Brainstorming Clever Ways To Detect Alien Civilizations 343
Phoghat writes "In what is starting to become a familiar theme, researchers have speculated on what types of observational data from distant planetary systems might indicate the presence of an alien civilization. Potential indicators of the presence of an alien civilization might include: atmospheric pollutants, like chlorofluorocarbons – which, unlike methane or molecular oxygen, are clearly manufactured rather than just biogenically produced; propulsion signatures – like how the Vulcans detected humanity in Star Trek: First Contact; evidence of stellar engineering – where a star's lifetime is artificially extended to maintain the habitable zone of its planetary system; or debris created from asteroid mining."
Modulated neutrino beams (Score:2)
Either in amplitude or PCM. Neutrinos interact with matter even less than Electromagnetic waves.
They are a bitch to generate (take an awfull LOT of energy), but that is the problem of the alien civilization trying to comunicate, not ours, at least for the time being.
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Either in amplitude or PCM. Neutrinos interact with matter even less than Electromagnetic waves.
Exactly - so why would you want to use them to communicate?
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Look for randomness.
I would guess if you find a source (other than Earthly) of randomness, at any energy level, it's probably produced by something intelligent.
It kinda pisses me off that every time I read or see something about SETI it's about looking for patterns. They should be looking for randomness.
Seriously? How much of that do we emit, other than your post...
clearly manufactured? (Score:4, Interesting)
Potential indicators of the presence of an alien civilization might include: atmospheric pollutants, like chlorofluorocarbons â" which, unlike methane or molecular oxygen, are clearly manufactured rather than just biogenically produced
Clearly? Maybe here on earth. Who knows what natural processes exist elsewhere.
Re:clearly manufactured? (Score:4, Insightful)
If we make unmanned probes and send them out, and one of our probes turns up CFCs in an atmosphere like our own, and we go there and find no life, then you'll have the right to say "I told you so."
Re:clearly manufactured? (Score:4, Informative)
The actual suggestion, as originally proposed by James Lovelock and expanded-upon by others, is that you look for the following:
a) Dynamic equilibriums involving chemicals that are unstable in each other's presence and/or in the presence of the radiation from their sun
Unless the chemicals are replenished, such a system MUST reduce to a stable equilibrium, although this is insufficient to say HOW they are replenished.
b) Evidence that one or more of the chemicals cannot arise naturally (ie: there ISN'T a geological process, even an unknown one, that could ever create the compound)
Not all chemicals have a natural proginator. Doesn't matter how alien the world is, doesn't matter how strange or exotic, not everything can happen naturally. The reliance on a mysterous get-out-of-jail-free "unknown" simply doesn't cut it for some stuff. Chemistry is remarkably simple and the rules of what chemical reactions can and cannot happen are very well known. Those rules are as true in any solar system in Andromeda or on any planet that has no sun at all as they are here.
c) Evidence that the compounds resulting from the natural reaction of the compounds observed in the atmosphere are BELOW the levels that can possibly occur as a result of the reactions that must be taking place
We can observe every damn element in an atmosphere along with exactly what compounds those elements combine to form, their ratios and their temperatures. There are no hidden variables within the atmosphere itself. If the chemicals that should be there aren't, then the chemicals are being removed by a variable that is NOT a part of the atmosphere.
d) As environmental conditons change (such as distance from the sun, etc), the ratio of compounds in the atmosphere changes such as to oppose that environmental change
ie: There's one or more negative feedback loops - not just on the addition of compounds to the atmosphere but also on the removal. Geological processes don't work this way. This isn't through our limited knowledge. Volcanos don't select what gasses they spew according to the time of year. If the gravitational pull is enough, they may vary in frequency. What they cannot do is vary in composition.
In addition, the vast majority of chemical reactions have POSITIVE feedback loops, not negative ones. The only way to produce negative feedback loops in sufficient quantity to overwhelm the positive feedback loops is to have a living component.
Meet these four conditions and life is guaranteed present. It may be present at some level when not all four are met (the statement isn't reversible), but it can never be absent when all are true.
