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

[VJ42]

This, I think, puts the fact in perspective that SETI@home hasn'tfound any signal yet, even after years of listening. They would onlybe able to detect very powerful transmissions, much more powerful thananything our own civilization could produce. Never mind what SETI are doing, the STI (Search for terrestrial intelligence) project havn't found much here on earth yet! ;)

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

[Viol8]

"If they were really interested in finding and contacting us, they would have done so by now"

Some people say they already have! Though why they only ever contact toothless rednecks in pickups in Arkansas at nighttime on lonely roads is perhaps a mystery for another day.

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

[atrocious cowpat]

Lrr just called from a very, very close vicinity (adjacent to a place) and he decidedly wants to know what happened to the single female lawyer and her compellingly short garment.

Re:Knowing Your Neighbours

[bonoboboy]

This, of course, is assuming that said possible civilization even discovered high-power broadcast radio. They may have discovered something else entirely that worked better for them. :D

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

[ArcherB]

The flaw with all these searches is that it assumes that any nearby civilizations are exactly at the same level of development as humanity

Actually, they would have to have been as advanced as we some time ago, depending on how far they are away. For example, if they are 500 light years away, then they would have to have been at our level 500 years ago, or at least be using radio 500 years ago.

Re:Knowing Your Neighbours

[1u3hr]

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?

TFA mentions not just communications radiation, but things like radar. It's hard to imagine radar not being used for a long time into the future. Though as a general rule, as any technology develops, it should become more efficient and thus less will be wasted by flying off into space.

Re:Knowing Your Neighbours

[Mr Z]

Hmmm... how many other long-distance forces are easily modulated and detected? Electromagnetic waves are pretty much the only game in town given the physics I'm aware of. I can't imagine, say, using gravity to implement the equivalent of our radio—too much energy required to move the transmitter, and requires too sensitive of a detector to receive. I guess maybe they could work out something that used quantum entanglement...

Now the real question is, will we instead end up finding a planet or other large body 25-30 light years away that's effective in sending us back our own broadcasts of I Love Lucy and Leave it to Beaver?

--Joe

Re:Knowing Your Neighbours

[oliverthered]

But that also tells you things about what you are looking for, e.g. you didn't buy keys with a glow in the dark keyring.
SETI tells us that there little chance of extramly high powered radio signals being beamed accross space from other civalisations.

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

[carn1fex]

Yea although we can all think of a 100 reasons why the possibility of detection is pushed down to 0.00000000001%, if the hardware is already in place to give a look, then hey, why not.

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

[jamstar7]

Coelcanth (sp), IIRC, back in the 50's. Thought to be extinct for about 50 million years.

Wonder if they go good with lemon & butter...

Re:Knowing Your Neighbours

[Reducer2001]

Coelacanth

Re:Knowing Your Neighbours

[jamstar7]

If they were really interested in finding and contacting us, they would have done so by now

Some people say they already have! Though why they only ever contact toothless rednecks in pickups in Arkansas at nighttime on lonely roads is perhaps a mystery for another day.

'Talent' scouts for the intergalactic version of Springer?

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

[Chris Burke]

The flaw with all these searches is that it assumes that any nearby civilizations are exactly at the same level of development as humanity.

It also assumes that 'level of development' is a linear progression and that they would necessarily develop the same technologies as we have. On an alien world, an alien lifeform may have completely different needs and thus completely different technology. For example, ocean-based life can already communicate over long distances using audio waves. Life on a venus-like world may be unable to use radar due to the atmosphere. And so on and so forth and just use your imagination.

Still, never hurts to check...

Re:Knowing Your Neighbours

[jamstar7]

Never mind what SETI are doing, the STI (Search for terrestrial intelligence) project havn't found much here on earth yet! ;)

Musta spent a year in Cleveland one weekend...

Re:Knowing Your Neighbours

[fahrbot-bot]

GP: 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.

P:That depends on how you are searching. Searching for your keys in a cluttered room with the lights off is going to be difficult...

Exactly, or if your keys are smarter than you and are actively hiding from you! One supposes this might be analogous to the Yeti being smarter than the Mountain Lion, or human.

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

[fullmetal55]

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. no intelligent life. Civilizations could rise and fall in the span of time you're specifying. especially the billion years. there could be many civilizations that have risen, explored the galaxy looking for life, died out, and vanished from the universe. There are so many assumptions necessary in this search.

Re:Knowing Your Neighbours

[osu-neko]

The flaw with all these searches is that it assumes that any nearby civilizations are exactly at the same level of development as humanity.

No it doesn't. An experiment to detect radio emissions from nearby civilizations assumes only that there's a possibility that there might be a nearby civilization that uses radio waves for some purpose. It does not in any way assume that all civilizations do.

Calling an experiment flawed because it can't detect what it isn't even looking for is like calling an MRI flawed because it didn't detect your athlete's foot. My cable box doesn't pick up short-wave radio, either. Gosh, everything is flawed...

Re:Knowing Your Neighbours

[meta-monkey]

Unfortunately quantum entaglement cannot be used to transmit information. From the receiver's point of view, there's no difference between a state resulting from the sender's measurement and the state resulting from his own. See No Communication Theorem.

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

[trianglman]

Basically, I think you have the right premise, but to adjust Sagan's quote to be a bit more accurate - "Absence of evidence is not evidence."

Re:Knowing Your Neighbours

[egyptiankarim]

Physical contact is irrelevant, really. As soon as broadcasts can be produced to potentially find any ETs, the possibility for communication opens up, no? And isn't that really the true purpose of all this anyway? To communicate. I mean, sure, meeting an alien might be cool, but what's there to gain from that that can't be gained from a cool high-powered radio network set-up?

Re:Knowing Your Neighbours

[funfail]

From the summary:

the MWA-LFD could detect Earth-like radio signals from a distance of up to 30 light-years

Re:Knowing Your Neighbours

[radtea]

Regardless, you are attempting a negative proof or proof of impossibility. This is a logical fallacy.

I always laugh when I hear this. Back in the day when I was part of the search for physics beyond the standard model, all we did, all day, year in and year out for decades, was prove negatives.

Protons do not decay in less that some large number of years.

The 17 keV neutrino does not exist.

There are no further generations of quarks beyond the known three.

And so on ad infinitum, ad nauseum.

It is, using certain limited forms of deductive logic, impossible to prove with deductive certainty some veryt narrowly construed types of "negative" proposition.

It is, using the much broader toolkit of empirical and theoretical science, perfectly possible to prove a very wide range of negative propositions, and we do this every day.

Even within the limits of the sort of mathematical logic used in theoretical physics we prove negatives routinely. In the late 80's and early 90's there was some interest in nonthermal plasmas and self-colliding beams for 3He or p-B fusion. Then some grad student published a proof that no such system could have a plasma beta above some critical limit, which proved that you would never be able to achieve breakeven.

This kind of thing happens all the time. The claim that "it is logically impossible to prove a negative" is either false or uninteresting. It simply does not address the kind logic and the kind of negatives that scientists routinely use.

Re:Knowing Your Neighbours

[Mr Z]

Quantum entanglement certainly can't be used to transmit information faster than the speed of light. I was thinking along the lines of quantum encryption.

Re:Knowing Your Neighbours

[div_2n]

I missed one word in the sentence. It does not invalidate what I said in general. I have no confusion with evidence. The definition of "evidence" I am using is the one you can find in the dictionary here.

As in evidence is used to prove or disprove. But as I said, a negative proof is a logical fallacy. A negative proof and disproving something shouldn't be confused as the same thing, though.

Re:Knowing Your Neighbours

[Oktober Sunset]

would be a rather dawn out conversation.

Earth: Yo ET, This is Earth calling hows it hanging? You wana exchange some information, learn about human culture n we learn about urs 30 years later ET: Yo Earth, sure, sounds good here's a data transmission all about us, tell me all about human culture. another 30 years later Earth: Umm, yea, a few things have changed since the last transmission, probably best to forget about human culture, there ain't noone but us giant mutant cockroach thingys over here.

Re:Knowing Your Neighbours

[vhogemann]

AFAIK, Artificial RF sources can be identified because they use a very narrow band of the spectrum, in contrast to natural sources that are much more spread.

So, even if we can't decode the signal, we'll know that it might be from an artificial source.

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

[Minimum_Wage]

True enough. If I had to re-write my post I think I'd phrase it differently. It's not a flaw, just an assumption that (IMHO) depends on a lot of things occuring at the same pace on several planets within several light years. Not impossible, but not too probable either.

Re:Knowing Your Neighbours

[GNUThomson]

Quantum entanglement for long-distance? Didn't you heard about subspace communication? No wonder that you've dropped off from starfleet academy.

Re:Knowing Your Neighbours

[ACMENEWSLLC]

>>The flaw with all these searches is that it assumes that any nearby civilizations are exactly at the same level of development as humanity.

Exactly what I was thinking. My home phone uses frequency hopping and encryption. The signal it sends out is said to sound like the noise on those frequencies (the stars.)

Now I don't expect the power of my phone to be enough to reach another solar system, however wouldn't one imagine that most civilizations would quickly advance to use signals that would be protected from detection and remote capture?

So what we are looking for is either a civilization that hasn't advanced farther than our own, or one which is also looking for us by sending out a detectable signal.

Also bare in mind that the signals we are getting today could be produced hundreds or more years ago. It takes time for these signals to reach us.

Re:Knowing Your Neighbours

[GreggBz]

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).

Assuming their atmosphere and it's weather patterns are similar to Earth's. Assuming they are not aquatic, or live in liquid methane. Assuming their sensory capacity is similar to our own, maybe they can perceive gravity waves or something. Assuming they have the resources and materials to construct electronics that give them the capacity to use a radar type system. Assuming they don't have an incredible sense of smell and have not developed all their communications technology based on that paradigm.

We can't even communicate predictably with Humpback Whales. And, despite the best efforts of lots of creative people, most of the made up aliens that I see in science fiction are less interesting than a Platypus. So not to sound pessimistic, but making any reasonable predictions about a civilization that developed on another world is kind of silly. There are to many unknowns.

Re:Knowing Your Neighbours

[Hyperspite]

I believe the difference is the size of the search space and the potential benefits of discovery. IE who really cares about a Yeti vs knowing that there is other intelligent life in the universe?

