Detection of Earth-like Civilizations in Space Now Possible

Mr. McGibby writes "Astronomers have come up with an improved method of looking for extraterrestrial life with an Earth-like civilization. Theorist Avi Loeb proposes to use instruments like the Low Frequency Demonstrator (LFD) of the Mileura Wide-Field Array (MWA), an Australian facility for radio astronomy currently under construction. The array could (theoretically) detect civilizations broadcasting in the same frequencies as our own society. From the article: 'Loeb and Zaldarriaga calculate that by staring at the sky for a month, the MWA-LFD could detect Earth-like radio signals from a distance of up to 30 light-years, which would encompass approximately 1,000 stars. More powerful broadcasts could be detected to even greater distances. Future observatories like the Square Kilometer Array could detect Earth-like broadcasts from 10 times farther away, which would encompass 100 million stars. ' The original paper describes the details."

Comments

Knowing Your Neighbours

[Renegade Lisp]

I think this is a great project. But step back for a moment and think what it means: If there was an earth-like civilization even very close to us, say, at Alpha Centauri, we've had no chance of detecting their stray radiation up until now. And with this new program, it's only within 30 light years that we might be successful. That's really our very, very close vicinity.

This, I think, puts the fact in perspective that SETI@home hasn't found any signal yet, even after years of listening. They would only be able to detect very powerful transmissions, much more powerful than anything our own civilization could produce.

The fact that we haven't found any artificial signals from space yet doesn't mean there's nobody out there.

Re:Knowing Your Neighbours

[metlin]

The fact that we haven't found any artificial signals from space yet doesn't mean there's nobody out there.

And to quote Carl Sagan, "Absence of evidence is not evidence of absence."

Re:Knowing Your Neighbours

[Minimum_Wage]

The flaw with all these searches is that it assumes that any nearby civilizations are exactly at the same level of development as humanity. Isn't high-power broadcast radio actually declining on Earth right now in favor of cable, fiber, and low power systems like the small satellite DBS dishes? If an alien civilization isn't in the same +/- 50 year technological window as we are, we'll probably never hear them even if they are next door. Still, if you don't look you'll never be sure...

Re:Knowing Your Neighbours

[oliverthered]

But that still means that there could be nothing out there
And he stretched out his noodly appendage

Re:Knowing Your Neighbours

[zippthorne]

Ridiculous. It depends on just how much evidence you don't have. For instance, there's very little evidence of the existence of Yeti despite some rather concerted efforts to find anything at all. In fact, there is no evidence at all. Yet mountain lions are easy to find evidence of. Therefore yeti are far less likely to exist than mountain lions.

Absence of evidence is prima facie evidence of absence.

The question is, does your lack of evidence result from failing to look or from nothing turning up despite exhaustive searching?

Re:Knowing Your Neighbours

[Gulthek]

That depends on how you are searching. Searching for your keys in a cluttered room with the lights off is going to be difficult, and you may look for quite some time without being able to conclude that the absence of evidence is evidence of the keys' absence.

Re:Knowing Your Neighbours

[silentounce]

This argument has come up several times. If you RTFA then you will see this: "On Earth, military radars are the most powerful broadcast sources, followed by television and FM radio. If similar broadcast sources exist on other planets, facilities like MWA-LFD might detect them."

TV and communication media are not the only sources of radio waves. It would stand to reason that most civilizations that develop flight will eventually develop radar. Radar is very simple and reliable. Yeah, I know that there are stealth technologies, but commercial jetliners aren't using them. We'll probably be using radar for a very long time. Plus, radio is our current means of communicating with our spacecraft(isn't it? I may be wrong). If the society is space faring, and they have a well-developed space program, that may be a large source of radio waves that won't even have to escape an atmosphere.

Re:Knowing Your Neighbours

[div_2n]

Your assertion is just wrong. Human beings are indirect proof of the possibility of intelligent life elsewhere. The fact that we haven't found/been given/detected evidence is immaterial.

Regardless, you are attempting a negative proof or proof of impossibility. This is a logical fallacy. Interestingly, it works both ways. You can't prove a Yeti doesn't exist or that life (intelligent or otherwise) exists on other planets because you don't have evidence and vice versa. People can't prove either exist for lacking evidence. While the Yeti argument is another kettle of fish since life on earth is indirect evidence of life on other planets, it is a bit of a stretch but can be argued that the different primate groups are indirect evidence of the possibility.

