New Paper Offers Additional Reasoning for Fermi's Paradox 774
KentuckyFC writes "If the universe is teeming with advanced civilizations capable of communicating over interstellar distances, then surely we ought to have seen them by now. That's the gist of a paradoxical line of reasoning put forward by the physicist Enrico Fermi in 1950. The so-called Fermi Paradox has haunted SETI researchers ever since. Not least because if the number of intelligent civilizations capable of communication in our galaxy is greater than 1, then we should eventually hear from them. Now one astrophysicist says this thinking fails to take into account the limit to how far a signal from ET can travel before it becomes too faint to hear. Factor that in and everything changes. Assuming the average communicating civilization has a lifetime of 1,000 years, ten times longer than Earth has been broadcasting, and has a signal horizon of 1,000 light-years, you need a minimum of over 300 communicating civilizations in the Milky Way to ensure that you'll see one of them. Any less than that and the chances are that they'll live out their days entirely ignorant of each other's existence. Paradox solved, right?"
It's quite clear what the reason is (Score:4, Funny)
We humans are God's only children. That's why there's no one else in the universe. And the universe was created 6k years ago. Duh! Scientists... what useful things have they ever done other than bring up heresy?
Re:It's quite clear what the reason is (Score:5, Funny)
...the universe was created 6k years ago.
Hey - There's no room for rounding if you're going scriptural on us. The Earth's creation started the night before Oct 23, 4004 BC. [wikipedia.org] (In case anyone was wondering, Earth is a Libra.)
Re:It's quite clear what the reason is (Score:5, Funny)
Is that Julian or Gregorian?
Re: (Score:3, Informative)
Proleptic Julian calendar. [wikipedia.org] Dates in the BC range (and all the way into the late 16th century AD) are typically assumed Julian unless explicitly stated Gregorian. Although I have no idea what the proper technique would be to handle the who Julian leap-year mess and figure out whether Earth really is a Libra or actually a Scorpio with a funny birthday. If only Ussher was still around we could ask him.
As a side note (as if this whole thing isn't a side-note), Lightfoot [wikipedia.org] also put the Earth's birthday near the
Re:It's quite clear what the reason is (Score:5, Interesting)
(Except of course that all the dates for the signs are fixed as they were in the time of the Ancient Greeks, so we're already off by a whole month. If you're a Libra the sun is actually in Virgo on your birthday.)
This also means that the autumnal equinox in 4004 BC was somewhere around the end of June.
Re:It's quite clear what the reason is (Score:5, Funny)
That explains the drama-queen mood and temperature swings, then.
Re: (Score:3, Funny)
...five, six, seven... so it finished on Halloween? That explains a lot.
Re: (Score:3, Informative)
Might want to try that math again, hot shot. Hint: 23 + 6 = 29.
Re: (Score:3, Insightful)
Um, how about this? 23, 24, 25, 26, 27, 28, 29. That's 7 days, inclusive, and given the GP's statement, the 23rd would be the first day. So you failed twice. First, 23 + 7 is 30, not 31. Second, you forgot the inclusion note.
Don't worry, you're not the first person I've met who fancied himself a nerd and couldn't do date math properly.
...
I'm sure there's a joke in there somewhere about nerds not getting dates...now it all makes sense.
Re:It's quite clear what the reason is (Score:5, Funny)
True. But it appears the Almighty actually spent his day of rest at the mall looking for a good costume to scare the bejeesus out of Adam and Eve.
Unfortunately, by the time he got there, all they had left was a dorky snake costume.
Re: (Score:3, Insightful)
Ahh wikipedia. Nothing like seeing an article refute itself mid-paragraph.
Re:It's quite clear what the reason is (Score:4, Insightful)
(In case anyone was wondering, Earth is a Libra.)
Not to nitpick or anything, but the Earth cannot have a zodiac sign, since the latter is usually defined as the constellation in the ecliptic that the Sun was present in. Which presumes that the observer was located on the Earth. Ergo ...
Re: (Score:3, Informative)
Re:It's quite clear what the reason is (Score:5, Insightful)
Fermi's paradox is paradoxically absent any real facts. We know not nearly enough to know if it's even relevant.