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

[myowntrueself]

Carl Sagan quotes aren't always great when it comes to extraterrestrials...

I'll never forget his "Its impossible that extraterrestrials might one day visit the Earth because of the amount of time that an interstellar journey would take".

Re:Knowing Your Neighbours

[snarkth]

I'd like to note that any civ with a well-developed space program is likely to be using more numerous and more powerful radars than we are, spread thruout their solar system, as well. Since at least some of those radars would be longrange and focused "outward" that would increase our chances of detecting them.

  snarkth

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

[myowntrueself]

The claim that "it is logically impossible to prove a negative" is either false or uninteresting.

I think people got confused by propositional vs predicate logic with quantifiers.

eg: For all x there exists some y such that P(x,y)

There does not exist an x such that for any y P(x,y) where y is a member of an infinite set.

Its easy to see that over an infinite set (or as good as infinite, for what its worth), its not possible to prove such a statement because you would have to take your x and go through each instance of y and check P(x,y).

Such a task would never be completed, therefore it *is* logically impossible to prove (within predicate logic). Propositional logic is another thing again.

Eg, Newton and Freud use exactly the same formula (under predicate logic) and neither are disprovable;

'all dreams are neurotic symptoms'
'every action has an equal and opposite reaction'.

Re:Knowing Your Neighbours

[getmerexkramer]

Hey don't laugh, back in my day we communicated with interplanetary space craft using semaphore... And yes, of course we liked it.

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

[Original Replica]

Unless of course they stopped useing radar, because there is no good way to stop those waves once you send them out, and so radar would be broadcasting your position to any and all potential enemies, just begging to be invaded.

Re:Knowing Your Neighbours

[digitalchinky]

Back when I was working for one of the 3 letter agencies swinging rather large satellite dishes around the sky, I can safely say from long experience that it's pretty damn hard at times to find a bird up in the clark belt when you know its location fairly precisely. Typical station keeping will have them moving about their allocated box by a few tens of kilometers which can often mean the difference between a strong lock on the telemetry beacon, or none at all - depending upon the size of the dish.

I think the odds are mostly against us on many fronts, though that doesn't mean we shouldn't try.

Re:Knowing Your Neighbours

[Roman Coder]

From http://en.wikipedia.org/wiki/Coelacanth/...

Ironically, Malan was a staunch creationist; startled by the sight of the ancient creature, he exclaimed, "Why it's ugly! Is this where we come from?"

Re:Knowing Your Neighbours

[silentounce]

Unless of course they stopped useing radar, because there is no good way to stop those waves once you send them out, and so radar would be broadcasting your position to any and all potential enemies, just begging to be invaded. You assume that aliens wear tin foil hats.

Re:Knowing Your Neighbours

[shanen]

Typical seti@home level thinking. What the article says is not that we could not detect them, but only that we could not detect them if they were making no attempt to be detected and were only 'leaking' the same amount and kind of electromagnetic radiation that we've emitted in the extremely short time since we started doing it.

Think of it differently. Assume that there was any case of a civilization that had benefited from radio contact with a different civilization. If such a case existed, it would seem to be natural for them to try to return the favor by contacting other civilizations. If a relatively small power plant (and we already have thousands of really large power plants) were devoted to such a project, it could produce a beacon that would be easily detectable throughout our galaxy with our present technology. (Okay, you need to assume it runs for a relatively long time to reach the entire galaxy.)

So what does it mean that we have not detected any such radio beacon? Well, evidently there isn't any beacon to be detected. No civilizations? No benefit received? Or some reason to keep quiet?

Fermi was no fool. His paradox is worth serious consideration.

Re:Knowing Your Neighbours

[dastardly_villain]

Do we assume the same thing for aliens? Reasonable thinking, and it may be entirely accurate if ever put to test but I choose to think differently. To assume so would be to assume that alien lifeforms will display the same characteristics of life right here at home. Furthermore, who's to say we even really understand 'life' enough to detect it when we do find it? Maybe we aren't advanced enough to receive messages being sent to us. The fact of the matter is whatever we find (or have found) in space could display none of the characteristics of life as we know it....therefore it would be discounted and the search would continue unabated. Someoneelse in this thread likened this situation to a man searching for lost keys under a streetlamp because that's where he can see. Meanwhile the man's keys are really obscured by darkness not very far outside his field of vision... This person has some chance of stumbling upon his keys, but his chances are greatly diminished by the fact that he's searching in the entirely wrong place. If we only look for one specific TYPE of life that we can compare to life on earth (cellular and carbon based), we are effectively turning towards that street lamp, while the darkness may really hold the key. That said, there's the argument that we can only search for what we understand...or to understand things we find that make us question what we thought we understood. This is what we call science.

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.

Re:Knowing Your Neighbours

[Chris Burke]

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.

I highly doubt that the funding for this project would significantly impact research into our own planet to the extent that there is a will to learn about it, and I also highly doubt that the researchers for either endeavor would be the same people. So I see no reason we can't do both.

Re:Knowing Your Neighbours

[emilper]

... we can't communicate predictably and effectively with the guys across the pond ... it's only in B-rated films that the hero plugs in the big computer, a couple of lights blink and, presto, he talks with the 3-eyed alien.

Re:Knowing Your Neighbours

[instarx]

Earth: Yo ET, This is Earth calling hows it hanging? You wana exchange some information, learn about human culture n we learn about urs 30 years later ET: Yo Earth, sure, sounds good here's a data transmission all about us, tell me all about human culture. another 30 years later Earth: Umm, yea, a few things have changed since the last transmission, probably best to forget about human culture, there ain't noone but us giant mutant cockroach thingys over here.

Not the way it would work at all. It would be stupid to send a message and then wait 60 years for a reply. Both civilizatinos would start sending streams of information without feedback. The receiving civilization would pick and chose what is interesting, inserting a query for more information about a particular topic into their data stream. That insures that specific questions get answered after a long wait, but it may have been answered in the meantime in the regular data steam.

It gets really interesting when you find more than one civilization. As well as sending your data stream to civilization B you also forward civilization C's data stream as well. They do the same and before you know it you have a giant interglactic internet with constantly flowing data streams that you can pick useful information out of as it goes past. Sort of a giant ethernet ring.

Re:Knowing Your Neighbours

[snarkth]

Unless they found some more advanced form of mass detection at large distances, it'd be pretty hard to have a stellar system faring civilization without radar (or lidar). Think about it.

  If they've found some more advanced way to detect and track masses over long distances, they won't likely be communicating in any "band" we know how to detect - not yet, anyway.

  But if they are using radar or laser communications across solar system size distances, those emissions would be powerful enough to be picked up by the array that's talked about in the TFA. Within maybe a score light years.

  Think of the current SETI projects as a narrowband filter on the possibilities of communication. As far as detecting interstellar communications goes, we're just barely at the level of Marconi.

  snarkth

Re:Knowing Your Neighbours

[cbacba]

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

And it won't in the future. Scanning earth just over a century ago would have resulted in nothing. And how many years from now will it be before radio and tv are primarily fiber optics or low power highly directed satellite tv/radio beams pointed back to earth? My guess is very few decades will pass before we become a much quieter place in the radio spectrum again. Then again, there may be some mechanism that replaces radio altogether when it comes to off world activities, something that utilzes one or more of the quantum wierdnesses we seem to have observed (or have yet to observe) that could remove the long delays present in long distance EM waves.

Then again, what are the real odds that even if there is highly evolved advanced life out there, that it is even intellegent. It's curious that on this mudball, man is the only species that developed technological intellegence and did it over a very short time, despite being a very young species compared to many, if not most others. Even after being around munching salad and on each other, the dinosaurs failed to develop any intellegence, only bigger claws and bigger teeth.

Re:Knowing Your Neighbours

[bill_mcgonigle]

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.

SETI is only looking for intentional signals meant for us to find. There are estimates out there on what it would take to build a generator for such a signal and it's not beyond our capability, but probably beyond our means.

SETI also bets on the psychology of aliens wanting to do this. Personally, I think they'd rather wait for us to be unafraid to broadcast a "here we are" signal so they know they've got a mature civilization to deal with. We may have done this once or twice, but most folks are more afraid of the aliens coming and eating us than wanting to meet new galactic neighbors.

Re:Knowing Your Neighbours

[l0b0]

[...] SETI@home hasn't found any signal yet, even after years of listening.

An article about Three SETI Myths should put this statement into perspective. From the article: 'In the first twenty years of "listening," twenty-three targeted radio SETI projects conducted a total of ninety days of searching.'

Re:Knowing Your Neighbours

[Oktober Sunset]

Still doesn't solve the embarrassing situation for the giant cockroaches.

"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...

Re:"Earth-like" civilizations?

[Dachannien]

I don't know about you, but I make a concerted effort not to watch any version.

Re:"Earth-like" civilizations?

[CaffeineAddict2001]

Our analysis suggests the large male on the left is the leader of earth. Directly to the right is his attractive wife who we are unable to derive any logical semantic patterns from. The other two females seem to have been exposed to a strong gravitational field for quite some time and appear to resent the leader.

It is believed that the new leader came to power after a military coup with a dark hued shape-shifter.

Re:"Earth-like" civilizations?

[meta-monkey]

Oh, man! Then we can watch the epic battle between Space Donald Trump and Space Rosie all over again!

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?

[CastrTroy]

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.

Re:any physicists out there?

[interiot]

http://en.wikipedia.org/wiki/Superluminal_communic ation

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?

[UbuntuDupe]

This would be a good opportunity for someone to explain why it's impossible to fabricate a material with a high enough incompressibility that its local speed of sound exceeds that of light. That is, specifically what fundamental principle would you have to violate in the process.

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?

[Nasarius]

Sounds are transmitted by the vibration of particles. Any particle with mass moves at less than c, so it's impossible for the "speed of sound" to be greater than c.

Re:any physicists out there?

[meringuoid]

Could you list any of the current areas of research which may some day allow for information transmission faster than c?

Prayer?

Re:any physicists out there?

[UbuntuDupe]

The question is about the transmission of information, not particles. And "speed of sound" is not an expression I just made up.

Re:any physicists out there?

[Nasarius]

Well, you asked a specific question. And I'm not sure why I put the speed of sound in quotes, though it does seem like an arbitrary concept if you look at it from the atomic level.

Re:any physicists out there?