Interestingly, Yeti and ETs share the distinction that there exists no clear evidence of either. It is possible that we will never have proof of the existence of either. Equally, we will likely never exhaust all possibilities to satisfy ourselves that neither definitely don't exist. Unless we plan on leveling all forests, excavating every square inch of earth (for archaeological evidence) and visiting every solar system and planet in the Universe. Both of which are equally absurd.

Re:Knowing Your Neighbours

[multipartmixed]

> Plus, radio is our current means of communicating with our spacecraft(isn't it? I may be wrong).

No, we use quantum entanglement for long-distance communication, and gravity waves for short-distance (say, under 5 light years). Radio is too slow for the distances involved.

Re:Knowing Your Neighbours

[exp(pi*sqrt(163))]

For a slightly more formal treatment see here. Sagan was talking out of his ass when he said that and there's nothing more annoying than people who keep quoting it.

Re:Knowing Your Neighbours

[peragrin]

I forgot the name of the species of fish but scientists thought it to be extinct. For years the evidence pointed to the fact that the particular fish no longer existed, yet one day a fisherman caught one.

A lack of evidence either way doesn't mean it doesn't exist. There are numerous example of animals that hide first. The possum "plays" dead. An animal intelligent enough to hide from other species isn't unheard of. Given the right locations on earth, two mountainous and relatively uninhabited area's. It is possible a yeti, and big foot exist.

of course that being said I won't believe it until I see it, but that doesn't mean it's impossible, just improbable. That's a huge difference.

Re:Knowing Your Neighbours

[rleibman]

And to quote Carl Sagan, "Absence of evidence is not evidence of absence."

I'll take your quote and raise: "Extraordinary claims require extraordinary evidence"

Re:Knowing Your Neighbours

[exp(pi*sqrt(163))]

You are confused about the meaning of the word 'evidence'. When you obtain evidence of X you shift your estimate of the probability of X upwards. That's what 'evidence' means. You need to get this distinction.

You say "you are attempting a negative proof or proof of impossibility" which demonstrates you didn't actually read or understand the parent post which stated, quite clearly, "Absence of evidence is prima facie evidence of absence.", not "Absence of evidence is prima facie proof of absence". Until you sort out the difference between proof and evidence the rest of what you say is moot.

Re:Knowing Your Neighbours

[Reducer2001]

Coelacanth

Re:Knowing Your Neighbours

[cnettel]

Coelacanths. A specific species within a large group was found in 1938. Established science had assumed them to be extinct, simply because the last fossil records were 70 million years old or so. No European had gone out of their way to really look for it, and when a reward was announced and the news of it trickled out, it was discovered that it was known to exist in the seas around the Comoros.

Re:Knowing Your Neighbours

[mysticgoat]

"What are you doing?"

"Looking for my keys. I dropped them somewhere between the house and the car."

"But then why are you looking here? This isn't between the house and your car."

"Well, because its too dark to see them over there. I'm under the street light here. So if they somehow bounced this way, I just might be able to find them."

And so goes the SETI research, up until now at least.

Re:Knowing Your Neighbours

[JavaLord]

that assumes they want to find us, or even find us worthy of contact. They may have found us already, reported back to their homeworld, and decided we're not worth their time to look at, maybe we're too far, (could take them a long time to get here) could be we don't (didn't) have a sufficiently advanced civlization. And heck if the probe took 250,000 years to find us, who's to say that the originating civilization hasn't given up, or disappeared, died out, sun went nova? who knows. and if it takes 500,000 years to search the galaxy, well, human civilization hasn't been around for nearly that long, we could have been one fo the first looked at 500,000 years ago, and found to be inhabited by all kinds of animals.

The other thing funny about assuming things about our hypothetical aliens is that we assume they have our same lifespan. While 250,000 years is a long time to us, maybe it's only a few generations to them? Or maybe it's much longer to them and they have lifespans of only 10 years....It's just impossible to know these things, but it's fun to speculate.