For example, one prime assumption is that alien life would communicate on the EM spectrum someplace using technology similar enough to ours to be in a form that we would understand or recognize. Yet dolphins are quite intelligent, and we have no idea what they are saying. If we can't decipher communication in a biological form that's based on the same exact biology as ourselves, that is 99% identical at the cellular level, how can we justify our arrogance in believing that we'd know truly alien communication if we saw it?
Obviously, if we did come across some communication on the EM spectrum that we were to show wasn't some mere physical process, we'd have proof of alien communication or related phenomena. But there's no evidence at all that they would. In fact, it's rather unlikely that we will ourselves, in just a few years: take a look at spread spectrum transmission [wikipedia.org] for a method that we already use today in many uses that would be virtually undetectable by SETI.
Fermi's paradox is based on a large number of assumptions of scale that are, quite frankly pulled from Fermi's backside, and aren't even well supported by technological developments since its inception. They are the best assumptions available, but they demonstrate nothing other than a weak foundation for conjecture.
And if some of those assumptions are already demonstrated irrelevant with applicable technology HERE, TODAY, how can we give Fermi's paradox any more than the time of day?
Re:It's quite clear what the reason is (Score:5, Interesting)
Actually, IIRC, the Pope made a declaration a while back that there's nothing biblical that bars the existence of extraterrestrial life. For many people who are strongly devoted to one religion or another, even finding a note from their messiah announcing "Just kidding - I didn't think that y'all were going to take me so seriously. Hopefully after I die, somebody will find this and avoid any real disaster," would defer them from their beliefs.
Re:It's quite clear what the reason is (Score:4, Interesting)
Re: (Score:3, Funny)
You may want to rephrase that ;)
Re:It's quite clear what the reason is (Score:4, Funny)
Either the Vatican are hedging their bets, or they're on to something the rest of us don't know (yet).
Re:It's quite clear what the reason is (Score:4, Informative)
Either the Vatican are hedging their bets, or they're on to something the rest of us don't know (yet).
They have seen the jet planes.
Re:It's quite clear what the reason is (Score:5, Informative)
The Catholic Church also accepts evolution as "how God did it" so good luck trying to get through to the Creationists who obviously don't want anything to do with St Peter's successor.
Re:It's quite clear what the reason is (Score:5, Insightful)
Re: (Score:3, Interesting)
If you take the creation story in Genesis metaphorically (lots of Christians do),
You can't do that if you're talking to Americans, which most of us on Slashdot are. Here, most Christians believe the literal story of Genesis. What the pope says is irrelevant, since most Christians in America believe Catholicism to be a false and non-Christian religion.
Re:It's quite clear what the reason is (Score:4, Insightful)
Most Christians? I take issue with that, so here is the obligatory [Citation Needed].
As long as we're talking bullshit, I'd say that most Christians do not take the creation story literally.
Again, either you're not an American, have never been to America, or if you are American, you've spent your entire life in San Francisco. How exactly do you think GW Bush was elected twice? Have you never heard of the "evangelicals", a huge and fast-growing religious/political group? They're not quite big enough to win national elections all by themselves (that's why Obama won this time, since Bush did such a horrible job and the economy's in the toilet), but they're a very large and powerful force. And if you didn't realize it before, "evangelical" equals "fundamentalist".
If you want citations, just google for "evangelical christians in America".
Re:It's quite clear what the reason is (Score:4, Interesting)
Summary:
A) Aliens come to eat us
B) Aliens might contradict our world-view
C) Aliens probably can't/won't communicate with us, so it just adds more inconclusive doubt. Which only brings us pain.
D) To non-believers, aliens represent an 'I told you so!!!' moment.
E) Believers are put-off by the 'I'm sure I can say I told you so!!!!' movement
Details:
Great question. But here's my take:
You might vote republican because it's pro-life, anti-stem-cell-research, anti-gay
You are pro-life/ anti-stem-cell because abortion is soul abuse
Abortion is soul-abuse because 'God says so'
'God says so' because that's how you were brought up. (Killing is wrong) - (even though it's technically Murder that is wrong - specifically subject to human interpretation)
You know that's how you were brought up because you and your peers are reminded of it in church weekly.
Your church is right because it is 2,000 years old. (or otherwise derived from an Angel affirming the truth to 1 recent historic figure)
So now if you start showing how your church was historically wrong, you can start backing out the logic until Christopher Reves can be saved!!