[UbuntuDupe]

"Speed of sound" simply refers to the speed of propagation of compression waves. The point was this: if I had a completely "incompressible" row of particles, and I push on one end, I could (again, in theory) cause them all to move as a mass. So even though each particle moved at the speed of the push, the information that it was pushed, traveled instantly. The fact that the particles moved slowly doesn't have anything to do with the information transmission.

Re:any physicists out there?

[Solitonic]

It is indeed possible for the speed of sound to exceed that of light, not by increasing the incompressibility of the material (which increases the speed of sound) but by increasing the index of refraction (which decreases the speed that light travels in that medium).

A few years back, some Harvard physicists grabbed headlines by slowing down light in a Bose-Einstein condensate to 38 mph! More recently, just a couple of weeks ago, Japanese scientists fabricated nanocavities in solid state which slowed light passing through them to 5.8 km/sec.

...what fundamental principle would you have to violate...?

Incompressibility of a material is mediated by the electromagnetic force arising from the charges inside and between the atoms comprising a material. As such there is a fundamental limit to the magnitude of the incompressibility. You can always push those electrons closer together (until they disappear on you, creating a shower of new particles).

Sound waves are ultimately constituted by moving particles, and according to relativity it is not possible for a particle (or even information!) to move faster than c=299792458 m/s (not to be confused with "the speed of light" which is only equal to c in vacuo). This is unless those particles are (hypothetical) tachyons, in which case they can never move slower than c (but even then, they cannot transmit information faster than c.)

Even inside a neutron star, the Pauli exclusion principle is insufficient to prevent the neutrons from compressing and collapsing into a black hole.

Re:any physicists out there?

[missing000]

The grandparent is correct. The speed of sound is variable and is determined by the mater the sound is traveling through (really just bumping atoms together).

Any solid is really just widely separated atoms linked together by the strong force, and bumping one side of said solid causes a rather quick domino routine which is replicated on the other side at some significantly small fraction of c.

Re:any physicists out there?

[missing000]

If you had said incompressible row of particles they would be a singularity and thus take up no space.

Re:any physicists out there?

[crc32]

Could it stem from the fact that there are no truly incompressible particles? All particles are primarily empty space, so some degree of compression is given. Just an uninformed stab...

Re:any physicists out there?

[Solitonic]

What you are describing is a truly rigid body, and unfortunately there is no such thing in nature. It would require instantaneous action at a distance. This is also why Newtonian physics ultimately fails.

There is always a finite propagation time for the the electric field of the moved charge of the first particle to reach and repel the next particle in the row, etc. These interactions are mediated by (virtual) photons (ie light).

Re:any physicists out there?

[UbuntuDupe]

Incompressibility of a material is mediated by the electromagnetic force arising from the charges inside and between the atoms comprising a material. As such there is a fundamental limit to the magnitude of the incompressibility. You can always push those electrons closer together (until they disappear on you, creating a shower of new particles).

Okay, but I don't see how that answers my question. Why, specifically, can't the level of compressibility fall to such a level fall to that which allows compression waves to propogate faster than light (I know, I know, "light would travel in a vacuum")? Remember, at no point would a particle have to move faster than c.

Re:any physicists out there?

[Solitonic]

There has been a speculative proposal by Miguel Alcubierre, in the context of General Relativity, that takes advantage of an imagined negative energy density in some region of spacetime to produce a metric (a special kind of curvature of the spacetime) that allows for superluminal transport of matter. That is, a warp drive.

The good news here is that there is a known phenomenon of quantum field theory (the Casimir effect) that causes the region in between two highly polished metal plates that are extremely close together to develop a measurable negative energy density. (Basically the plates filter out the zero-point energy of long-wavelength electromagnetic quantum fluctuations of the vacuum that would otherwise be present, but cannot fit between the plates.) The bad news is that the effect is utterly negligible in strength.

Re:any physicists out there?

[dr_dank]

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.

I've never understood this part of quantum mechanics. The papers in your example didn't magically change color because they weren't being observed. One was always black and one was always white. The uncertainty only comes into play as to which person gets which color slip of paper.

By this logic, my dog can recite the complete works of shakespeare in esparanto.... unless somebody is in listening distance.

Re:any physicists out there?

[WhiplashII]

OK, how about this (well, some variation on this):

We take a billion envelopes, each with their "gray" paper and send them out. Then, each second we take an envelope and send it through a grating (um, the postage equivalent of a grating), and observe the result. If the paper is black or white, we see no difraction pattern. If the paper was "gray", we eventually see a diffraction pattern in the ouput. We have then sent a message FTL - that the other party has collapsed the wave function of all of his remaining particles.

In the QM I know, you can tell if an electron's wave function has collapsed if you send it through a grating (though this is a destructive test). Why can't something like that work? Isn't there an equivalent to a diffraction grating for electron spin?

Re:any physicists out there?

[inviolet]

I've never understood this part of quantum mechanics. The papers in your example didn't magically change color because they weren't being observed. One was always black and one was always white.

They didn't change color... because they didn't have a color at all.

This is indeed the weird thing about our universe: things aren't specific until they need to be, when somebody is observing them. When nobody is looking, they revert to approximations.

It's a compelling clue that we are actually living inside a simulation. Approximations are the universe's way of conserving CPU power.

Re:any physicists out there?

[GospelHead821]

It is for this reason that the analogy is just an analogy. It is descriptive of the phenomenon but it does not simulate it perfectly. When thinking about slips of paper in envelopes, you're right, the slip that your brother receives is determined the moment you drop the envelope in the mailbox. I could not begin to explain why (I only vaguely understand it, myself) but when thinking about quantum-scale particles, the particle actually is neither black nor white until it is observed, which collapses the state of the particle and the other particle(s) to which it is entangled.

Re:any physicists out there?

[physicsnick]

A ship using an Alcubierre warp drive is causally disconnected from the bubble itself. In other words, once you start going, you can't stop. You need some external device to stop you. So you'd need to move said external device to your destination beforehand using subluminal travel, and then you'd need to aim your ship towards it and hope you don't go off course while in warp drive; the stopping device can't be adjusted to catch you because they can't even see you coming.

It also requires astronomical amounts of energy, like the energy a star burns in its entire lifetime just to form the bubble. The Alcubierre drive is pretty much just a mathematical curiosity at this point.

Re:any physicists out there?

[Solitonic]

What are compression waves? They are merely trillions of particles (atoms/molecules) moving in concert due to their interactions with other particles up and down stream.

Reduce this down to the atomic scale and think about it like this: atom #1 propagates through space at speed v (less than c) until it approaches atom #2. Atoms #1 and #2 then interact. In the context of quantum field theory, this means that one or more virtual photons are exchanged between the charges (electrons and protons) in atom #1 and atom #2. This interaction takes time (which is not negligible) for those photons to propagate. Through this interaction some momentum is transferred from atom #1 to atom #2. Now atom #2 has to propagate, and so on...

So what you said is not true. For compression waves to move faster than c, the constituent atoms (and virtual photons) would also have to.

Re:any physicists out there?

[LordKronos]

When nobody is looking, they revert to approximations.

If NOBODY is looking, then how does anyone know they revert to approximations?

Re:any physicists out there?

[Lord Ender]

No, I was asking about reality. So I am going for things like extreme gravity, singularities, maybe even string theory interdimensionality. And no, it wasn't a joke question. The smartass who modded it funny has an unsophisticated grasp on physics.

Re:any physicists out there?

[radtea]

When nobody is looking, they revert to approximations.

Not quite: when nobody can be looking, they become undefined (not an approximation, which is defined but imprecise).

Since you mentioned simulation, think of it in these terms: an unobservable (not unobserved!) aspect of reality is represented by a null pointer in the view (the universe of space and time). When the simulation detects that an observation can be made by dint of strong coupling to a system with many degrees of freedom that will result in decoherence, the null pointer is assigned and points to a value from the model (whatever lies behind the quantum veil.)

Because the model is no respecter of space or time or any of the rules of the view, this is quite different from the pointer pointing to a value all along that we just don't happen to know about. The value "exists" in some fairly ethereal sense (we can assign a probability distribution to the values the model might assign to it) but the model uses unknowable rules to do the actual concrete assignment, which violate the constraints of the view (i.e. violate Bell's Inequalities).

Re:any physicists out there?

[MaWeiTao]

This is the best explanation I've seen to date for why quantum entanglement doesn't work as a means of communication.

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.

Re:any physicists out there?

[ajpr]

What happens if the slip of paper is white on the other side? Say the brother then flips over the black slip of paper and it's white. Can he then infer that your slip of paper also flipped over instantly?

(I know you got a lot of replies but please answer this!)

Re:any physicists out there?

[Orange Crush]

One was always black and one was always white.

IANAP, but the way I understand it is that particles behave as waves until observation causes the waveform to collapse into a particle. Our pieces of paper will "act" gray (as waveforms of their black-or-white color probability) until the moment the envelope is opened.

Re:any physicists out there?

[Lord Ender]

In the QM I know, you can tell if an electron's wave function has collapsed if you send it through a grating

If that is true, then it is possible to transmit information in binary (0=not collapsed, 1=collapsed) form without the lightspeed limitation.

Which makes me suspect you misunderstand something.

Re:any physicists out there?

[ajpr]

Thank you very much for that. I've wondered about that for a long time and now can put it to rest :]

Re:any physicists out there?

[arevos]

I've never understood this part of quantum mechanics. The papers in your example didn't magically change color because they weren't being observed. One was always black and one was always white. The uncertainty only comes into play as to which person gets which color slip of paper.

Particles frequently behave contrary to what common sense would suggest. Experiments tend to show that when a particle is unobserved, it exists in all possible states, whilst when it is observed, it collapses back into one.

Particles can also be entangled with one another, such that, for example, one particle is always the opposite of another. Perhaps it's not unreasonable to consider observation as merely a form of entanglement.

By this logic, my dog can recite the complete works of shakespeare in esparanto.... unless somebody is in listening distance.

More accurately, the dog would be in all possible states, until observed, much like a famous cat.

Re:any physicists out there?

[WhiplashII]

Which makes me suspect you misunderstand something.

Yeah, the old if it would be that nice it doesn't match reality axiom. But why does it fail?

Re:any physicists out there?