Re:Knowing Your Neighbours

[exp(pi*sqrt(163))]

Dictionaries are hopeless for providing definitions in even a slightly technical domain. Almost every definition of "evidence" in a dictionary is hung up on the notion of proof, probably because of the common legal use of the word. For this reason dictionary definitions tend to define 'evidence' in terms of 'proof'. But read just about any scientific literature - you will find many uses of the word 'evidence' but very few uses of the word 'proof'. In fact, 'proof' is something of a taboo word in scientific circles outside of mathematics. The notion of 'evidence' in scientific discussion is quite separate from the notion of 'proof', and its meaning is close to what I originally said: that which tends to increase the assessment of the likelihood of something. Carl Sagan's quotation is fine for legal discourse, but it's way off the mark for scientific discourse, the domain for which it was intended. Even in informal technical discussion the word 'evidence' ceases to carry the sense of being the thing that clinches the proof.

In science, proof is a very rare thing. All we have are hypotheses that are more or less likely, and evidence that makes them so.

Re:Knowing Your Neighbours

[egyptiankarim]

Universes Worst AIM Conversation Ever... EarthDudez: Hey! Waz up? [30 years later] GrayGuys: Nothing much... u? [30 years later] EarthDudez: brb [400 years later] EarthDudez: back! [30 years later] GrayGuys: your moms back. [30 years later] EarthDudez: lolz. dude you're so GrAY! [30 years later] GrayGuys: lol

Re:Knowing Your Neighbours

[bob_herrick]

Turn your point around. Assume that evolution of intelligent life is, if not routine, at least reasonably possible. No other intelligent lifeform has, to the best of our knowledge found us, and we have been detectable for several decades (say 30 to put it into the detection context of the article). Doesn't that suggest that the other explanation is not that intelligent life is not out there, but that detection technology is hard?

Re:Knowing Your Neighbours

[HiThere]

Well, the lifespan has to be approximately right. It could be longer, but much shorter and there isn't that much reason to evolve intelligence. Mind you, if they run their bodies hotter or colder this is subject to variation. (Chemical reaction speed being thermally determined.)

If their lifespan is longer, one needs to wonder what part of their lifespan is longer? Childhood or adult? It would make a big difference as to their nature. Long childhood would lead to more flexible thinkers. Long adult would lead to great emphasis on stability (presuming both adults were charged with rearing the children). OTOH, if intelligence were a sex linked display, like a peacock's tail, IP would be EXTREMELY jealously protected...and the non-displaying sex would be relatively (grossly?) stupid.

A large part of what we are is determined by evolving in small groups of individuals who were close kin to each other. Without this we probably wouldn't have evolved altruism or mercy. It's still rather unreliable, but we exhibit more of it than almost any other animal. As it is, it is sufficient to enable us to evolve rather complex societies. (We *do* need to keep a constant eye out to prevent cheaters. [Mr. Gates.] But this is the expected result from game-theoretic simulations.)

Do we assume the same thing for aliens? How else could you evolve a planetary civilization? Is THAT the answer to Fermi's paradox? ("Where is everybody?")

Re:Knowing Your Neighbours

[Mozk]

Still, never hurts to check...

It does hurt when the funding, research, and effort could be put to better uses. We ought to work on our needs such as learning about our own planet (there's so much that we don't know), and how our species is going to survive, since at the current rate, survival could become a problem fairly soon. What we shouldn't be worrying about is philosophical questions like if there is life on other planets or the infamous "are we alone?" Sure, finding life on other planets can give immense insight into, among other things, how life is created in general and not just on Earth, but we might want to get to a stable point in society and survival where we're able to take time to study it. It also seems somewhat foolish to be looking at other parts of the universe since we're not able to travel anywhere in a resonable amount of time (reasonable as in under 10000 years) unless we develop ways to travel at large fractions of the speed of light. Even then, outside of our galaxy, the next closest galaxy is millions of light-years away, and the information we've received would be millions of years old. Knowledge is great and everything but the search for extraterrestrial life seems very pointless, especially at our current state.

Re:Knowing Your Neighbours

[theTerribleRobbo]

And to quote Carl Sagan, "Absence of evidence is not evidence of absence."

Carl Sagan has obviously never had to deal with a HR department.

"Earth-like" civilizations?

[TheWoozle]

Great...

So we're going to pick up an alien version of "The View"?

Re:"Earth-like" civilizations?