Obviously you're stuck until the 'feeling right' part is overcome. Religion is more-often a justification for your personal world-views. That's often why people change their religion.
So Lets take a separate path.
The church is correct because it 'feels' right [to me].
The church might feel right because of its simple mantra: Jesus Christ is my personal savior.
Jesus is my personal savior because I need to be saved.
Jesus CAN save us because people say he performed certain random semi-useful miracles (though 60 to 100 years after the events)
I need to be saved because I'm a sinner.
Alternately, I need to be saved, because I'm insecure and need to feel the safety net of a super-power taking care of me during my time of need. There is no biblical justification to this. In fact, Jesus parables specifically contradict this (believers are destined an even harder and more arduous life). It is always people that perform miracles in the New Testament. Natural miracles were part of the old Testament. People were later embued with Jesus-like-powers. Yet they weren't saviors themselves, just messengers who re-affirm the gotta-believe-in-Jesus mantra.
I am a sinner because I screw up a lot (Great 4,000 years ago, but doesn't sit well today, so lets try again)
I am a sinner because of original sin.
Original sin exists because of Adam and Eve.
Adam and eve exist because of the bible is the word of God and is NOT metaphorical. It is a historical record guided by the hand of God, and worthy of extrapolating truths by reading in between the lines.
So miracles aside. So now if you start mucking with the truths of this or that, you obviously can't read in between the lines. A sane/rational person thus would ignore ALL texts not explicitly outlined when presented with factual errors in the bible. Though original sin and homophobia are clearly layed out - so you could still argue that point. Most people, however, will still read in between the lines when it's convenient to promote their cause (cognitive dissidence).
For example, homosexuality is one of MANY punishable by death sins in the old testiment. Put right next to eating a cheese-burger. Yet we 'ignore' the cheese-burger death-sentence through the 'personal savior' clause - fulfilling the old testament.. Yet even though Homosexuality is a death-filled God vengence, it is never mentioned again in the new testament, it's conveniently allowed to survive, while cheese-burgers are silently acquitted. Ultimately 'common sense'
Re:It's quite clear what the reason is (Score:5, Insightful)
Religion and science are fundamentally opposed on the issue of epistemology. In science, everything has to be compatible with observations or it can't be properly claimed to be true. In religion, truth is established by authority: the preacher or the bible or (fill in the blank) says it's true, therefor it's true.
This explains why some people are so enthusiastic about finding errors in religion. Logically, once the flaw is found, the authority is dethroned, and the whole religion should collapse. Alas, religious people can be remarkably immune to logic. So although it is worthwhile to point out religion's inconsistencies (both internal and external), it won't change the mind of most people who want to believe.
As an illustration of the division between religion and reality-based belief systems, consider what happens when something in religion is found to be in incontrovertible agreement with observations. If it's an old event, then the item ceases to be religion and becomes history. If it's some principle of behavior, then it ceases to be religion and becomes part of the soft sciences like psychology or political science, or (worst case) part of the humanities such as ethics. When something is proven, it's no longer religion.
Re:It's quite clear what the reason is (Score:4, Funny)
Re:It's quite clear what the reason is (Score:5, Insightful)
Wrong.
Faith can be falsified quite easily. I once had faith that creationism was the truth. I read plenty of books and pamphlets to back up that idea. But then one day, it occurred to me that in order for creationism to be the truth, there had to be a vast scientific conspiracy out there, ranging from paleontologists to biologists.
So I started paying attention to science.
I now know that I was incorrect. My faith was wrong. I was blind and now I see.
Re:It's quite clear what the reason is (Score:5, Funny)
Then I for one welcome our Alien Overlord. Oh wait, I'm atheist. Shit, now I'm all confused.
Re:It's quite clear what the reason is (Score:5, Insightful)
Nature holds no distinction between "can" and "should". Morality is a product of idealism and virtue, both properties primarily ascribed to sentient beings: we have chosen a way to live that we consider "right" (whatever that is) and we are willing to restrict our behavior to accommodate this ideal.
It's one of the noblest things about us, and I hope that sentient extraterrestrial life would also possess a sense of morality. But don't think for a second that nature itself is moral. Nature is completely impartial and completely absolute. How good or evil someone is does not factor into how quickly he falls if he walks off of a cliff.