There is NO extension to these rules which will allow you to determine the presence of intelligent life.
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Who says life has to be based on our chemistry?
They may poop diamonds for all we know. Remember the Horta. [startrek.com]
Dammit Jim, I'm a Doctor, not a stone mason!
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The Tsar bomb (57 megatons) was about 2 x 10^17 joules. Suppose all of that energy was released as visible light at a wavelength of 0.5 microns; that's about 6 x 10^35 photons, which sounds like (and is) a lot. However, at one light year (assuming a uniform blast of radiation), that works out to 500 photons per square meter.
Now, that could be detected, if you were looking for it. At 4.4 light years (Alpha Centauri), that's 26 photons per square meter, which would be detectable with a big telescope (maybe).
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If we wanted to announce ourselves, we don't need a nuke. A radio beam would suffice. If we wanted more of a "flare", that could be seen by everyone, a powerful, repeating omnidirectional pulse in a specific wavelength would attract more attention than a nuke, if only because it leaves less room for doubt.
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Presupposing the energy from an atomic detonation is even detectable across interstellar distances, we'd still need to be extraordinarily lucky in terms of timing.
On Earth, the only above-ground nuclear detonations, ever, occurred in the twentieth century, specifically 1945-1980 or thereabouts. I'm not including underground tests, as they aren't as easy to spot from a distance (they're easy to detect here on earth via seismograph, but that doesn't apply to the discussion) . If something out there were loo
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That just raises different questions (Score:2)
The detection of an atomic bomb throws off a unique signature not found in nature.
True but the question we then have to ask is do we want to contact an alien civilization that is throwing atomic bombs around...and is there any point given that chance are they will not be around for much longer? Even then atomic bombs are not that powerful considering that the planet is sitting not that far from a thermonuclear furnace many orders of magnitude larger than the entire planet.
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Actually, that would make good scifi, at least of the soft-ish variety. Possibility: a story in which an observation station in the outer solar system picks up the atomic bomb blasts in '45 and alerts someone to come investigate, with a two-year lag in arrival explained by the alien spacecraft taking that long to get here (it'd have to be FTL, two light years is too close for anything else).
It even makes sense if the arriving scout ship aims for the American southwest and not Japan; they'd be going for the
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There are at least two sites on Earth known where natural deposits of uranium were pure enough to have undergone a thermonuclear process of the kind found in a nuclear reactor. Although improbable, it is certainly possible for an entirely natural nuclear bomb to arise. It is, agreed, exceedingly unlikely but all the processes required do exist in nature and therefore must combine somewhere, at some point in time, in just the right way.
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It isn't. The Hiroshima bomb was a uranium bomb. It didn't use plutonium at all.
In terms of geometry, what you'd need is a naturally-occuring uranium deposit that contained sufficiently few impurities that it had achieved a self-sustaining natural reaction, both on the ground and on the meteorite. We know the first one is possible because we've found such places. Since it can occur on the ground, it is reasonable to assume it can happen in space under suitable conditions. You also want the deposits on the p
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Yes, that's how the Cylons located the remaining Caprican settlers!
hehe.. nailed....
How can we communicate with them? (Score:2)
If we can't even see planets, how can SETI expect to receive a transmission from one?
I've asked some astronomy majors about this and received only blank stares. Do they teach this kind of thing in astronomy? What are the calculations?
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Interferometry [wikimedia.org] is the short answer. The long answer is, no, it wouldn't be insurmountable to pick up Casey Kasem 50ly away with a good array.
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Interferometry [wikimedia.org] is the short answer. The long answer is, no, it wouldn't be insurmountable to pick up Casey Kasem 50ly away with a good array.
I don't quite understand the long answer; can you give me the short answer, please?
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Do they teach this kind of thing in astronomy?
Perhaps, but it's in every SETI FAQ, so you don't need to go to College to figure it out.
Short version: radio SETI is looking for intentional radiators.
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The light from planets is omnidirectional, time-continuous and over a frequency-continuum. You can save energy by only submitting in one direction and for a short duration and at a specific frequency. That's why SETI is looking for pulses from exoplanets or crowded regions, and recorded at suitable (presumably universal) frequency windows like the waterhole [wikipedia.org].