[j00r0m4nc3r]

I think perhaps we already watch the alien version.

Re:"Earth-like" civilizations?

[SnapShot]

Even scarier... in 2 years all the galactic civilizations within 30 l.y. will be able to catch the original broadcast of The Dukes of Hazzard.

Re:"Earth-like" civilizations?

[ncc74656]

So we're going to pick up an alien version of "The View"?

With Jabba the Hutt instead of Rosie O'Donnell? Oh, wait...

any physicists out there?

[Lord Ender]

Could you list any of the current areas of research which may some day allow for information transmission faster than c? Let's keep in reasonable: only mention theories we may be able to explore within the next 1000 years.

Re:any physicists out there?

[MindStalker]

Only if you redefine c. Theoretically c can be increased in some special situations such as extremely high gravity fields and other things. But in general traveling faster than c reverses cause and effect, which can't happen. Though one may eventually figure out how to jump from one side of the universe it wouldn't be traveling per say.

Re:any physicists out there?

[inviolet]

Isn't there something to do with the spin of an electron, which when you reverse the spin, immediately reverses the spin of some other electron, with no delay? Couldn't you reverse the spin of a bunch of electrons on earth, and have their counterparts match the reversal, 30 light years away. It could be used for exchanging information at faster than light speeds.

You are thinking of quantum entanglement, aka "spooky action at a distance".

It cannot be used to transmit information. Think of it this way:

1. You take two slips of paper, one black and one white, and put them in envelopes.
2. You randomly select an envelope and mail it to your brother in Poughkeepsie. You keep the other envelope for yourself.
3. While the envelopes are in transit, nobody has yet observed their contents (i.e. their spins). Yet you know that their contents (their spins) must be opposite because they are an entangled pair.
4. The envelope travels to Poughkeepsie at the speed of light, or significantly slower in the case of the US Postal Service.
5. Your brother receives and opens his envelope. He observes that his slip of paper is black. The uncertainty collapses: he now instantly knows that your slip of paper is white.

Notice that you cannot send actual information by this route. The uncertainty of "which slip of paper is in my envelope?" collapses instantaneously, but it collapses into a random choice. Neither of you could know in advance which color you would find in your envelope.

This illustration changes slightly when executed at the quantum level: while the envelopes were in transit, both slips of paper were actually grey... though some might insist that they were both all possible colors, until they were finally observed.

Re:any physicists out there?

[infinityxi]

I believe you are talking about Quantum Physics but the problem with that would be that you couldn't really send coherent information out. You have 2 particles and once you "know" the spin of one particle you "know" the spin of the other. To alter the spin of a particle would contaminate it, because you would have known what the spin was to reverse it. I could be wrong, and I think actually there is some method using 2 pairs of particles to transmit information but I'd have to look it up it was all theory in Brian Greene's "Fabric of the Cosmos" (Good Read) but using the method you describe there is no way to send a message.

Re:any physicists out there?

[TopherC]

The history of this feature of quantum mechanics is fascinating!

Einstein, Podolski, and Rosen proposed this as a thought-experiment to show that the hocus-pocus in quantum mechanics was silly, and that really the envelope always "knew" what color paper was inside it. They used this setup, together with the understanding that nothing could travel faster than light, to show that the envelopes always had definite papers inside just like you'd imagine, which also means that quantum mechanics is an incomplete theory.

But (much later, in the 60's) Bell thought about extending this thought-experiment a little bit, and proved a theorem relating to it: Bell's inequality. This actually proved that the envelope's contents were in fact indeterminate before being inspected, and that quantum mechanics is a complete theory -- you can't do better. Bell's inequality was experimentally tested, decisively in the 70's. The results agreed with Bell's inequality, and therefore confirmed quantum non-locality. It seems now that Einstein's original idea was turned around and used to prove him wrong (or nearly so)!

Although proving and understanding Bell's inequality is just a little bit challenging (but no problem for a physics undergrad), David Mermin came up with a specific, clever example of this inequality that is easy for anyone to understand.

Wikipedia has a pretty good section on Mermin's exemplary experiment:
http://en.wikipedia.org/wiki/Bell's_Theorem#Exampl e_for_Bell_Inequalities

I probably can't explain this idea any better Wikipedia. There's an even more lucid description of this in Brian Greene's "The Fabric of the Cosmos", around page 107.