[Belial6]

Which means that we should as soon as possible, start entangling particles inside of a quantum observed/not-observed telegraph machine. Then send them out in every direction. This would, given time, create a galactic telegraph system that would work outside the laws of physics that limit the transmission of information to the speed of light.

Re:any physicists out there?

[Tim C]

Because theory and experiment both demand it; the theories only work, and the experiments only make sense, if that's what's happening.

It goes against common sense, but then our common sense is born of our experiences in a macroscopic, Newtonian world; that's why they break down in microscopic and/or relativistic frames. We simply don't have the experience of dealing with them.

Re:any physicists out there?

[Lord Ender]

My QM in college went about as far as "calculate the frequency of a bowling ball of mass m." I had never heard of the "grating test" for determining if a quantum state is collapsed. Do you have a reference on this? My understanding was that light speed is the limit on the speed of information transfer in the universe.

I would be willing to bring this question before some contacts I still have at school if you could point me to a reference to the grating test.

Re:any physicists out there?

[arevos]

Which means that we should as soon as possible, start entangling particles inside of a quantum observed/not-observed telegraph machine. Then send them out in every direction. This would, given time, create a galactic telegraph system that would work outside the laws of physics that limit the transmission of information to the speed of light.

There are a two problems with that idea:

1. The telegraph machines would only have a finite number of entangled particles, and once observed, they resolve themselves to a fixed state and cannot be used again.
2. When an entangled particle is observed, it randomly collapses into one state or the other, so no information is actually transferred at the speed of light. Perhaps if it were possible to influence the state of the particle by observing it in a certain way, but we have yet to discover any effect like that, and it may even be quite impossible.

No one has yet to succeed in sending information faster than light. Quantum entanglement is an alluring possibility that suggests it may be possible, but it could also be a red herring.

Re:any physicists out there?

[WhiplashII]

My understanding of QM comes from a book with Schrodinger's cat on the cover, written towards the common man as it were. It said that pratically every problem in quantum mechanics can be rewritten as a variation on the classic experiment: you run electrons through a diffraction grating (or 2 slots, which behave as a diffraction grating). As you would expect, you see the wave like behaviour of the electrons and so the time-integrated flux of electrons varies in a pretty pattern. You then decrease the electron flux to where only one electron goes through at a time - but the pattern stays there! Even though there are not any other electrons to cause the inteference pattern! Trying to get to the bottom of this, you put a sensor that detects the electrons as they pass one of the slots - but then the pattern instantly goes away.

So to me, that means that you can use a diffraction grating as a sort of quantum state collapse detector.

Reading on Wikipedia, it seems that they key to not allowing communication is to not allow duplication of quantum state - if that is true (which seems unlikely, given the following), then there is a simple answer. Entangle one quadrillion electrons. At a later time, the receiving person starts checking Z spin or whatever. He will get random directions until the transmitting person (in one fell swoop) checks the spin of all quadrillion electrons. Now the spin direction shows a bias, which can be detected (this is streching my understanding, but I'm not sure where I am wrong here).

Just curious as to the exact nature of the limitation.

Re:any physicists out there?

[WhiplashII]

I found the book: In Search of Schrodinger's Cat - Quantam Physics And Reality, by John Gribbin. I do rather recommend it, if your interested in such things - it is very readable.

The first part of the experiment is very humorously portrayed here.

Ah, here is the description I needed - it describes how two slits can be used to check for collapsed states, though you need to read between the lines a little.

Re:any physicists out there?

[snooo53]

I'll be an armchair physicist here and say it seems like that would certainly be an experiment that could be set up in theory. Entangle two streams of particles, send them on their separate way towards two diffraction gratings. Start up the slit detector behind grating 1 to cause the particles to have a classic particle distribution, and see if the same happens at grating 2 with no detector.

The problem with this is I think the diffraction grating would potentially cause decoherence, making the whole experiment worthless.

Re:any physicists out there?

[snooo53]

Your description of the double slit phenomena is really good. Wikipedia has a good pictoral reference too.

Double-slit_experiment

I think the problem with your experimental setup is like many others, is that yeah, the sender could in theory check for the bias in spin of all quadrillion but would still have no influence over the random outcome. So the observers would essentially see the same information, but it's all the same *random* information. Of course that makes me wonder too about a material like a bose-einstein condensate... aren't all those particles in the same state?

One other thing I am curious about is if these state measurements have to be taken simultaneously... or could one wait a half hour (assuming the nothing interfered with their particle) before measuring it? And what is simultaneous anyway when you look at the universe from a relative viewpoint.... these type of things make my head spin!

Re:any physicists out there?

[YttriumOxide]

I disagree... and yes, I'll probably get flamed for it.

I really think the entire concept of approximations and randomness is just flawed. Isn't it entirely possible, and in fact more likely, that there are simply other factors involved that we have no way of currently measuring or understanding?

For example, a quantum theory can determine something has a 60:40 chance of two possible outcomes and repeated experiments can then confirm this. Does this mean the universe is really acting in a "random" fashion, or is it just that there's a variable we're NOT measuring or even conceiving that if we DID know about, we could precisely determine the result?

Re:any physicists out there?

[LordKronos]

I disagree... and yes, I'll probably get flamed for it.

I really think the entire concept of approximations and randomness is just flawed

Well, you certainly won't get flamed by me. I agree with you, which is why I proposed the question. The whole idea of "randomness when you aren't looking" seems to me to be a bunch of voodoo magic, and compared to the theory that we just don't know all the details, the randomness theory doesn't seem to pass Occam's Razor for me.

The whole thing kind of reminds me of the early sensorimotor stage of a child's cognitive development. Before they grasp the concept of object permanence, they don't seem to understand that things still exist even when they can't see them. Gone from view, gone from existence. It seems silly to revert to that type of logic.

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?

Re:Interesting idea - but same old problem

[toddhisattva]

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?

Because they, too, have found smoke signals to be inadequate.

Radio waves are a natural phenomenon, which can be controlled by technology. They aren't specific to humans - stars and gas and lots of stuff emit radio.

Also, "radio" is just part of the EM spectrum, and not even a specific part. From a few Hertz to, well what's the border between microwave and infrared? We Earthers say "about a terahertz." I suspect the border is defined by your equipment ;-)

Add to it that amplitude modulation is such a simple, obvious way of transmitting information, and the clearest, easiest form of AM is CW (continuous wave suitable for Morse code, not country-western).

Some of our FM schemes are probably human-specific, like stereo FM with the stereo sep information carried above the frequency of human hearing (a 38kHz wave for a Nyquist of 19kHz IIRC), and may differ from country to country. But AM and especially CW are easy and obvious, you might even say "natural," things to do with a radio wave.

(Our TV schemes are even more human-adapted than FM.)

Radio is as natural a way of communicating in the universe as hollering is in Earth's atmosphere. Think of the wide variety of hollerin' life we have here, from cicadas to Amy Lee.

Re:Interesting idea - but same old problem

[kalirion]

That's a good point. We're looking for a civilization X light years away that was at pretty much exactly our technological level X years ago. The only thing that could extend the window is if they continue beaming high power radio waves into space for the sole person of indicating their existence to aliens.....

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!

Re:Impossible!

[Fx.Dr]

Does this mean we'll all eventually owe someone major $$$ for listening in on cosmic background radiation?? Pfffft, thanks for nothing, science!

Hmm.

[JavaLord]

30 light-years, which would encompass approximately 1,000 stars.

I guess it depends on how abundant life is, but this doesn't seem like it is very far/much in the grand scheme of things.

Even if an advanced civilization is out there, what makes us think they would be using radio? It's possible, but I could see FM radio being obsolete 100 years from now. I know the article mentions radar too, but it seems like a lot to assume...that advance life evolved, and is around the same time in techonological progress than we are and uses the same type of technology. 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? :)

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.

Re:Hmm.

[homer_ca]

The real longshot is that artificial, high power radio transmissions have only existed on Earth for 70 years, and who knows for how much longer? Compare that to the 5000 years of civilization, 200,000 years of modern humans, and the 5 billion years that the solar system has existed.

Re:Hmm.

[jagspecx]

aren't the odds of two technically advanced civilizations being around at the same time...umm astronomical?

Aren't the odds of one technically advanced civilization being around astronomical?

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.

Re:Hmm.

[Chode2235]

Your argument assumes that there is no correlation in evolution between us, nature, and our tools. Humanities ability to develop tools, and use them has greatly contributed to our physical evolution. So if a species is physically identicle, then it assumes that we have similar tools and technologies. We evolve due to environmental stimulus, including both the natural world and the ways that we collectively engage it.

Re:Hmm.

[mpthompson]

A race biologically identical to ours in any given solar system may be as physically evolved as we are, but notably superior technologically having not suffered the loss of their own Library of Alexandria, or a complete lack of their own Dark Ages.

I have always wondered what our civilization would look like today if the Roman empire had developed 18th and 19th century level steam technology 1800 years earlier. I presume it would have lead to a cascade of scientific discovery and technology development around the harnessing energy that had to wait until the Dark Ages were over.

Re:Hmm.

[Chris Burke]

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.

Unfortunately the scales of "ages" in an astrological or geological sense are so much greater than those of human development that even if this perspective is true then it could still be very unlikely that our high-tech era overlaps appropriately with any other life forms'. A few extra million years in the formation of a planetary system is in the noise for those systems, but could guarantee that we'll be long gone before another sentient life form evolves on another planet (or vice versa, they may have come and gone long ago).

Re:Hmm.

[Cedric Tsui]

So, a civilization that maintained a golden age for 2000 years? I wonder if that is possible.

As for the quote. Sol is a third generation star. And there are huge variations between the ages of such stars. So it is possible for an alien race to be several billion years ahead in the physical evolution race as well. Billion. Kinda scary hun?

Re:Hmm.

[YttriumOxide]

No, the odds are exactly 100%... we exist.

Re:Hmm.

[LordSnooty]

The independent 'invention' of echolocation by bats and humans is evidence that life-forms could arrive at the same point technologically without influence from each other. The only caveat would be that the two inventions took place in the same environment.

Re:Hmm.

[WilliamSChips]

It will be beamed directly into your head.

Re:Hmm.

[jagspecx]

Yesterday I had someone in the corporate communications (brand) department at work try to tell me (a web developer) that Xoops (the CMS system) is the engine that PHP runs on.

*sigh*

Maybe I'm being too hard on us, but I think we have a little way to go... ;)

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.

