like you exist? Any alien species also would learn that almost everyone involved in those fiascos, snafus, and shenanighans is dead and that the rest of us can't repeat them or can and know not to. By saying aliens would exterminate us, you seem to characterize them as genocidal and paranoid... just like you characterize us. Combining the set of all aliens and the set of all humans yields the set of all sentients, which you therefore must believe almost-unspeakably evil: why?

It's not intelligence. It's fear. An invention of Mutually Assured Destruction is the only reason why we're still talking here now.

MAD was necessary but not sufficient for our talking here: the Russian people eventually dismantled the USSR because they hated living in the world's largest open-air prison. They now enjoy profitable relationships with both West and East despite living under a villainous despot.

--

I believe that all reasonable efforts toward active and passive SETI should proceed and that we should greet whatever aliens we meet with diplomatic warmth, scientific curiosity, and entrepreneurial charm. The sensing technology needed to bring such large masses as warfare would necessitate to even nearby planets is so advanced that they would eventually find us whatever, and the growing benevolence this thread evinces when compared to similar discussions a century ago further evinces that life likely tends to kindness.

And besides, guys, what's life without a little danger?

-Duxwing

[rtxoff]

You really should keep politics out of this forum....

[sal_vager]

You really should keep politics out of this forum....

I second this, there's little to be gained by starting an east v west discussion.

[magnemoe]

You all are forgetting one fact: There is no stealth in space We can avoid broadcasting our presence via electromagnetic emissions (probably). But any carbon-based, oxygen breathing species only slightly more advanced than us will inevitably notice Earth. Next generation of our space telescopes is supposed to be good enough to examine atmospheres of extrasolar planets. If we ever find Earth-like planet orbiting a stable star, with huge amounts of oxygen and methane in its air, it will instantly become most interesting obiect for our scientists. And quite probably prime target for future exploration. Any possible civilisation hiding there will be discovered sooner or later.

yes, this is an important point and they will send their colony ships to the suitable planets with oxygen.

Detection range will be hundreds of light years, better with more advanced telescopes.

That is planets without signs of intelligent life.

The Rawee has long known about Earth they even did an probe flyby some thousand years ago, an later probe who was designed to orbit and send down landers failed.

however 200 lightyear away its too far to travel and they had enough colonies enough.

However 15.000 year later they had come closer and an new colony is only 50 light year away, they decided to reuse the mothballed colony ship in orbit mostly as many really hated the ecology on Nvan, firebreathing mosquitoes and carnivorous trees get annoying.

They started the trip in 1752 hibernating most of the time. Yes the radio signals they received during the braking burn was a surprise

Luckily all ended well, planet is nice and the local is amusing, they was very happy for our gift and most was willing to honor our queen. Yes it was some fighting then we had to suppress some revolting local traditions mostly pant, cheese and religion. Yes you have probably seen the fall on your tail laughing action shots of this.

----

yes it would be insanely fun making a first contact movie from the other side point of view.

[AndrewBCrisp]

If we do not learn from history, we are doomed to repeat it. Looking back over human history you'll see that the first contact between a primitive society and a technologically superior one, at best ends with the total destruction of the primitives' culture.

More to the point, technologically superior cultures destroy technologically primitive cultures if the following things happen:

1) The technologically superior culture (which we will refer to as Culture A henceforth) goes out and finds the technologically primitive culture (which we will refer to as Culture first.

2) Culture A wants something from Culture B or from the land on which Culture B lives which Culture A, for some reason, cannot get at home.

3) Culture A is disdainful of other cultures and doesn't mind mocking, altering, or even wiping out Culture B, and

4) Culture B is sufficiently rigid that it cannot reliably absorb shocks to its system.

So let's look at these items in order, as applied to Active SETI. Keep in mind that we humans will be playing the role of Culture B.

1) Culture A comes to Sol and finds us first. This implies that we aren't looking for other cultures - actively or passively. We stay at home and keep quiet for fear of attracting strangers. This policy of isolation puts the initiative in contact firmly in the hands/claws/tentacles/whatevers of Culture A, leaving us entirely at their whims. This can also occur if Culture A was to show up in orbit tomorrow, while we're still debating this issue.

2) Culture A wants something from us or our world that they can't get at home. This is a point I find very hard to accept, given that, as we learn more and more about planets outside our solar system, it is clear that most raw materials that exist in our solar system also exist in others. Anything they need to mine, farm, harvest, or manufacture, they can do so at home. If they have so depleted themselves that they need to mine other systems for resources, they will have likely depleted themselves to the point where they cannot travel to meet us, much less exploit us. We could, I suppose, imagine resources or things Culture A may desire from us, but that is speculation on top of speculation, and gets us nowhere.

3) Culture A is disdainful of other cultures and doesn't mind mocking, altering, or even wiping us out. This is the one point we can never know until contact has occurred. We can speculate all we want about how cruel or kind an alien culture may be, but until contact is initiated, it will remain speculation. I suspect even the aliens of Culture A may not know how they will deal with other cultures until they initiate contact.

4) Culture B - us - is sufficiently rigid that it cannot reliably absorb shocks to its system. This is the one item we can control, and that's by maintaining efforts to explore the universe and search for other cultures, both passively and actively. If we give up that search and turn inward, I predict we will, as a species, become less receptive to the concept of contact, and less resilient to the changes that will necessarily follow. Thus, when contact finally occurs, it will be more likely to break us - even if Culture A acts very carefully not to do so.

Conversely, an Active SETI policy can do the following things:

1) It puts the initiative of contact in our hands. Rather than wait for the hypothetical Culture A to find us, we start the conversation, and put Culture A in the position of having to decide if and how to reply.

2) It puts the concept of contact foremost in our minds, and a priority that must be tended to in our agendas. After all, if a suitably powerful beacon is built, sooner or later we will get a reply, either by radio or by ship. It would only be responsible of us to make sure we are ready for that eventuality.

3) It tells Culture A that we're serious about - and ready for - contact. Referring to the "Smart SETI" article I mentioned in my last post, the Benfords figured that a beacon capable of reaching out to 600 light years would probably need a cost of 4 billion dollars to run (Figure 1, page 36), and that is the minimum cost. That's about the cost of an aircraft carrier - or 1/4 of NASA's current budget, IIRC. Beacons detectable across greater distances will cost more. While Culture A will not be able to know our budget constraints, I expect they will be able to do the math on the resources needed to build a beacon, and realize how much we have committed to the effort. The more distant Culture A is from us, the longer the concept of contact will have been at work in our minds, and the greater the chance that we will have prepared for contingencies. Culture A will likely realize this once our beacon is detected, the distance (and hence time since the beacon was first activated) it lies from them, and so will know that, if they choose to initiate contact, they will have to tread carefully, lest they mess things up.

Of course, we do face risk if we send a beacon, but I submit the risk is greater if we stay silent - if they contact us, we will be reacting, not acting. And those who react always react at a disadvantage.

[The Jedi Master]

Yeah, I want my taxpayer dollars to be spent on something that won't amount to anything. Come on, even if we do find something, there isn't really much we can do about it.They'll be too far away for us to send a message back in a timely manner, so we can't even be pen pals.