So the original idea of sending off two letters, one with a black paper and one with a white one, is not meant to illustrate quantum entanglement. But it does serve to illustrate how information in this case cannot be transmitted. Even if one envelope seems to know instantaneously when the other one was opened and how, that still doesn't really require the transmission of information. I guess it's because the order in which the envelopes are opened doesn't matter.

Hope that helps.

Interesting idea - but same old problem

[SNR monkey]

How can we be sure that extraterrestrials (if there are any) are broadcasting radio waves? What makes us think they would be communicating in an 'Earth-like' way?

Impossible!

[LiquidCoooled]

The Recording Industry Galactic Alliance (RIGA) mandated that no radio signals shall leave the atmosphere of any planet.

The respective governments all attempted to stop this legistation getting in but the RIGA had bigger guns!

Obligatory

[inviolet]

And I, for one, welcome our new nearby, low-frequency-emitting overlords.

And I would like to remind them that as a net.geek, I could be useful in rounding up others, to toil in their oneline goldfarms.

Let's hope they're not like us

[orson_of_fort_worth]

The signals we'd pick up from a civilization similar to ours would be viagra spam and Saved by the Bell reruns. So disappointing it might set back space exploration by centuries.

Re:Let's hope they're not like us

[kfg]

The signals we'd pick up from a civilization similar to ours would be . . .

. . ."Send more Chuck Berry."

KFG

Window of opportunity

[TubeSteak]

How long do "earth like" civilizations put out RF energy that is detectable from space?
How long will we keep doing it?

Searching for XYZ years worth of RF in a bubble 60 light years across doesn't strike me as very promising.

Re:Window of opportunity

[buzzzz]

Actually it IS a big deal. It's been said by someone that if their exist two of something than there probably exist several of it.

If primitive life forms are discovered on any planet other than Earth, there would be an astronomically higher chance of there being primitive life on several planets across the universe and thus an astronomically higher chance of intelligent life out there.

It would, I hope, motivate a renewed search for life in the universe.

It's already too late ?

[Rastignac]

You can't detect "Earth-like radio signals from 30-light-years-away stars" anymore. Because of the 1979 song "Video Killed the Radio Star" from the Buggles (see
http://en.wikipedia.org/wiki/Video_Killed_the_Radi o_Star for more information).
So now we should check for video signals from these stars ! ;)

Not a big area

[Orange Crush]

30 or even 300 LY is tiny on a galactic scale. Then again, anybody who's more than 30 ly away won't be able to have a meaningful conversation with us over the course of a single researcher's lifetime . . . unless of course they're kind enough to send instructions on how to communicate FTL.

Speaking of FTL communications . . . maybe civilizations only use radio for a relatively short time in their development. Present understanding of physics pretty much rules out FTL communications, but there could always be some exotic aspect of our universe we haven't discovered yet that would allow it and we'll finally be able to log in to the giant IRC server of the universe.

Re:Not a big area

[David_Shultz]

anybody who's more than 30 ly away won't be able to have a meaningful conversation with us over the course of a single researcher's lifetime

Are you joking? Do you not think it would be meaningful just to receive the message "hello"? this would be one of the most important moments in the history of humankind (not to mention alienkind). A long conversation isn't needed for this to be meaningful. Heck, no conversation is required -we just want to find someone else out there.

Re:Not a big area

[Penguinshit]

Hopefully the message wouldn't be "All your base are belong to us."

What does "Earth like" mean?

[soft_guy]

Would this method have detected our civilization in the 1800s? 1910? 1930? 1950?

What exactly is it detecting? FM radio? Television? Radar? Emissions from cars? Would it detect a working telegraph?

Re:What does "Earth like" mean?

[sentientbeing]

On Earth, its more likely the lower frequency fields radiated by all the mains cabling and power sources that would be easier to detect.

Re:Hmm.

[cmdr_beeftaco]

How will i listen to my ipod in my car if FM transmissions are obsolete?

Re:Hmm.