If that sentient life poses a threat to us, we can attempt to resist to the limits of our power. Should our capacity prove inadequate, we will be destroyed no matter how much morality we possess or how much morality that alien civilization lacks. Is it "ok"? No, it's awful! But that is how reality works. Species go extinct, volcanoes erupt, and people starve despite our best efforts. We can't shape reality by our whims alone; we can only try to change things by working within its rules.
This is true irrespective of religion. Unless you believe God is going to save us from the aliens... in which case maybe He already is, by keeping them from contacting us. Now there's an interesting solution to the Fermi paradox.
Re:It's quite clear what the reason is (Score:5, Funny)
I, for one, found his ideas intriguing and wish to subscribe to his newsletter.
No heat death for us (Score:3, Funny)
Assuming the average communicating civilization has a lifetime of 1,000 years...
Damn - We've got less time than I thought. Here I've been rooting for heat death. =(
What paper? (Score:4, Informative)
No link to anything but Wikipedia and a blog?
Re:What paper? (Score:5, Funny)
I don't know about you, but I prefer a link to a blog over the actual paper. Mostly because I don't speak Astrophysicsese.
I went ahead and clicked on the blog for you, and the link. Here's the paper (You can get a PDF if you want), it was submitted to the International Journal of Astrobiology.
http://arxiv.org/abs/0901.3863 [arxiv.org]
I understand your reluctance, after all you're the one who posted:
http://slashdot.org/comments.pl?sid=1112493&cid=26694469 [slashdot.org]
Don't worry, you can continue to click on links out of curiosity. I put one above, go ahead, click it. You know you want to. everyone else is clicking it. Now with more fiber, and it cures Alzheimer's too.
Re:What paper? (Score:4, Informative)
Now THAT is funny!
Solved? (Score:3, Insightful)
"Paradox solved, right?"
No. Some planets suitable for life have almost certainly existed in this galaxy for billions of years longer than the Earth. By now, one would expect there to have been civilisations that spread throughout the galaxy and therefore brought Earth within detection range of their signals...
Re:Solved? (Score:5, Interesting)
And if they're communicating by some mechanism that we can't read? E.g. the equivalent of "subspace radio".
Or maybe it's a point to point via laser (see Niven's Known Universe).
Re:Solved? (Score:5, Funny)
Exactly. Maybe all those "crazy" people are actually talking to aliens.
Re:Solved? (Score:5, Funny)
No - Those people really are crazy.
The aliens talk only to me and I have the good sense not to answer them (at least not out loud). I just carefully carry out their instructions and try to get mixed up with those crazies.
Re:Solved? (Score:5, Interesting)
True. The calculation of 1000 years seems a bit too long. We can't figure out how to shorten it because we don't know how long we're going to be using broadcast signal based communication as opposed to some other more direct means.
Besides . . . attempting to extrapolate with so many unknowns is, at best, an exercise in postulation. At worst, it is dangerously misinforming.
Re:Solved? (Score:5, Funny)
Right now our civilization is like a closed source application running on a dev box off the network. If the hard drive dies, the code is toast. But as soon as you get that code in Git, its a whole lot harder to kill.
Ok, so that was a terrible analogy.
Re:Solved? (Score:5, Interesting)
Re:Solved? (Score:4, Interesting)
First,you assume interstellar travel is possible. What if it isn't? What if the only ways to travel in space are no much better than the ones we know? We'd be all restrained to our own star systems. Perhaps we can have space stations and colonies in nearby planets and moons, but not much more than that. Perhaps they can't be self sustainable. Perhaps the likehood of finding another environment in another planet that can be converted to supporting life without an extreme expense of energy is extremely low.
AFAIK, the Fermi paradox has nothing to do with interstellar travel. It only assumes things that we already know, and hence are definitely possible - using radio waves as a means of communication. I myself think this may be too much of an assumption.
Re:Solved? (Score:5, Insightful)
The 1,000 year thing seems like the weak point of this theory.
Actually, the estimate of the probability of the kind of intelligence that makes complex machines is a bigger problem, and a plausible solution to the paradox.
We have ample evidence that if a thing is possible at all, evolution will reproduce it many times. Wings, fins, eyes... all of these optima have been found many times, across genera and families and whatnot. By one estimate the eye has evolved independently a couple of dozen times, based on the proteins used in the retinal structure.