Search Google or Youtube for Seth Shostak on some SETI talks -- he also mentions how you can transfer a signal in a science fair project.
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What I've also wondered is how big of an antenna would we need to detect a communication from a near star, say 50ly. And how much power would it take to send a message that far? If we can't even see planets, how can SETI expect to receive a transmission from one? I've asked some astronomy majors about this and received only blank stares. Do they teach this kind of thing in astronomy? What are the calculations?
It's a fair question. Fortunately, an intentional transmitter can be much brighter than the star or planet -- in a narrow bandwidth and pointing straight at you. (And stars aren't very bright at microwave frequencies.) There's no problem communicating to nearby space if you know each other's frequency and direction. You can concentrate megawatts of power into
Interferometry (increasing the spatial resolution of the receiving antenna) actually doesn't help you much, except to discriminate against the d
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Meant to say you can concentrate megawatts into less than 1 Hz of bandwidth and then multiply the power by using a very high gain antenna. The big problem in SETI is not knowing where to look or where to tune your receiver.
You probably know this already, but for the benefit of anyone following along: antenna gain does not produce extra power. The purpose of gain is (when transmitting) to send all input power in a desired direction, and (when receiving) reject incoming signals from undesired directions.
When receiving, you will also need an antenna with a very large effective area so as to capture as many photons as possible. That's why Aricebo is so large; and being a dish antenna, it is also very high gain.
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To calculate, simply use the inverse square law, then make use of this information kindly provided by Wikipedia concerning information theory and noisy channels. [wikipedia.org]
Together, this along with the target distance to the alien planet will give you the optimum broadcast power for an intelligable message to be sent. Bear in mind that the SNR needs to be sufficiently high to still discern the signal from cosmic background radiation. Choice of broadcast frequency would be helpful here, but sadly I cant link you to any
Polution (Score:2)
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Heed the wisdom of Zapp Brannigan:
With enemies you know where they stand but with neutrals? Who knows! It sickens me.
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I agree.
1. It is not un-reasable that an advanced civ would extend beyond the origin planet to look for resources.
2. Resource extraction is messy. Waste does need to be dealt with no matter the environment.
In space you want the waste away from you and with a low probability to collision. The best way is to dump it into gravity wells like gas giants and suns. This is going to give of spectrum of some sort. Consider it spectral pollution The more industrialized the civ the more of this spectrum pollution
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Why spend so much delta-v? Space is big. Just put the waste into an orbit which doesn't intersect with anything you care about, and you're done. Spending the energy to collide it with the local star is ridiculous.
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Actually, it'd have to be pretty dire waste to make sending it into space the best option, unless the civilization in question has ridiculously low launch costs or is already living and producing waste in space (both possible, mind you). I could see disposal of the worst kind of unreprocessable nuclear waste in this manner, but just about nothing else.
If you did have waste that was that bad, I doubt you'd want to keep it in orbit. Spending a little extra delta-v to boost it into the nearest gravity well (
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Umm, yes. But, how do you look for pollution? I.e. what is classed as "pollution" here on earth might be quite normal elsewhere.
or have developed Fusion (Score:2)
If they don't have that then you probably don't want to talk to them anyway because they: 1- are too primitive, have no tech- nothing to trade or steal. 2- are envioro-nazis
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Signature on subatomic particles (Score:2)
How about instead of just trying to detect other civilizations that exist along side us, also trying to detect ones that came long before in the previous Universe. If the Universe is cyclic and there was another universe before our "big bang", one thing we could do is see if the particles around us have some kind of signature to them that would be unexpected. It may not be possible right now for us to make such signatures, but perhaps a previous civilization built large devices close to the end of the previ
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Kudos, you sounds like a real pseudoscientist !
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I am a pseudoscientist, as in I'm not really a scientist. But they wanted imagination.
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We could just keep an eye out for this guy. [marvel.com]
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If the Universe is cyclic and there was another universe before our "big bang", one thing we could do is see if the particles around us have some kind of signature to them that would be unexpected.