[silentounce]

"Given the massive distances between stars, astronomical mass extinction theories, and the time evolution takes, aren't the odds of two technically advanced civilizations being around at the same time...umm astronomical? :)"
 
The true probabilities are not known. We don't know how common life is. We don't know how often a mass extinction of life occurs. We don't know how long evolution takes except for on our one world. We don't have enough data to accurately predict whether or not life is rare or common in the universe. Another perspective could be that it is in fact more likely that advanced civilizations would be around at the same time if the universe has a consistant timeline. If the way that life-harboring star systems form, the way that life itself forms, and the way that intelligent life evolves is analogous across the universe then this may be the Golden Age of intelligent life throughout our galaxy.

Re:Hmm.

[MindStalker]

Exactly, though its a given that if an alien civilization more advanced than use WANTED to be found they would use multiple technologies radio being one of those. Radio would most likely be a baseline technology that any advanced civilization capable of interstellar communication would have already reached.

if we're only now uncovering this new technology..

[laggist]

..they probably know where we live by now :/

Faster than Light Communications

[Glacial Wanderer]

broadcasting in the same frequencies as our own society

I think the real issue isn't frequency, but technology. Personally I believe there must be a practical way to transmit data at faster than light speeds. We've been using the EM spectrum for transmitting for just over 100 years. If there are better methods of transmitting data, not only will our search area be limited, but we'll be searching for is possibly a short lived technology.

my question is...

[jimstapleton]

Do we have the tech to set up a powerful and focused transmitter that would be recievable by standard radio devices on a planet (if we find one) that far away?

I can see it now.

"Citizens of Earth, the Xibian Communication Commision (XCC) is ordering a Cease and Desist of projection of signal on channel 88.6. Failure to follow this within the standard grace period of 1 Xibian day will result in fines of 100 Toriks per Xibian Day. Given that you are 50 Xibian years distant (as light travels), at 250 Xibian days per year... It really sucks to be you."

Listening for radio waves is futile

[rhartness]

I've always considered these types of projects pointless. It's not because I think that we are necessarily alone but because the use of radio waves for communication seems like such a simple and quickly evolvable technology that we would never find them. Here's my reasoning.

Let's assume that we are a 'typical' univeral life form. I'm haven't brushed up on my radio broadcasting history but I'll assume that we've been broadcasting information in some form since the 1910's. Let's now say that for the next 400 years we use this type of technology to communicate. I think that is a very large estimate, though. By that time the human race will have progressed so far (IMHO) that we will need much quicker and reliable forms of communication because of advancements in space travel and that type of communication will even trickle down into normal, everyday communication on earth. Using all modern forms of communication will not suffice if we have bases of operation even as close as our nearest star. I don't know what it will be, but a solution will provide itself and I doubt it will be anything close to what we have now.

So, Let's assume then that we as humans use radio waves for 500 years, total. If you want, give or take an extra couple 100 years. It doesn't matter for the point I am trying to make. If we only use radio waves for a span of 500 years, than that amount of time is a drop in the bucket compared to the entire, vast expanse of time that has past in our universe.

If there is another civilization out there. I'm pretty sure that they are either way behind or way ahead of us in technological advancements. If they progressed at even a fraction of the rate that we have (and will), then the span of time at which that have transmitted any type of communication that we can currently understand and interpret is so short that it's a practical impossiblity that we will 'catch' it. Don't get me wrong, I'm not saying that the entire search for intelligent life in space isn't important. I'm just saying that the current technology that we have is in such an infantile state that it's a waste of time and resources that could be put towards better works of science.

Fiber to the Home.

[crhylove]

Unless alien civilizations are just as beholden to corporate interests and backward technology as we are (which I doubt, and if it is the case why should we bother communicating with their ignorant asses anyway?), I would assume their civilization has fiber to the home, and I doubt their wireless controllers, cell phones, and remote controls are going to have a signal that gets off the planet at all.

If we were REALLY interested in contacting alien civilizations, we would make our own much more attractive first. I doubt any alien civilization is going to be interested in sharing technology with a planet of retarded monkeys that give morons like Bush who openly admit talking to invisible men in the sky nuclear weapons.

As a matter of fact, I can't imagine any advanced civilization bothering with the kooks who live here and believe in such ludicrous stone age fantasies. Particularly kooks with nuclear weapons and who engage in water-boarding.

I'm so ashamed of our whole species I can't even begin to imagine why *I* bother interacting with them, much less some aliens who weren't so unlucky as to be born in this idiotic power-structure of ignorance.

rhY

Re:Fiber to the Home.

