Detection of Earth-like Civilizations in Space Now Possible 345
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."
Knowing Your Neighbours (Score:5, Interesting)
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 (Score:5, Insightful)
And to quote Carl Sagan, "Absence of evidence is not evidence of absence."
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And he stretched out his noodly appendage [venganza.org]
Re:Knowing Your Neighbours (Score:5, Interesting)
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 (Score:5, Insightful)
Re:Knowing Your Neighbours (Score:4, Funny)
"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.
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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 lack
Re:Knowing Your Neighbours (Score:5, Insightful)
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.
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Re:Knowing Your Neighbours (Score:5, Interesting)
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.
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A long, boring, convoluted logical argument (Score:3, Interesting)
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:
Re:Knowing Your Neighbours (Score:4, Insightful)
I'll take your quote and raise: "Extraordinary claims require extraordinary evidence"
Re:Knowing Your Neighbours (Score:5, Insightful)
Re:Knowing Your Neighbours (Score:4, Informative)
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 (Score:5, Funny)
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.
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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.
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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 becom
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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.
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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 wou
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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 othe
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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 imm
What does "Earth like" mean? (Score:4, Interesting)
What exactly is it detecting? FM radio? Television? Radar? Emissions from cars? Would it detect a working telegraph?
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It means.... (Score:2)
The authors talk about the large number of instruments that are proposed or being built in the 50-300MHz band.
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Re:Knowing Your Neighbours (Score:5, Funny)
"Earth-like" civilizations? (Score:5, Funny)
So we're going to pick up an alien version of "The View"?
Re:"Earth-like" civilizations? (Score:5, Funny)
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Re:"Earth-like" civilizations? (Score:4, Funny)
With Jabba the Hutt [wikipedia.org] instead of Rosie O'Donnell [starwars.com]? Oh, wait...
any physicists out there? (Score:5, Funny)
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Re:any physicists out there? (Score:5, Informative)
You are thinking of quantum entanglement, aka "spooky action at a distance".
It cannot be used to transmit information. Think of it this way:
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.
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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 t
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Prayer?
Interesting idea - but same old problem (Score:2)
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Impossible! (Score:5, Funny)
The respective governments all attempted to stop this legistation getting in but the RIGA had bigger guns!
Hmm. (Score:2)
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 p
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Re:Hmm. (Score:5, Insightful)
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.
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FM radio will be obselete a lot sooner than that (Score:2)
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.
Re:FM radio will be obselete a lot sooner than tha (Score:2)
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 hypothet
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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.
Obligatory (Score:5, Funny)
And I, for one, welcome our new nearby, low-frequency-emitting overlords.
And I would like to remind them that as a net.geek, I could be useful in rounding up others, to toil in their oneline goldfarms.
Let's hope they're not like us (Score:4, Funny)
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. .
KFG
Window of opportunity (Score:3, Insightful)
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.
It's already too late ? (Score:2, Funny)
http://en.wikipedia.org/wiki/Video_Killed_the_Rad
So now we should check for video signals from these stars !
Not a big area (Score:5, Interesting)
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.
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kickbanning (Score:2)
Nah! We just won't be allowed into any of the interesting channels
Re:Not a big area (Score:5, Interesting)
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.
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Hopefully the message wouldn't be "All your base are belong to us."
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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.
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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 approachin
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The Flipside (Score:2)
Hold on, a signal is coming in now... (Score:2)
Man, it seems like gibberish. That doesn't really spell anything.
Eavesdropping on our Galactic Neighbors? (Score:2)
I can only imagine one pissed off alien civialization talking us to task for this and laying waste to our planet.
RD
if we're only now uncovering this new technology.. (Score:2, Insightful)
Faster than Light Communications (Score:2, Insightful)
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.
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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 (Score:2)
my question is... (Score:4, Funny)
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 (Score:2, Insightful)
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 nex
Fiber to the Home. (Score:5, Interesting)
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. (Score:4, Insightful)
Well, what are we looking for...? (Score:3, Insightful)
30 light years (Score:2, Funny)
Aliens (Score:2, Interesting)
intelligent life on earth? (Score:3, Interesting)
Remember Star Trek IV when the aliens though just the marine mammals were intelligent.
What if (Score:2)
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Whoa, there... (Score:5, Funny)
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...
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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
A Cover Letter to Our Neighbours (Score:2)
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
At last ! (Score:4, Funny)
Too late (Score:2)
Instant gratification!
Technology trends from our own planet (Score:3, Informative)
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.
easier way... (Score:2)
If god had a sense of humor (Score:2)
Optical SETI is the way to go (Score:3, Interesting)
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 [princeton.edu]
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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?
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Who needs anything else?