A couple problems here.
1) What works in Star Trek: TNG cannot be relied upon to work in real life.
2) The idea of a cyclic "Big Bang" is not consistent with the current understanding of the universe. Thirty years ago people took that concept semi-seriously, or at least didn't have a concrete argument against it - but that was back when they thought the universe's expansion was gradually slowing down rather than accelerating.
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They should watch Star Trek et. al. more. (Score:2)
Or maybe they did just that too much already.
Half assed approaches (Score:2)
had our cultural biases been different, our technological approaches and means would be different too. see, for example we are just starting to use crystals/light as technology, actually in the very places of other technologies we used before. when all these technologies based on light/crystal interactions are advanced enough, they will definitely shape our culture and expectancies too. what if we had had
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Worse than that, human activity from space would have been detectable for how many years? 2000? 3000? Likely less.
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Less than 200. Possibly less than 100. Unless by "from space" you mean "from Earth orbit".
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Biologic activity would have been detectable for much longer, though. High concentrations of atmospheric O2 seems pretty suspicious in the presence of lots of things it would like to bond with better.
trek trivia (Score:2)
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If they are more advanced than we are, they will have little to learn from us, and instead, we will be seen as a competitor for resources, or a more direct threat, or likely to become one. So their best course of action would be to exterminate us.
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Like being a good host or source of protein?
I think we're flattering ourselves if we think that's what aliens would travel across the universe to suck on our delicious brain meats. In all likelihood, they would be after natural resources, of which the most abundant, and likely useful, materials on this planet would be carbon, silicon, and H2O.
They are easy to find (Score:2)
Dyson Spheres (Score:5, Interesting)
Dyson spheres (or swarms) would probably be the best way to detect an advanced civilization, especially a Kardashev Type II or Type III civilization.
In a Dyson sphere (or swarm) a civilization surrounds an entire star to capture most or all of its luminosity; severely cutting down on its optical luminosity but accentuating the IR luminosity. (The physics of a rigid sphere surrounding a star are pretty challenging, and some sort of swarm or cloud seems more likely, at least to our limited technological understanding.) So, to hunt for a Dyson sphere, you look for objects with an unusual excess of IR, and a lack of optical light. The IRAS IR satellite was used to search for Dyson spheres within ~ 1000 light years of the Earth [arxiv.org] (producing a handful of so-so candidates). Carrigan [arxiv.org] calls these sorts of searches "Interstellar Archaeology." They have one great advantage in that they don't require any cooperation from the other end (i.e., no beacons or other signals).
As it happens, I have recently speculated that "Object X [arxiv.org]" in M33 (the Triangulum Galaxy) could represent the signature of a Dyson sphere / swarm from 3 million light years away [americafree.tv]. If this (unlikely) possibility were to be true, it would represent the signature of a Kardashev Type III or near Type III civilization. Interstellar Archaeology is the only possible form of SETI across such vast distances.
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Re:Dyson Spheres (Score:4, Interesting)
The linked PDF you provided speculates that "object X" might be a self-obscured star, obscured by its own ejecta.
If we assume that this is indeed a dyson swarm, then the purpose might not be exclusively for collecting energy.
A category II or III civilization would be doing asto-architecture, and would need tremendous amounts of raw materials. Heavy atoms are only produced naturally in one kind of environment: in the hearts of stars. If this star is regularly expelling large quantities of cosmic dust, as the linked article postulates, then it would make an excellent "Factory". Energy would be in copious abundance, and the star itself would be churning out millions of tons of heavy atoms every minute. Even with a short (compared to other stars) lifespan, it would make an excellent factory site for other large astro-engineering projects.
It would be far more economical than mechanically processing already aggregated matter clumps (planets, asteroids, etc)-- especially with a dyson sphere/swarm infrastructure. The emitted gas and dust would be strongly ionized, and a simple network of magnetic traps could passively funnel the more desirable metal and halide ions from the lighter non-metals, with very minimal post processing. It would go a long way toward eliminating material scarcity issues that would otherwise plague a category II or III civilization.