There was an article here on /. a while back pointing out that two birds previously believed to be related were the result of convergent evolution. Evolution finds the same optima over and over again.
The kind of intelligence that makes complex machines has evolved on Earth exactly once, and that is the only kind that is of interest in Fermi's Paradox.
Furthermore, the current best guess at the evolutionary driver of kind of intelligence that makes complex machines is that it's a peacock's tail, and extravagant sexual display that had relatively little utility outside of attracting a mate or two. Therefore the whole "making complex machines" aspect of our intelligence is more-or-less an accident, not the result of direct selective pressure at all.
Men are very slightly better at some spacial reasoning than women because we hunted more, maybe, but that very slight difference is a measure of how little practical, non-sexual, selective pressure their actually was.
So based on what we know at the moment about the kind of intelligence that makes complex machines it seems likely that the resolution to Fermi's Paradox is that it is unbelievably rare. We may well be the only species to have such an intelligence in our galaxy, although even I have a hard time believing we're the only one in the universe. It could be, though.
Alternate solution: High-efficiency communication (Score:5, Interesting)
The calculation of 1000 years seems a bit too long. We can't figure out how to shorten it because we don't know how long we're going to be using broadcast signal based communication as opposed to some other more direct means.
My own contribution to the debate:
As technology advances the limited amount of available bandwidth becomes more valuable, while costs of utilizing it drop. The civilization migrates its bandwidth use from simple, extremely redundant, coding schemes (like AM and FM) to subtle, highly-efficient schemes that are virtually indistinguishable from thermal noise (like OFDM). They also use spacial multiplexing to re-use the same bandwidth over and over at various locations. This buries the few redundant parts of the signal (like the pilot subchannels used for synchronizing the receiver) in interfering noise.
The result is that, after a fairly short time, at a distance they are virtually indistinguishable from a hot black body - and lost in the sagans of other hot things in the galaxy.
Our first AM voice radio broadcast was at the end of 1906. 102 years later we're taking a big step in the transition to OFDM-or-CDMA-everywhere by shutting down "analog TV" and replacing it with OFDM-based digital. AM and FM are already using digital variants to squeeze more out of their spectrum. Any bets on how long until they switch, too?
Once the simple-modulation blowtorches are switched over the few remaining detectably-patterned signals will be soft voices crying in a wilderness of high-noise-floor. If we don't DELIBERATELY send some intended-to-be-noticed beacons we'll again be lost in the background - our own and the galaxy's.
A thousand years? In our case the detectability sphere looks to be only a tad over 100 years deep.
Don't blink!
Re:Solved? (Score:5, Funny)
Re:Solved? (Score:5, Informative)
(See this wiki article [wikipedia.org] as an example of a slightly technical description of why)
Re: (Score:3, Insightful)
Re:Solved? (Score:5, Interesting)
Maybe there really is no FTL, and other alien races are as leery of sending out giant seedships that they themselves can't ride in as we are, and are thus still hanging out in their home starsystem.
Maybe aliens are everywhere, aware of us, and simply choosing not to communicate.
Disproving aliens deductively is the opposite of science. The lack of easily obtained evidence for alien life is far from damning given the area that we are capable of observing with any real scrutiny.
Re: (Score:3, Insightful)
"other alien races are as leery of sending out giant seedships that they themselves can't ride in"
But for this argument to work, you have to believe that every alien race declines to send out automated self-replicators.
Re: (Score:3, Insightful)
Not at all. Think how many they'd have to send out. Think about the transit time, think about the number that would be lost. You can't really assume a straight geometric progression for something so incredibly fraught.
For a civilization to be able to keep up that level of commitment for as long as it would take would be inconceivable. This isn't to say that it couldn't happen, but it is to say that it's damn unlikely, even by the standards of the universe.
Re:Solved? (Score:5, Informative)
Think about the transit time, think about the number that would be lost. You can't really assume a straight geometric progression for something so incredibly fraught.
Well, almost, at least for the purposes of ballpark calculations.