Re:Obligatory

[zobier]

...as a .net geek...

Um, I think you're on the wrong forum.

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

[mike2R]

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.

Agree, but TFA mentions some future equipment that would be able to find signals within a radius of 300 light years - around 100 million stars. I'd say that would be a big enough sample size to draw some tentative conclusions - an absence of any signals at all would seem unlikely if intelligent life is as dense as most of us (I'm guessing) hope.

Anyway there's always the hope that we'll get lucky (or that the universe teems with intelligent life), and we'll find signals 30 light years away. I'm actually quite excited about this - it is possible we will shortly find proof of life on other planets, which would be pretty momentous.

Re:Window of opportunity

[pilkul]

Sentient life, which is a far bigger deal than just life. I'm not that excited about the question of whether there are primitive bacteria on Mars, personally.

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.

Re:Window of opportunity

[buzzzz]

You are correct. However, the facts, that life can survive in an alien planet and/or that lifeforms can be seeded across space, in themselves make it more likely that there might be life somewhere else in the universe.

The possibility that life on alien planets may have common origin is interesting in it's own way beyond the possibility that life may exist. It would be fascinating to even imagine the possibility that humans (or life as on earth) may exist on that distant start...

The bottom line remains that discovery of any life on Mars would be a significant victory for those who search for alien life.

Re:Window of opportunity

[SamSim]

How long do "earth like" civilizations put out RF energy that is detectable from space?

1 to 1.3 million years.

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 ! ;)

No Hands

[wooferhound]

There are hundreds of highly intelligent animals on the Earth, There are only a few animals that have evolved with Hands in which to build a radio or TV. The majority of animals only have Legs and a mouth and sex organs.

Re:No Hands

[silentounce]

"Legs and a mouth and sex organs"

Who needs anything else?

Re:No Hands

[Saikik]

So we should send porn to outer space?

Re:No Hands

[slackmaster2000]

There are plenty of animals that are *surprisingly* intelligent, but only surprising to our ego.

The opposable thumb and the human brain did not come about in the same creature by chance. We developed as a whole by necessity (although some people have a hard time understanding this, and think that each piece must have been individually crafted). It would not make sense that a creature would exist with the same language/abstraction capabilities as a human, but with no means of communication or creation. I doubt that there is a race of intelligent creatures on some distant planet that we would be able to communicate with, but they unfortunately suffer from a lack of hands and thus can't build radios. While it's true that there are a lot of evolutionary variables to consider that would make an alien much different from a human, we're all exposed to the same natural laws. And really, what we're looking for here is some sign of "human compatible" creature - something that we can communicate with to some significant degree - and since we can't go look for intelligent or any type of life on distant planets, scanning for signals is our only option.

The real issue here is that just having a big brain and some hands does not necessitate the building of a television or radio. Perhaps we built televisions and radios because of the way we developed in our environment, and there are other means of communication that would be obvious had we developed in a different environment. It's almost kind of funny to think about the infinite number of ways that aliens could be different from us, but still think, "I wonder how many channels they get?"

The other real issue, and an even bigger one, is that this really seems to demonstrate our naive view of time. Thirty light years? A month to scan a system? It took us millions of years to finally come about, and during that time were mass extinctions, ice ages, etc - and eventually there *will* be more of these. Even if an alien race within 30 light years had used radio transmission for ten thousand years before dying out or advancing, the odds of us picking up on that tiny little window are tiny.

I certainly want to search for the existence of alien life, but am only in favor of projects like this because they stimulate creativity and even feelings of hope. Pointing a dish at the sky and hoping to hear that we're not alone is entirely human.

Re:No Hands

[mfrank]

Since you're on Slashdot, unless you have nimble legs, you'll probably want hands :)

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

[syrinx]

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.

Wasn't all that long ago that the scientific consensus was sure that light was a wave propagating through the luminiferous aether. I think it's pretty arrogant to think that the things we 'know' are even a small percentage of what there is out there to know.

The real question is whether we're going to get kickbanned for being n00bs.

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

[meringuoid]

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 . . .

Real-time conversation is unnecessary - and a bad idea with such a signal lag. Why fall silent while awaiting a reply? Build a massive signal laser. Put it on the roof of Google HQ. Send everything. Continuously.

Re:Not a big area

[nido]

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.

I read something recently that pointed out that our universe is only "regular" around the edges of normal human experience, and turns "exotic" at the extremes. That is, the regular rules go away at sub-atomic scales (quantum mechanics), speeds approaching the speed of light (relativity), etc.

We're trained, in the government schools, with a sort of 'ideological blinders', where classic materialism is installed as the universe's presumptive operating philosophy. Materialism keeps getting revised to deal with contradictions between theory and reality - atoms were originally viewed as billiard balls, and were the smallest possible unit of existence. A better operating philosophy would only require 'filling in the blanks', and new data would be entirely consistent with the old theory.

Our knowledge of how the universe's fundamental principles is vastly incomplete. We've little idea how gravity and electro-magnetism interact, for example. If we did, there wouldn't be a Pioneer Anomaly. The Pioneer spacecraft are not where they should be, based on the current understandings of the universe's physical principles. Perhaps dark matter and dark energy are throwing the probes off their predicted courses.

One of the twentieth century's most distinguished scientists and Nobel laureates, physicist Max Planck, observed that; 'A new scientific truth does not triumph by convincing its opponents and making them see the light, but rather because its opponents eventually die, and a new generation grows up that is familiar with it.

Re:Not a big area

[DarthVain]

Well if we do find the giant IRC server of the universe I think we should lurk for a long time. I don't want to be apart of the noob planet!

Re:Not a big area

[Penguinshit]

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

Re:Not a big area

[Orange Crush]

Do you not think it would be meaningful just to receive the message "hello"?

Oh, any response would be momentous. The issue is simply that round-trip signal time for 30+ly is 60+ years. Whoever sent the signals may very well be dead by the time a response comes (if one comes at all).

Re:Not a big area

[kabocox]

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.

"Hello" or recieving a set of introduction instructins isn't a conversation. We might have a species reaction to finding out that there are other intelligent species out there, but that isn't a conversation. Don't confuse the two. Here's an idea. What if most of the elder species don't broadcast or actively block communications with immature species just because some times we might over react, panic or immediately try to wage war against our new neighbors? Keeping silent may be a security measure.

Re:Not a big area

[Grishnakh]

What if most of the elder species don't broadcast or actively block communications with immature species just because some times we might over react, panic or immediately try to wage war against our new neighbors?

This is probably exactly the case. After all, we can see with all the religiosity here on earth that most people simply couldn't handle the idea of life on other planets, since that directly contradicts their religion, and mass panic would ensue, causing the total collapse of civilization. We're already having a hard enough time coming to grips with the idea that the earth is more than 6500 years old.

Re:Not a big area

[Johnny5000]

Real-time conversation is unnecessary - and a bad idea with such a signal lag. Why fall silent while awaiting a reply? Build a massive signal laser. Put it on the roof of Google HQ. Send everything. Continuously.

Imagine the receiving civilization is already in touch with other civilizations and interstellar communication is old hat to them.

Suddenly, they start getting a crapflood of "HALLO! THIS IS EARTH! HALLO! THIS IS EARTH! HALLO! THIS IS EARTH!" on every channel of communication on their planet. Continuously.

I think if they had the means, they'd probably squash us like bugs just to shut us up.

It would be worse than AOL + usenet.

Re:Not a big area

[SamSim]

Do you not think it would be meaningful just to receive the message "hello"?

Meaningful, yes, but let me paint a pessimistic picture for you. What if the ONLY signal we get is "hello"? What if FTL is impossible, and all we get is a random message that their equivalent of SETI beamed out to nearby stars just to show they were trying - just like us, in fact - and we get nothing else from them, ever? No messages, no ships, no magic technology... what if they just quit transmitting, like us, and live in solitude and eventually kill themselves before our reply message can arrive?

I believe there would be uproar and debate for centuries to come in many fields of science. But I believe that the political structure of the world would not change significantly after this news. The average man in the street looks up in the stars a little more often, but his day to day life is unaffected. The way we number our years would not be suddenly restarted. One year later there would still be trouble in the Middle East.

To quote Clarke, there are two possibilities. Either we are completely alone in the universe. Or we are not. In either case, the thought is staggering. But thanks to the experiences of reality we are totally used to the first possibility and thanks to science fiction we cannot fail to be underwhelmed if and when the second possibility becomes a reality.

I hate myself for saying all this, really, I want first contact to permanently unify the whole globe in a single moment, but be honest with yourself, is that at all likely?

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?

[Phil06]

Just look for planets that are burnt to a crisp with lots of CO2 in the atmosphere. Oh right, Venus

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:What does "Earth like" mean?

[mfrank]

Four billion years ago the earth was hit by a really big rock. This caused the moon to form and the earth to have a crust thin enough to allow plate tectonics, which comes in handy if you want a long-term way for CO2 emitted by volcanoes to get back underground. If that hadn't happened, Earth would be just like Venus. No need to blame Exxon.

Re:What are the odds

[LWATCDR]

I would say pretty high. Radio waves are a part of nature. We use them because they are the best solution for broadcast transmissions and for mobile communications.
The systems are simple and work well. Odds are pretty good that they would have many of the same needs as we do and they share the universe with us so the solutins could be very similar. After all how long have we used the wheel?

The Flipside

[blueZhift]

The flipside of this is that Earth-like civilizations within 30 light years are surely able to detect us now as well! Of course if they are like us, they don't have any way of getting here anytime soon, so we're safe for now. After all, if they could, they would try to invade and conquer us just like that, if not, then they aren't like us at all!

Mars Martians where not enough eh

[VEGETA_GT]

We already Killed ET's relatives on Mars Now thats not enough, now we must find ET himself as we have some science experiments to do on him

Mmm...

[SuperStretchy]

Makes me think of Spore some more.

Good.

[FlyingSquidStudios]

The current Earth shows are kind of dull. I can't wait to see Everybody Loves Gaschlongithorbintoninflubbertimont from Zeta III.

Hold on, a signal is coming in now...

[the_tsi]

W-E-A-P-O-L-O-G-I-S...

Man, it seems like gibberish. That doesn't really spell anything.

Re:Hold on, a signal is coming in now...