Spectrographic analysis of the dust cloud to see if it has an uneven distribution of heavy and light elements would be quite revealing if this is the case-- Heavy ions would be in greater concentrations nearer the solar mass than away from it-- contrary to what you would expect if it was merely a gravitationally bound stellar dust cloud. (the latter would have a fairly uniform distribution of dust and gas)
Sadly, since it is in another galaxy such spectrographic studies are not very easy to do in sufficient resolutions to make such distinctions. It would need to transit some other more luminous celestial object in order for us to get such a reading, so that the invisible gas envelope surrounding the object could be studied, but again, it being in a distant galaxy coupled with the slow rate of orbital rotation of stars around a galactic center mass makes this a wait that could be billions of years long for such an event.
I agree that it is a very interesting object though.
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The linked PDF you provided speculates that "object X" might be a self-obscured star, obscured by its own ejecta.
If we assume that this is indeed a dyson swarm, then the purpose might not be exclusively for collecting energy.
A category II or III civilization would be doing asto-architecture, and would need tremendous amounts of raw materials. Heavy atoms are only produced naturally in one kind of environment: in the hearts of stars. If this star is regularly expelling large quantities of cosmic dust, as the linked article postulates, then it would make an excellent "Factory". Energy would be in copious abundance, and the star itself would be churning out millions of tons of heavy atoms every minute. Even with a short (compared to other stars) lifespan, it would make an excellent factory site for other large astro-engineering projects.
Yes, that was sort of along the lines of my thought. This seems like a poor location for a long-term agricultural project, but conceivably an excellent site for astroengineering. In that case there might be detectable byproducts (for example,as you suggest, the distributions of various elements might be depleted or rearranged). Also, they might use nuclear fusion to synthesize missing very heavy elements or for some other purpose requiring high energies (there is, after all, lots of gas as well), and that m
LHC (Score:2)
If you want to communicate with the other intelligent races in the Universe, go help the LHC.
Steps:
1) figure out physics
2) build the most promising communicator or detector
3) try, wait, try, wait, try, wait.
4) goto 2
We're making progress on step 1) but step 2) is far too premature at this point.
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Fermilab has been producing intermittent neutrino streams from their accelerator for some time now. Thatis probably a really good signaling device as they can be detected even with our current technology. The problem for us detecting something like that now is that we don't have directionality with existing neutrino detectors and imparting that might be rather challanging.
Certainly LHC is going to be producing more neutrinos as well.
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fun but pointless exercise. (Score:2)
The 'math' on aliens doesn't really work out in favor of them being anything we can comprehend, much less communicate with, even if you believe as I do that the existence of alien races is almost a mathematical certainty.
Here goes:
Age of universe, something around 14 gy (gigayears).
Age of earth, around 4.5 gy.
(Now, it's reasonably certain that the solar system is actually at least 'round 2' in this neighborhood - due to the presence of trans-iron elements, etc. At least one generation of stars in the area c
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The most logical ways I've seen of resolving this are:
1) There are no aliens, at least not of the tool using, technological, civilized, space-faring variety.
2) There were aliens; intelligence tends to self-destruct.
Or, my personal favourite:
3) There are aliens, but the galaxy is huge, and they stick to their own corner of it.
This third one makes sense if you assume that there is no "silver bullet" approach to interstellar spaceflight, and that it really would take the wealth of several planets to send a lar
Define intelligence (Score:2)
Will be slaves of an expanding culture like us or simply will try to enjoy their lives while it lasts? Intelligence don't imply culture, civilization don't imply changing their planet or solar system in a way visible from here.
I suppose that the question of if will ever be able to be surpassed the speed of light could matter here. If don't, will matter very little if we find something weird far away from here. And if the speed of light is not the limit, and they could figure how to surpass it in practice
Just send a colony ship. (Score:2)
If movies have taught us anything, it's that every colony ship ever is bound to encounter some form of intelligent life. Hollywood wouldn't lie to us, right?