[cowscows]

Thank you, those are some very useful comments. I'm sure that all the astronomers out there, having read your post, are preparing their resignations, and will instead focus their time on solving all of the world's troubles. Thank you again, for bringing these issues to our attention.

Re:Fiber to the Home.

[Simetrical]

You're using a definition of "advanced" rather at odds with what everyone else here means by "advanced". We're all talking about technologically advanced, whereas you seem to be talking about morally advanced. But that seems like an odd thing to expect of aliens in any case: surely their morals would be dramatically different from ours?

It seems strange to expect that very many aliens would disapprove of torture, for instance. Why would they? We haven't, up until perhaps fifty to a hundred years ago. You can make a convincing Machiavellian argument that the ends justify the means and a few probable (even if not certain) terrorists' suffering is justified. That kind of argument is mostly out of favor now, but I very much doubt it would be if we were, say, ants.

Well, what are we looking for...?

[MetaPhyzx]

Essentially, we're looking for someone "out there" that thinks/acts/interacts with their world the way we did with ours. It's almost identical to looking for carbon based life forms like us, on other worlds (Mars as an example). I understand that it's easier to start looking for what you already know, but with the variance of life and how we interact/communicate just on this planet, maybe we can think a bit more outside the box?

30 light years

[iminplaya]

That means we should be picking up their "70s Show" right about now.

Aliens

[darknite1979]

I think it would be foolish too assume that we are the only life in the universe. The problem with finding life is that we really dont know how common life is in the universe. I recently saw a website http://www.anzwers.org/free/universe/index.html that can give very good perspective on just how big the universe reaaly is. Either an alien species has already detected us and is waiting for the human race to cause its own extinction (which I am sad too say is likely at this point) or they are so advanced that they reaaly dont care about us in any way.

intelligent life on earth?

[peter303]

From the way be behave, I wonder.
Remember Star Trek IV when the aliens though just the marine mammals were intelligent.

Whoa, there...

[Rob T Firefly]

improved method of looking for extraterrestrial life with an Earth-like civilization

Do we really want to find something Earth-like? I for one would rather find someone who's got it right. We need a wise older sibling, not an equally dysfunctional twin.

I could just imagine the space phonecalls..

EARTH: Hey, guys. How's it going?"
ALIENS: Well, our environment is crapping itself, we're all trying to kill each other, and we still won't grant marriages to every couple who wants one.
EARTH: Yeah, same here. Any, you know, wise alien tips for us?
ALIENS: Well... have you invented Reality TV yet?
EARTH: Yep, doesn't seem to have helped much.
ALIENS: Have you, I dunno, tried invading someplace oil-rich?
EARTH: Done that, lots of times.
ALIENS: How about starting arguments about the origins of your own species?
EARTH: Oh hell, don't get me started on that can of worms buddy.
ALIENS: Well, try inventing a couple of new incompatible game consoles...

A Cover Letter to Our Neighbours

[PHPfanboy]

Hi,

I tried to leave you a voicemail a couple of light years ago, but haven't heard back so I'm taking the liberty to approach you out-of-the-blue.

The President of Earth is planning a road trip in your region over the next few eons and we're looking to set up strategic meetings with partners and potential reference enterprise star systems to grow our activity in your area. As we grow our unique blend of factional religious wars, fossil-fueled planetary suicide, coca-colonial capitalism, short sighted foreign policy, anti-social youth, teenage pregnancy, drug trafficking, blood diamonds and illegal arms transfers we're looking for partners in our long run success.

If you would like to arrange an introductory meeting with our President, we'll show you how you can implement our unique flavour of self-destruction.

RSVP by radio please.

Mr. L. Presidente

------------------------

Seriously, why should anyone want to hear from us? can't we leave these poor fuckers alone?

At last !

[Salsaman]

At last we will be able to receive "Single Female Lawyer" !

Technology trends from our own planet

[east coast]

More powerful broadcasts could be detected to even greater distances [over 30 LYs].

Maybe I'm wrong but I would think that as a civilization becomes more advanced that the power of their broadcasts would decrees and the signals would become more focused. Would it be easier to detect a signal from 20 years ago from a few light years away than what it would be to detect today's signals? If so I think we'd be looking at a small window of opportunity to detect another civilization.