[Prof.Phreak]

W-E-A-P-O-L-O-G-I-S... ...possibly, it wouldn't have the same affect as huge fiery letters would.

DNA rox!

Eavesdropping on our Galactic Neighbors?

[Ronin Developer]

I wonder if we need a warrant or if we feel the new laws enable us to bypass this requirement?

I can only imagine one pissed off alien civialization talking us to task for this and laying waste to our planet.

RD

Re:Eavesdropping on our Galactic Neighbors?

[geekoid]

Then they should broadcast to us . \They are the ones tresspassing, or invading us' with their transmissions.

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.

Re:Faster than Light Communications

[meringuoid]

Personally I believe there must be a practical way to transmit data at faster than light speeds.

This implies that data can be transmitted backward in time; the two are equivalent. Are you prepared to accept the consequences of this possibility?

Be careful what you ask for

[DanielMarkham]

If the scientists turn this on and the first thing they see is an advertorial for buying planets with nothing down or growing extra tenacles while you sleep, I'm moving to a more quiet planet like Mars.

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.

Why?

[alexborges]

I dont see the point.

We all know...

They walk amongst us.

Re:Why?

[DonServo]

Tom Cruise? Is that you?

Re:Why?

[Kelbear]

I'm going to hunt for my very own "Boomer" right now!

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.

[andy314159pi]

I don't understand the phrase "fiber to the home."

Re:Fiber to the Home.

[maxume]

So kill yourself already.

It's pretty impressive that a childish monkey brain like Bush has managed not to pull the nucular trigger ain't it? Or maybe it isn't.

Scott Adams said something about Bush only being smarter than 90% of people, while most politicians are smarter than 99% of people, which makes people uncomfortable. An excellent thought.

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.

[amolapacificapaloma]

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 do imagine some advanced civilization bothering with us, but probably just to make sure we extinguish, just in case we are not even able to do it our shelves and in the process we kill some more peaceful aliens like those poor Martians.

Re:Fiber to the Home.

[chgros]

Yes, just like it's completely pointless to study those ignorant bastards that lived in the middle ages.

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.

Re:Fiber to the Home.

[Anonymous Coward]

Please, please PLEASE! Don't stop interacting with us! We need your words of wisdom. You would be doing a disservice to mankind by removing your intellect from public discourse. Someday, with your guidance, all with have fiber to the home and there will be no kooks. Please help us!

Re:Fiber to the Home.

[4D6963]

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.

lol, I love when people project themselves in their vision of what aliens might be like. It's not because you're atheist and that you think every smart person should be atheist or so that aliens are atheists and would despize getting in contact with god-fearing creatures.

Actually I'll never understand why so many people seem to think that aliens would have to be way superior to us and that because of that they would despize us as we are so striving to find even an alien bacteria.

Re:Fiber to the Home.

[exp(pi*sqrt(163))]

Oh, I don't know. I'd much rather discover a planet inhabited by warlike creatures like Klingons than a bunch of alien hippies.

I'm so ashamed of our whole species...

That's a personal problem that you have. I'd keep it to yourself if I were you.

Re:Fiber to the Home.

[crhylove]

Well every advance in technology so far has led to an eventual advance in ethics and morals. Albeit they can be lost again at the blink of an eye (morals and technologies), but certainly as the premier technological race currently known on the planet, envisioning an advanced technological race seems to strengthen the connections between technology and logic, and logic and morals. There are connections there, which is why most of the truly brilliant inventors and such throughout history have also been humanitarians on at least some level.

Advances in various fields further each other. This is a historical fact. One type of advance (technological) does not necessarily dictate for certain another type of specific advance (moral), but generally it DOES dictate another advance (any field). Frequently not the one(s) predicted, interestingly enough.

The fact that we are acting like animals though, with regard to torture and our current malaise towards actual democracy, means that very likely the aliens view us more as such, than say if we still were following the constitution, for one small example. I for one look at the cabal of ruthless corporate slaves running this country as little better than rabid barking dogs, begging for scraps off the Enron table. I'm not separating Dems or Reps, either, they are currently both completely corrupt and working at odds to American life, liberty, and happiness, and have been since even before Kennedy's assassination. I can hardly imagine anybody with even a basic grasp of economics, politics, ethics, or sociobiology (which I'm sure an advanced race would have some knowledge of) arriving at any other conclusion.

And as this same corrupt greedy government is "representing" all of us....

Woof woof, mother fucker (or as you stated, we might be little more than ants to them, solely because we act like it). I'm half surprised the aliens haven't already wiped us out hoping for some other species to evolve further, and in a more healthy way for themselves and the ecosystem they live in.

The media machine we live in has done so much irrevocable harm to ourselves, our families, our ethics, and even our science at this point, that if over half the population wasn't on Zoloft, there'd have already been violent clashes in the streets, I suppose.

It's easy to ignore it all and watch shit TV like American Idol though, when you are stoned, drunk, fat, and heavily under the illusion of happiness.

rhY

Re:Fiber to the Home.

[Simetrical]

Well every advance in technology so far has led to an eventual advance in ethics and morals.

Well, not exactly. Or rather, we today would view it as an advance in ethics and morals, but our ancestors would have viewed it as a degradation of ethics and morals. Who's to say that aliens would be more like us than our ancestors? Is there really some major trend in our morality that can be taken to be associated with technology?

Sure, there's democracy . . . but Rome certainly became a lot less democratic with the ascent of Caesar to the throne, even through centuries more of technological advances; China is rapidly advancing technologically, but is getting barely less oppressive; and so forth. If anything, I would say that democracy leads to technology, due to the spirit of freedom to explore the uncharted, not the other way around. The principles of the Enlightenment led to both liberty and scientific progress, the latter didn't lead to the former.

What other trends have there been in morality? Less harm to one's enemies? Okay, sure, I can see that. More technology allows gentler treatment by those in power without jeopardizing that power. But you have to have the desire to treat your enemies nicely first. I used the example of ants as creatures with no empathy, who place the importance of the group far above that of any number of individuals. It would be quite possible for an ant-like species to gain enough intelligence to reach us. As long as you have empathy for group members, you can prosper even while having no concern for non-group members (say, us).

The fact that we are acting like animals though, with regard to torture and our current malaise towards actual democracy, means that very likely the aliens view us more as such, than say if we still were following the constitution, for one small example.

Again, you're making assumptions about how aliens would perceive things that I think are unwarranted. Ants follow their queen, and have no compunction about killing those few members of the colony who don't. They certainly aren't big on democracy. That doesn't mean that ant-like drones (who cannot reproduce) need be mindless or unintelligent, just have different motives: they would have to place the good of the colony over anything else. Thus they could still invent advanced technology, it would just be to advance the hive and their curiosity rather than themselves and their curiosity. Primates, essentially all of whom can reproduce, often favor themselves or their friends or strangers rather than their groups.

As another example, consider computers. Computers are, in certain respects, more intelligent than any human, and in all other respects they're increasingly approaching the intelligence of humans, but they do nothing but what they're told. This perhaps above all shows the separation between capability and motive. Intelligence and curiosity need not come with even the slightest hint of compassion, and technology requires little more than intelligence, curiosity, and some degree of cooperation with others. It's perfectly possible, if not in fact likely, that we and any theoretical aliens would each view the other as depraved.

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.

Re:30 light years

[cowboygerbil]

Sod that. Just a couple of years until we get their Star Wars Christmas Special.

FM radio will be obselete a lot sooner than that

[Viol8]

A large number of countries have already been running digital broadcast radio services for a while now, the most popular being DAB. Here in the UK it covers (I believe) 90% of the population. Then of course you have satellite broadcasting not to mention all the internet based services.

I suspect in 20 or 30 years the the FM waveband will contain only non broadcast services in most countries or maybe even nothing at all except hiss and static.

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.

Re:Aliens

[pjabardo]

Maybe they follow the prime-directive and won't communicate with us until we have warp technology...

(theoretically)

[flickwipe]

The array could (theoretically) detect civilizations broadcasting in the same frequencies as our own society

The array could theoretically detect civilizations broadcasting hot nasty alien tentacle slime porn :D
Sign me up.

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.

Re:intelligent life on earth?

[Kev_Stewart]

Remember Star Trek IV when the aliens though just the marine mammals were intelligent.

...and the subsequent Star Trek VI The Undiscovered Country, complete with Scooby Doo ending thereby confirming the aliens' suspicions.

Re:intelligent life on earth?

[4D6963]

Remember Star Trek IV when the aliens though just the marine mammals were intelligent.

Well marine mammals are intelligent, actually, I don't see what's wrong with this claim. I'm not talking about intelligence in a quantitative manner as most people usually do by the way.

Re:intelligent life on earth?

[metachimp]

Evidence shows that marine mammals, and I am talking cetaceans here, not pinnipeds ( which are ocean-going dogs ), are quite intelligent. They only lack technology.

Re:intelligent life on earth?

[metachimp]

Crap. I forgot octopi, which are probably the most intelligent invertebrates on earth.

What if

[SnarfQuest]

What if no other culture in the universe is full of "people" trying to force their opinion on all others. They, then, would have no need of radio.

Re:What if

[Thraxen]

Ummm... they likely wouldn't even have radio technology if they didn't share their opinions with each other.

Comment removed

[account_deleted]

Comment removed based on user account deletion

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...

Re:Whoa, there...

[DarthVain]

Total elasped time of conversation: Minimum of 300 years (assuming lightspeed communication).

I think at the rate we are advancing one message will have little relavence to the next, assuming of course we don't at somepoint in the conversation master FTL.

Even more annoying would be the disparegy of technology, just think if one civ had some level of FTL and one didn't or at a much lower level. How annoying would that be. They could respond say near instantanous, and ours takes like 30 years to travel! I see somewhere in our future being called "Lagging Noobs" or something like that in an alien context/language.... Of course the upside is perhaps they will be annoyed so much as to give us the FTL technology (provided they have it), so that they can communicate easier with us. The downside of course is perhaps if they are that technology advanced, and that annoyed, perhaps they will just come and destroy us.

Re:Whoa, there...

[markbt73]

Yeah, but what if we end up mistaking their science fiction for their science?

Re:Whoa, there...

[BendingSpoons]

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.

I heard a distant strain of the Sesame Street song "One of these things is not like the others" when I read this. Kids, can you figure out which one of these things is not like the others?