Funding more important than brainstorming. (Score:3)
Alien Life Test (Score:4, Funny)
2) Neon light from dark side
3) Traces of THC in the upper atmosphere
4) SETI calls go into voicemail
Star Harvest (Score:2)
1) Intelligent life is fairly common.
2) We are somewhere in the middle of the bell curve advancement wise.
3) Really advanced races harvest stars for their energy and matter.
Thus, all we need to do is look for stars disappearing in an orderly fashion, and we've got the proof (and then we should hope like heck they don't stumble across our solar system with its moi
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Mod parent up
How to discover aliens in one almost easy step (Score:5, Insightful)
This step is simple: invent an FTL method of communication.
The reasoning is also simple. If we can have FTL then it is a given that all developed civilizations are using it. Radio is simply too slow. We don't use pigeons anymore to send messages, do we? So why do we expect an alien civilization to spend terawatts of energy and thousands of years to blast radio signals into space?
But if we can't have FTL then pretty much we are prisoners of our star system. Perhaps generation ships can export our genes to other stars, but that is unlikely, and we will never [in practical terms] know how they fared. Ping times of thousands of years are simply out of our time scale, until we all become cyborgs or beings of pure energy.
So that's why FTL is the only possible solution. Anything less is just a waste of money and effort. This effort should be invested into science, in every way possible. Even if FTL is absolutely impossible in our Universe, perhaps we will find a neighboring Universe with physical laws that are more to our liking.
There are 130 stars within 20 light years (Score:2)
Even if none of these planets have intelligent life, its still worth taking a look. A habitable world in another star system say 20 years travel away is hardly too far to "know what happened". A world in another star system that can support human life is a "game changer".
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A habitable world in another star system say 20 years travel away is hardly too far to "know what happened".
I'm not sure if we can develop a machine that can be sent for a 20 years (one way) trip and do all the research completely independently and efficiently. It actually is a job for an AI - we need better robots; another science problem right here. The main problem, however, is not technical - the trip will take 40-45 years, and youngsters who paid for it will be senior citizens when the probe returns
Pareto Principle (Score:3)
What an interesting post, I've thought the same things, especially about colonising our own solar system. Once we get there then we can try to figure out the next step of colonising the galaxy.
I was also considering a situation that *if* there were other civilisations that launched robots to explore the galaxy based on their own versions of AI could they combine over time. Could there ever be a situation wh
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The main problem, however, is not technical - the trip will take 40-45 years, and youngsters who paid for it will be senior citizens when the probe returns. Politically, in a democracy, the majority of population will not buy into this project. You need an enlightened dictator to do this.
Dictators are never enlightened. And democracies are perfectly capable of making long term plans.
Easy: (Score:2)
If our civilization is anything to go by, the uptake of fibre optics and low-power short range wireless communication means broadcasting high power transmissions was a brief abberation in history.
Obviously Interstellar communication by light is futile. At best a civilization may do in-system communication by high power highly focused laser beams. We may by chance catch a brief flash of coherent lig
Meet the aliens, a new comedy by Ben Stiller (Score:2)
We desperately want to meet the aliens. Unless they are illegal aliens, then they should GTFO.
Trailer Parks. (Score:2)
It seems that Aliens only want to address us by probing the rectums of trailer park inhabitants. It doesn't seem to be a stretch that Aliens are entranced by rectums and trailer parks.
If we concentrated our search for trailer parks, we are likely to find the places Aliens at least like to go on holiday; and that would be a start!
HIGH ENERGY interactions (Score:2)
If I were an advanced alien civilization, I'd probably need a lot of energy, and I'd probably be doing "star engineering" on a much larger scale than what's suggested here.
I'd modify a star to project its energy in focused beams, like the jets of a quasar.
I'd make a Project Orion powered by supernovae.
If I were a human looking for ETs, I'd look for signs of them in the highest energy interactions that we can see. Patterns? Events that don't appear completely random? etc
I wouldn't look for human-like ideas o
Simple: anything out of the ordinary (Score:5, Insightful)
Just look for anything out of the ordinary, and once you find it, try to come up with an explanation. This way you'll not only find life (if it exist) but also other interesting phenomena.