This isn't to say that widening the spectrum of the search is a bad thing but I'm just trying to get my head around how useful this might really be.

Re:Hmm.

[JCOTTON]

"but I could see FM radio being obsolete 100 years from now...

What the hey? I am still using spark gap and CW Morse Code. No, once a technology is in place, it rarely is completely eliminated. Some people still ride horses, ride bicycles, hike, etc, even though they have cars. I use CW even though I have SSB and digital modes available (and a lot of people do also). By the way, FM is already obsolete. Right now that is.

Optical SETI is the way to go

[TheSync]

Optical SETI with intense nanosecond light pulses is the way to go, forget radio!

1. Visible light-emitting and detecting devices are smaller and lighter than microwave or radio-emitting devices.

2. Visible light-emitting devices produce higher bandwidths and can consequently send information much faster.

3. Interference from natural sources of microwaves is more common than from visible sources.

4. Naturally occurring nanosecond pulses of light are mostly likely nonexistent.

5. Existing lasers can produce nanosecond pulses that can outshine a star by 30 times.

http://observatory.princeton.edu/oseti/oseti.html

A long, boring, convoluted logical argument

[duh P3rf3ss3r]

You are exactly right and I can't believe all of the people who are just so wrong on this.

It's very much like this.

Joe: All swans are white.
Jill: What evidence do you have?
Joe: I saw a swan and it was white, hence, all swans are white.

Any of us looking at this would see that Joe's assertion is unproven. The absence of a non-white swan in Joe's search is not proof that non-white swans are absent, if you'll pardon my tortured language for illustrations's sake. Now:

Joe: All swans are white.
Jill: What evidence do you have?
Joe: I've inventoried 1000000 distinct, separate and individual swans and each and every one of them was white, hence, all swans are white.

Now, there are those among you who would feel that Joe's conclusion in this second scenario is better supported (i.e. more evidence) but that's simply false. The only evidence that Joe has amassed is that, within the space Joe has searched and during the period of his search, white swans certainly out-number non-white swans. Joe has come no closer whatever to evidence that all swans are white because, in both the first and second scenarios, finding just one non-white swan invalidates Joe's hypothesis.

Hence, an absence of evidence as to the existence of non-white swans is not evidence of the absence of non-white swans. It is always possible that the next swan Joe examines from the pond across the hill will be a non-white swan and it will invalidate Joe's hypothesis in one fell swoop. It doesn't matter whether Joe has examined one swan or one million swans, such is the case.

Now, there may come a time when Joe has entirely (or practically) exhausted the available search space (e.g. looked at each and every swan on the planet.) What then? Well, then we may be tempted to argue, and many might agree that, once the reasonable search space has been exhausted, Joe can say that absence of evidence is evidence of absence.

For those of you who think this message is already far too long, perhaps we can agree to stop here and, for practical purposes, stipulate to that. But, by any measure, the reasonable search space for ET is far from exhausted. In fact, at this stage, we are very much like Joe when he had examined just one swan and tried to use that as evidence that all swans are white. Hence, I maintain that Sagan's statement, applied to SETI, is logically flawless.

Now, if there is anyone out there who's bizarre enough to be enjoying this, let's examine the case of where Joe has exhausted the reasonable search space for swans and has still failed to find a non-white swan. Is this evidence that all swans are white? Well, in reality, no. It certainly suggests that non-white swans are exceedingly rare in comparison to white swans. But there is always the possibility that there will be a very rare recessive gene or perhaps a random mutation that will produce a non-white swan tomorrow within the space that Joe has already searched. Hence the absence of evidence for non-white swans proves absolutely nothing -- nothing -- in any rigourous sense, about the absence of non-white swans.

That's why scientists are trained to avoid forming hypotheses like "all swans are white" because that statement is, essentially, unprovable and unprovable can logically be shown to be functionally equivalent to unfalsifiable.

A better hypothesis would be something along the lines of: "In a random sample of 100 (or 1000 or whatever number the granting agency gave you a budget for) swans, the incidence of non-white swans will not be significantly different from zero (or less than 1% or 5% or whatever number you think you need to specify in order to secure the grant.)"

QED