-We're destroying our life-supporting environment
-We have nuclear weapons, capable of destroying most human life, on hair trigger
-Gay people have to go to Canada to get married

*Cue music*

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?

Re:A Cover Letter to Our Neighbours

[Jerf]

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.

Also, affluence-induced pessimism. Don't forget the affluence-induced pessimism. The better things get, the more time we have to monomaniacally focus on everything that isn't perfect yet.

Re:A Cover Letter to Our Neighbours

[PHPfanboy]

> Don't forget the affluence-induced pessimism.

Actually space programs seem to have pessimism-induced affluence. Because "they" could rule space, we need to plough millions into programs that may possibly at some unspecified point have some use ;-)

At last !

[Salsaman]

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

Re:FM radio will be obselete a lot sooner than tha

[Tony Hoyle]

Dab isn't popular in the UK... Low bitrates gave it a bad reputation and Freeview stole its thunder by being much cheaper. The one place where it could be exceedingly useful is in cars and car DAB stereos are as rare as hen's teeth, wildly expensive and require special DAB aerials to be fitted.

Anyway, back on topic... even a digital signal has structure. Once we can detect the broadcast we can tell it has structure by seeing things like regular repeating patterns (header blocks, etc.).

Even if the hypothetical alien was only broadcasting their version of morse we'd be able to tell it was nonrandom.

Too late

[Lord Bitman]

What we should be doing is beaming radio signals at distant protoplanets, hoping that by the time the signals get their, intelligent life has formed. Those life forms, inspired by our signals, could then devise a way to travel faster than the speed of light and get here at the exact moment we sent the signals in the first place.
Instant gratification!

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:Technology trends from our own planet

[TeknoHog]

Maybe I'm wrong but I would think that as a civilization becomes more advanced that the power of their broadcasts would decrees

In direct proportion to their spelling power, I would presume ;)

Re:Technology trends from our own planet

[east coast]

Yeah, I noticed that after posting. Oh well, they have my vote for an edit button.

Re:Technology trends from our own planet

[mqsoh]

Maybe we should build a huge transmitter specifically to broadcast our location. Maybe someone else has done the same.

Re:Technology trends from our own planet

[east coast]

That's not unreasonable to think that. It seems easy enough to do and, unlike many plans being tossed around, we have the technology to do it right now.

easier way...

[shawn(at)fsu]

All we have to do is just wait for the alien civilization to send their Overlords.

kickbanning

[camperdave]

The real question is whether we're going to get kickbanned for being n00bs.

Nah! We just won't be allowed into any of the interesting channels

It means....

[p_trekkie]

If you read the article, the authors show that signals from our current Anti-ballistic missile radar could be detected within a 30 pc radius of the earth using existing and proposed instruments that are designed to probe the epoch of reionization. That's one example they give, but they analyze the chances of detecting any generalized signal based on typical bandwidths and powers we use on earth.

The authors talk about the large number of instruments that are proposed or being built in the 50-300MHz band. That's where FM, tv, some satellite, and some radars lie, so any of those would be fair game for detection under this scheme. Also, they wouldn't be able to "listen in on the signal" with this method, only determine that someone was broadcasting, not what was being broadcast.

Oooh! Oooh!

[Mr Z]

Is it because I need to know something about the angle of my brother's envelope, communicated before I open it?

If god had a sense of humor

[CaffeineAddict2001]

The universe would be symmetrical and when we make first contact it's from earth's mirror planet.

This is Good News

[Anil Purandare]

Hopefully this will pave the way to future advances enabling us to detect traces of civilization on Earth!

subspace communication

[gaspar ilom]

What if their technology uses this, like the Star Trek communicator?

;)

KILL THEM NOW!

[multipartmixed]

They are studying us as undergraduate project in Weapology! Once the project is finished, they will probably terminate us!

Note that I said Weapology! They likely have weapons of mass disintegration! Quick, it is time to pave over their planet .. and turn it into an intergalatic bypass!

How likely are we able to detect a signal?

[Lazarian]

If a typical radio or television broadcast station transmits at a power of say, 500 kilowatts, what would be the greatest distance that one could detect the signal (with a reasonably sized detector)? I would think that broadcast stations would transmit omnidirectionally, and a signal would be reduced to a quarter of its intensity each time the distance is doubled. Given a distance of thirty light-years, would we even be able to pick up a signal, even if we knew a transmitter existed at a certain location? If I understand correctly, longer wavelengths like the FM or VHF bands would need a larger detector array to pick up, and perhaps using a dish to recieve those frequencies would be impractical to some extent (you'd need a really big dish to focus those wavelengths).

Does anyone know the math for something like this?

Will somebody please

[Provocateur]

...switch the knob the other way, to least Earth-like?
 

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

Re:Optical SETI is the way to go

[geekoid]

But radio spreadas out, where as light is LOS.

So if they aren't pointing to the Earth, how would we detect them?

Re:Optical SETI is the way to go

[ajpr]

The only drawback is that you have to aim the laser at something, whereas microwave/radio can emit in all directions.

Re:Optical SETI is the way to go

[Jorgensen]

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

Faster? In practical terms: not really. They may be able to transmit umpteen terabits/second but with latencies measured in decades, the bandwidth is of little significance. Any form of communication is going to be difficult, both for us and for the aliens - unless they've spent a few centuries talking to somebody even further away from us.

How much information is actually needed in each message before we should wait for a reply? A few kilobytes? I don't know about inter-civilisation etiquette, but if it's anything like dating, then giving out your complete life story before the first encounter is likely to be a bad idea...

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

Probably true. But one big problem with lasers is that they are directional - they need to be aimed. If we add lenses to make them somewhat unidirectional, the power drops accordingly which makes the whole thing pointless.

Lasers will only become relevant once we and the aliens have a fix on each other, so we both know where to aim the thing, and where to look for responses. A fraction of a degree off, and rest assured that the message is never received, so we have to aim precisely!

Unfortunately the effect of 'packet loss' increases with the latency, and with such enormous latencies it would not take many lost packets before the effective bandwidth drops to a trickle... I'd prefer reliable communication, lest they think we're giving them the cold shoulder treatment!

Re:Optical SETI is the way to go

[TheSync]

Your point is correct, you have to point your Optical SETI instruments (both the RX and the TX) to get the advantages of Optical SETI.

But within reasonable spheres of communication (10-1,000 light years), there is a whole lot more empty space than planetary systems, so all those radio waves going into empty space are wasted anyway.

So get a bunch of lasers and start pointing them at a bunch of stars, and get your telescopes (and they don't need to be very big) and start looking for the lasers pointing back at you that outshine their star within the small bandwidth of their laser line.

Earth not detectable anymore in 20 years

[SysKoll]

The interesting thing with radio transmissions is that the spectrum gets increasingly crowded. To compensate for this, we are deploying technologies that compress signals and spread transmissions over multiple frequencies. Sometimes we add encryption too (think 802.11 or Sirius/XM radio). However, all of this makes signal increasingly hard to detect, and any degradation in S/N ratio makes these transmissions look essentially like noise. Sure, today we have powerful AM and FM transmitters, but tomorrow, we might decide to replace them with other, more efficient technologies in order to reuse the freed frequencies for some other applications. Heck, with the cost of auctioned spectrum, you have powerful incentives to ditch inefficient transmissions if someone can make a better use of your frequencies. So it's likely that uncompressed radio transmissions will be almost non existent in 20 years due to spectrum scarcity. Our civilization will therefore be almost impossible to detect using the technologies described in TFA. It means that a civilization using radio transmissions can only be detected during a 100-year visibility window at most. Before that, they don't have powerful emitters. After that, they compress and spread everything. It well might be the reason why the Seti program hasn't found anything yet. And if this is true, our chances of being in the right place at the right time with our Seti receivers are quite small: we might very well have let slipped the visibility window of the closest civilizations. Hey, the Tau Cetians might have come and gone through the early radio age during our Renaissance, for all we know. Now they are only broadcasting encrypted, compressed stuff that looks like noise.

Re:Earth not detectable anymore in 20 years

[SeanMac]

The fortunate thing about this insight is that the only civilizations we should be able to detect by these means are ones we can crush, because they haven't discovered the benefits of spread spectrum technology :)

Re:Earth not detectable anymore in 20 years

[SysKoll]

I like the way you stink, err, think. :-)

Re:FM radio will be obselete a lot sooner than tha

[Simetrical]

Unless, of course, it's heavily compressed. Compression, after all, increases apparent randomness. Order implies redundancy if I can guess what the next bit of information is going to be, it's a waste of bandwidth to send a whole bit to tell me. Send part of a bit if my guess is right, more than a bit if I'm wrong, and you'll save on bandwidth.

For instance, in the English language Q is almost always followed by U. This is nonrandom. As soon as I receive a Q from you, I can be almost certain that I'll get a U next. So instead of wasting that extra letter, we can save a bit of bandwidth by deciding that "Q" means "QU" and "QU" means "Q". Then Q is no longer usually followed by U, which increases the randomness and reduces the size.

We might still be able to figure it out, but I don't know if it's a sure thing. It could be I can't claim to be an expert on compression.

Re:Dectecting Life On Other Worlds

[MLease]

They wouldn't have started out more advanced than we are now. It seems reasonable to assume that most advanced civilizations would at least have passed through a phase of using radio technology. They may have stumbled across a different or better technology first, but if that's the case, we simply don't know what else to look for (if we did, we'd be using it ourselves). Looking for radio waves is something we do know how to do, and if we want to look for ETI, that at least seems to be a reasonable starting point.

-Mike

Earth-like, huh?

[Mursk]

I think one 'Earth-like' civilization is enough for me, thanks.

Not true

[geekoid]

" he now instantly knows that your slip of paper is white."

That in it self is information.

Re:Not true

[Jerf]

Yes, but it is information that you received at the speed of light from the original transmission. You didn't communicate something from one target to another at faster-than-light speeds, because you have no control over what you receive.

This means that you can receive a signal from the original transmitter at the speed of light, but that's no big deal.

I'd like to point out to both you and everybody else sputtering "but... but... but...!" that entanglement may be an exotic mathematical phenomenon, but it is very easy to create entangled photons in a laboratory. Very easy. And true FTL communication will be pretty much a guaranteed Nobel prize, so it's not a lack of motivation. If there was some easy way to exploit entanglement for FTL communication, it'd have been done. Most like fifty years ago.