Look for change. (Score:3)
Change seems to be the only constant of life. Look for a change in atmospheric composition, in RF "noise", in anything we can measure really. The galactic equivalent of a motion detector. Not all change represents life, but it does represent something worth investigating. And, of course, the change might not be occurring on a scale we can measure in a short timeframe (where short would be less than our average lifetime), but it would almost certainly be faster than traveling anywhere with existing technology.
Anything else -- the absence or existence of certain elements -- is even more speculative than postulating a cause for change. The only exception might be something we can be reasonably certain hasn't occurred naturally, such as a signal carrying intelligence (modulation), which is the whole drive behind SETI. The problem with only looking for modulated EMR, is that it limits the domain to strictly intelligent life, which, while extremely interesting, could well be too high a threshold.
The other problem is that given the vast distances of space, anything we discover will be ancient history at best, and quite possibly long gone. The only way we're likely to actually communicate with another intelligent species is if they happen to be remarkably close by, or if one of us masters the manipulation of space-time.
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I was going to go with the large orbital rectal probe manufactory...
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would be, IMHO, a large black rectangular monolith in orbit against one of the outer planets...
Or when the little green men get off their silvery saucer-shaped craft and "have us for dinner".
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Stellar engineering!?! Any civilization capable of that would be capable of finding another planet.
And propulsion signatures, Really? What exactly would that look like?
The whole thing reads like someone watches too much TV.
Gases in the atmosphere are about the only thing that can be remotely sensed. But I'm sure someone could imagine a non-intelligent life form that could emit chlorofluorocarbons or just about anything else anyone would care to associate with civilization on earth.
And Dyson Spheres. Yea
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I don't think stellar engineering seems as difficult at interstellar travel. We have significant sources of hydrogen in-system, and building enough ships to evacuate the entire population is probably harder than building some simple machines to strip hydrogen off of jupiter and shoot it in the sun's direction.
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Of course I do not recommend WE do this, as Aliens may not be friendly.
But yet you suggest other civilizations might realize this is a great way to let others know, but be too dumb to realize the dangers?
The amount of sulfur needed prevents sustainability of such a project over the time span needed for detection by any other intelligent life forms. How often do WE do spectral analysis on any given random star?
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> Can we really extend the life of our own sun? I can't even begin to calculate how that would work...
Well, for one, we should start using it only when it's dark outside.
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Good luck with that.
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They are so full of shit they have massive amounts to spare.
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No, a "rational" society would look at the costs of interstellar travel and conclude that any attempt at a mission to another star was ludicrously overpriced and had absolutely zero practical value in any meaningful timeframe.
And now we know why suicide can be a rational choice.
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Ooh, I know this one: The Interstellar Raven. And the the Galaxy quoth: "Nevermore!"
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Almost sounds like, aptly enough, Quarantine [wikimedia.org] by Greg Egan. Though I could have sworn there was another novel with a similar premise. (Herbert, perhaps?)
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David Brin, Crystal Spheres
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A Dyson Sphere would block visible light, but radiate in the infrared with just as much energy as the star it encloses. What you'd see from a distance is a stellar object too cold and too large to be a star, but still highly visible.
But this assumes that anyone out there is crazy enough to build one of those things in the first place.
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A Dyson Sphere would block all light but a massive structure like in Ringworld would cause a dim band around a star rather than the brief dimming that means simply there's a planet. There's no known natural object that would block a region of a star for an extended period. A tight asteroid belt would cause dimming but not block most of the light. Look for a star with a significantly dimmed region or one that appears to be in two parts. Current telescopes would more than likely see most stars are solid even if there was a dim band so when higher powered ones become available it could be another thing to look for.
Luc Arnold looked into this [obs-hp.fr] and concluded that
Multiple artificial objects would produce light curves easily distinguishable from natural transits.
He is including structures like the Ring World (or the Culture's Orbitals) in such "multiple artificial objects."
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Who would want to detect us?
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Not me... (holding nose).
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