Now, we have to make a couple of assumptions -- such as that they have the technology to send out self-replicators that will last long enough to get to the next star, which is a function of speed and durability. For the sake of argument, let's assume that the Voyager spacecraft (which just left the Solar System) are capable of self-replication, have a very long-lived power supply (long half-life radioisotope, for example) and their electronics will survive long exposure to galactic cosmic rays. (All big assumptions, but imaginably within range of our technology.)
Also assume an average spacing of about five light years apart for stars.
At the current speed (about 16 km/sec), it would take a Voyager about 90,000 years to reach the next start. Allow 10,000 years for the laborious process of self-replicating from raw materials and launching another of itself on its way, for a total of 100,000 years per generation. Assume each vehicle replicates itself only twice, and stays put (perhaps assembling large black monoliths on the local planets for the mystification of any eventual inhabitants). So we have a doubling rate of once per 0.1 million years.
Assume about 100 billion stars in our galaxy (this is the number I found most frequently mentioned), it would take between 36 and 37 doublings to send a probe to every star in the galaxy (less because stars are closer nearer the core). Call it 40 to allow for probe loss.
So in a mere four million years, self-replicating probes travelling no faster than Voyager could visit every star in the galaxy -- except for the speed problem. That growth rate can be maintained initially, but like any spreading colony (such as bacteria in a petri dish) the edge of the colony can only advance at a certain speed, and the doubling rate has to fall off (it's ludicrous to think that the number of visited stars could go from half the galaxy to the whole galaxy in a mere 100,000 years, the probes would have to be approaching lightspeed for that).
Take the galaxy diameter as 100,000 light years, it'd take nearly 2 billion years for a Voyager-speed probe to cross it, or near 3 billion to go around half the circumference (to avoid the black hole at the core). The galaxy is old enough that there probably sun-like stars (our Sun being a second-generation star, necessary if you want enough heavy elements for terrestrial planet formation) a couple of billion years older than ours. (And if we assume faster travel speed, say 0.01 c instead of 0.000055 c, the numbers get a lot better.)
So Fermi's question was simply "where are they?". If they're really not around (vs simply ignoring us or being undetectable to us), then the above assumptions are too optimistic.
Re: (Score:3, Funny)
"Damnit, can't those monkeys from the Sol system just shut up?"
"If we ignore them, they'll go away"
"They've been shooting radio waves at us for decades, I think we've established they aren't going away..."
Re: (Score:3, Interesting)
other alien races are as leery of sending out giant seedships that they themselves can't ride in as we are
I don't think humans are particularly leery of the idea of getting on a starship. And even if 99% of humans have no interest in getting on a starship, that leaves ~70 million perfectly willing volunteers. Give it another few hundred years of technological advancement and we'll be able to contemplate something large enough to be a "generation ship", or place the travellers in suspended animation, or some other trick to make the lengthy trip survivable.
Re:Solved? (Score:5, Insightful)
The point is you don't need to have a population that is astoundingly wedded to the idea of spreading out across the stars. You need a tiny, tiny fraction of the population to be wedded to the idea - just a handful of pioneering types who are okay with being placed in stasis for a few centuries, or raising their children and grandchildren inside a giant hollow cylinder. If you can find 500 people every few years who are willing to do something like the above, you will eventually become a pan-galactic civilization.
Cost (Score:5, Insightful)
Building a generation ship will easily be one of the most expensive and large-scale projects that our species has ever undertaken. A couple of willing colonists can't afford this alone. They need the entire population behind them.
Re: (Score:3, Insightful)
"Maybe aliens are everywhere, aware of us, and simply choosing not to communicate."
I think this is most likely.
To reach space you have lots of self-control so that you don't..uh..risk wiping out your civilization.
Once you reach that point of sophistication, you would feel that we humans are so damn annoying, unpredictable and of little use that you would want to avoid us at all cost.
That or we are an experiment they have been running for billion+ years and don't want to contaminate it. kinda like what we ea
Re: (Score:3, Funny)
I don't know why, but I keep having this dream about "six times seven", whatever that means.
No FTL (Score:4, Insightful)
>Maybe there really is no FTL, and other alien races are as leery of sending out giant
>seedships that they themselves can't ride in as we are, and are thus still hanging out in their home starsystem.
I'm sure I'm not alone in this, but I just had to say. If there really is no FTL, it is probably one of the most depressing aspects of existence.
Re:Solved? (Score:5, Insightful)
"Paradox solved, right?"