I submit that if your understanding leads you to believe that there must be a way, or at least doesn't prove that there isn't one, it's your understanding that is wrong, not the universe and not people who really know physics.

Re:Not true

[inviolet]

That in it self is information.

While it is pedantically true that he possesses information about something, it is not information that was transmitted by the sender.

SETI@Home Rank

[syntap]

You mean my top .005% rank was all for nothing? Drat. Time to put my 200-core SETI calculation cluster to work as an HDDVD/BRay decryptor.

Or will they care?

[lonechicken]

Maybe a civilization in some distant galaxy, 300,000 earth years more technologically advanced than ours still hasn't figured out the whole "How the hell do we travel to the nearest star system in any reasonable amount of time?" thing. So they're like, "F this, let's just worry about our species' survival inside our own region of the galaxy." And are working on a Dyson Sphere or something. Our resources may be better spent creating parallel universes that we can somehow travel to through a box portal. Like leprechaun universe or pirate universe.

Wrong!

[celtic_hackr]

Any Earth-like civilizations within 30 light years are surely able to detect us now as well! This much is certain. However, these civilizations are all now up to 30-80+ years more advanced than us, provided they haven't made themselves extinct. Since we are viewing the signals that are up to 30 years old, and considering that we have been transmitting detectable amounts of such signals for let's say 50 years (for a round number). Considering where we are along the path of space travel, a civilization 30 years more advanced is quite probably capable of interstellar travel.

Hence, now at least we will be able to pinpoint the most likely home planets for our soon to be new overlords, whom I welcome and offer up our political leaders to them as sacrifice and homage.

Sadly, I predict we'll find nothing.

[Pedrito]

Using some fairly basic math, it's pretty easy to show that a species only marginally more advanced than ourselves could easily colonize the entire galaxy in 5-10 million years. That's all sub-light travel and provides a hundred years or so for each colony to develop the necessary technologies and industries to send out further colonies. 5 million years is NOTHING in terms of how long our galaxy has been around.

Obviously this would only apply to adventurous, explorative type species like ourselves, but it's a fairly obvious thing to do for any species capable of doing it and wishing to avoid becoming extinct because of a natural (or self-made) disaster.

Now, given the incredibly short period of time required to colonize the entire galaxy, probability says, the one that arrives at that technological level first. Now, it's possible some species has already done it and hidden themselves from view, in which case, it's unlikely we'll find them anytime in any of our lifetimes. The other possibility is that we're that species and nothing else in our galaxy has come close, so the only other potential we'd have to find other species is in other galaxies which is way too distant for any sort of communication to be viable. I mean, we might be able to detect an incredibly powerful transmission, but the reply time would be so incredibly long no sort of conversation could happen (unless, of course, we figure out a faster than light travel and/or communications method).

My point being, I don't think we'll find anything in our galaxy. I'm afraid we're very likely alone. But that doesn't mean searching is a bad idea. I was wrong once before.

Fine, but remember...

[xactuary]

Fine, but remember... unless otherwise proven, To Serve Man shall be considered a cookbook.

Doesn't work in quantum mechanics

[p3d0]

You might think that particles have some real quantum state even if they haven't been observed yet. In fact, there are experiments proving that this is false: the particles are in a quantum-entangled state (ie. they are "in both states") until they are observed. If you assume they are in some state until observed, you will reach an incorrect conclusion regarding the outcome of such an experiment. This is a very hard concept to accept for many people, and physicists wouldn't accept it either if it weren't for the fact that mountains of evidence demonstrate it conclusively.

numbers

[phlegmofdiscontent]

Hate to be a spoil-sport, but they got their numbers wrong. Within 30 light-years (a little less than 10 parsecs), there are only about 360 known stars (about 240 star systems). We haven't discovered all systems within 10 parsecs, but current estimates are about 500 stars. That being said, the number of stars that are likely to be inhabited by intelligent, technological civilizations is far far less than that.

Ah I see...

[paniq]

...so broadcasts could be marketed to planets like ours later on, perhaps for BFD-DVD players with an appropriate planet code.

10-500 pc, not 30

[benhocking]

If you read the article, the authors show that signals from our current Anti-ballistic missile radar could be detected within a 30 pc radius of the earth using existing and proposed instruments that are designed to probe the epoch of reionization.

Actually, according to the article linked above, it's 30 lightyears, or about 9 pc. The paper, however, mentions ~10^{1-2.7}pc or about 33-1600 lightyears.

Re:10-500 pc, not 30

[p_trekkie]

Sorry, by article I meant the journal article, not the press release type article, which I fully admit to not bothering to read.

Also, the hundreds of parsec possibility mentioned are not currently feasible because they depend on the Square Kilometer Array (SKA) which at the moment only exists on paper. It currently is in the early design phase and is not yet funded. Thus, if they try to get telescope time for this SETI project today, they will only be able to detect a signal out to 30pc according to one of the figures in the paper.

Butl from the paper...

[benhocking]

Ah, but from the paper:

will be able to detect radio broadcast leakage from an Earth-like civilization out to a distance of ~10^{1-2.7}pc

And, as anyone can tell you, ~10^{1-2.7}pc is ~33-1600 ly. (1 parsec = ~3.26 lightyears)

Radio is soooo Passe

[Wingsy]

It never ceases to amaze me at these SETI type astronomers who just assume that other civilizations use radio waves for communications. I have it on good authority that most civilizations who stumble onto radio waves only use that form for a couple of hundred earth years, after which time, if they haven't blown themselves up, they move on to millimeter wave gravity waves. As we all know, garvity waves pass through anything without even the slightest bit of attenuation or distortion. They're all listening for something that isn't there.

Space religion nutjobs unite...

[Ingolfke]

Ah I love these posts because they bring out the most wonderful from of complete nutjob, the one who embraces science and at the same time embraces complete and unrealistic faith that against all probability there is life just like us on another planet.

This is a complete waste of money and is essentially a big grandiose "fuck you" to anyone who is starving or dying of a curable disease anywhere on the planet. Great job Mr. "Theorist"... sounds like a term that is completely replaceable by "jack off".

Re:Space religion nutjobs unite...

[Ingolfke]

Marshall Applewhite is that you?

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

Dear Earth...

[sjs132]

Shut the F$@# UP! We are trying to meditate up here.

Signed
Your space neighbors

PS.. PLEASE Stop all broadcast of American Idol before we come and FORCE it off the air.

Re:FM radio will be obselete a lot sooner than tha

[JavaLord]

That sounds qite cool.

Why Rome didn't build a steam engine...

[dotMantle]

The Birth of Plenty postulates that four qualities are needed for ongoing development and wealth creation, such as that experienced by the west over the past 300 years:

1. Property rights (you own what you build and invent)
2. Access to finance, and limited liability
3. Effective transport mechanisms
4. Mechanical power

In the book, the author explicitly addresses why Rome (and others) didn't develop better tech... the senate stripped property rights away from the plebeians, and crushing penalties on failing to repay a loan. (Similar conditions applied to most other civilizations.) So Rome didn't develop the steam engine because it didn't have anyone willing to finance (or repay) the investment required to invent the needed technology. It wasn't until the sixteenth century that Holland got these conditions right, and began sustained growth. England shortly followed suit and triggered the Industrial Revolution. All the progress since then has been a result of the sustained growth, plus the exporting of England's legal principles around the world. As a result, the evolution of law over the 'Dark Ages' is a key part of modern society.

A few reasons why ET life is extremely likely

[LuxMaker]

1.) Hydrogen is the most abundant element in the universe.

2.) H2 + O2 + Energy(solar) -> Water. Hence water should be fairly common in the universe.

3.) Carbon, Hydrogen, and Oxygen organic chains should form elswhere given that it happened here on Earth so it should be likely to happen elswhere given that the universe is so insanely huge (with the right materials).

4.) Worms found in one of the polar regions of Earth were found to be thriving, so temperature restrictions may be not as restrictive as we might think.


The question we should ask ourselves is: Are we ready to handle the idea of other life outside of what we know?

Re:What are the odds

[ArcherB]

I would say pretty high. Radio waves are a part of nature. We use them because they are the best solution for broadcast transmissions and for mobile communications.
The systems are simple and work well. Odds are pretty good that they would have many of the same needs as we do and they share the universe with us so the solutins could be very similar. After all how long have we used the wheel?

Excellent point. However, we don't know what these aliens are like. Their eyes may see in radio where we see in light. Your common cordless phone would be like a sparkler to these people.

Then again, you're probably right. I don't know beans about radio except it's the only musical instrument I can play!

empathetic cultures

[snooo53]

I dunno, I think our civilization would be pretty attractive to an alien one. We have an understanding of science, and therefore presumably some common ground with them. We have many interesting and diverse cultures. We're likely different enough from them that they'd want to learn about us, much the same as we'd want to learn about them. If they're so advanced morally compared to us, surely they'd easily able to see past the charade of politicians and intolerant and close-minded people. I would bet somewhere deep in their past they too had the same conflicts that arise from evolutionary competition, and could empathize if nothing else.

There are a lot of people here living in the stone age, morally speaking. But I think there's a lot more that would live up the expectations of civility if given a decent opportunity.

Forget that

[JumperCable]

The first message we sent to another planet better be "Hello World."

Laser communications is the way to go

[wikinerd]

Advanced alien civilisations are probably communicating in space using LASERs. We ought to search for lasers, not radio signals.

Intgelligent Life

[Dabido]

Okay, sounds like they have a way to find Earth-Like civilizations. But what should they do if they want to find intelligent life?

Re:What are the odds

[LWATCDR]

Eyes that see in radio waves would be pretty useless. To have any type of resolution they would have to be huge. Compare the size of a radio telescope to an optical telescope. That size is based on the wavelength. Also I am not too sure that you could make an organic radio receiver.

Think about the richness of our senses eyes provide a high band width direction sense. Ears give you a lower bandwidth but longer range omni direction sense.

I would bet that any life that develops technology would tend to have the same senses as we do becuse they work well.

Puts a totally new meaning to.....

[avanaardt]

"Hello World!"

Re:Please translate from Marketing-speak

[instarx]

Still doesn't solve the embarrassing situation for the giant cockroaches.

We can only hope the other civilization is thousands of years ahead of us in bug-spray technology.