No. Some planets suitable for life have almost certainly existed in this galaxy for billions of years longer than the Earth. By now, one would expect there to have been civilisations that spread throughout the galaxy and therefore brought Earth within detection range of their signals...
But they would have to be within earth's range in the last 100 years or so for them to detect us. "Billions of years" means they could have existed on Venus before humanity ever showed up, for all we know. If they were that close, the signals would have long since passed us by at the point we were discovering fire.
Or they could have been reasonably nearby, but too far for the signal to reach us without fading out completely.
Or they could be using a different form of communication than we are able to perceive.
So, honestly, "expecting" anything is a little silly and assumes far too much.
Re:Solved? (Score:5, Interesting)
Assuming you can't skirt around the light barrier then that basically means sending small groups of people (or aliens or whatever) across trillions of miles, probably in some kind of hibernated state, in the hope that they'll bump into a habitable somewhere, set up shop, and begin to populate. Any returns on investment will be very intangible indeed- physical goods have to come back the same way they came (meaning it would have to be extraordinarily valuable to merit the shipping and handling on an interstellar ark) and information is cheap. You'd need to expect a very valuable treasure-trove of knowledge indeed for information to start making sense as an expected ROI.
I know many people just assume that interstellar travel is the "next step" in the development of societies but the longer I look at it the less it seems to offer tangible benefits for the people who have to invest in this.
I expect a society thinking in the long-term would obviously see the benefits of spreading one's seed across multiple star systems... but you have to postulate the existence of a society that takes the long view. Considering how easily a society as advanced as ours (not saying we're very advanced: just a society at the same level of advancement as us) is busily undermining its own biome, knows it's doing it, and doesn't care, and took pains to smother other societies which might have taken the longer view, I don't think we should expect many societies to reach the "long-view" stage before they wiped themselves out or got wiped out.
Re: (Score:3, Interesting)
That is a grotesquely 20th century view of interstellar colonization. It may or may not be on the edge of feasibility with fusion-based propulsion, it probably is with implausible anti-matter propulsion, but it's quite
Quantum Communication? (Score:3, Interesting)
Civilizations capable of greater levels of exploration would likely have developed means of utilizing communication along the lines of quantum information than our radio waves.
And I thought... (Score:5, Funny)
I thought it was because as they reach our level of civilisation, they built giant particle accelerators for research and turned their planets into black holes.
Re:And I thought... (Score:4, Funny)
So the monster black hole at the center of our Milky Way is really Trantor? GaLAXy!!
The First Ones (Score:5, Insightful)
Re:The First Ones (Score:5, Funny)
FIRST POST!
Re:The First Ones (Score:5, Insightful)
Maybe a zillion races have achieved the capability at roughly the same time, and are just more than 100 light years away from us.
What are the odds of anyone picking up our broadcast noise anyhow? It's not like we're aiming high wattage transmissions directly at likely stars, and with the transition to digital, our signal becomes even more ellusive (smaller spectrum footprint).
It's just as likely that other races only went through a brief period of wideband, and then switched to wired or line of sight optical or quantum bits or some crap we haven't even thought of yet.
The whole paradox is the height of hubris: aliens have to be like us, they have to advance along the same technological track, and they have to be broadcasting on a scale that we can easily pick up...We haven't cataloged every star yet, and that's an order of magnitude over any artificial broadcast we can understand.
Re: (Score:3, Insightful)
It's not like we're aiming high wattage transmissions directly at likely stars [....]
Actually, we have:
http://en.wikipedia.org/wiki/Arecibo_message [wikipedia.org]
It was a one-time occurrence, and the stars it was aimed at won't even be there when the message arrives.
However, Arecibo has also been used for Radar Astronomy [wikipedia.org], to map nearby planets. Those transmissions were probably powerful enough to detect outside our solar system.
Re:The First Ones (Score:4, Interesting)
Though it's possible we are the first, it's as likely as winning the lottery. Someone has to do it but the chance of that someone being you is so small that you should first rule out other, more plausible, scenarios.
My favorite is that only the paranoid survive. Civilizations that learn to communicate quietly are the ones that survive. Broadcasting your existence is a great way of advertising 'livable real estate here!' and inviting other civilizations over for a look see. Not too smart if it turns out they end up wanting your planet.
But if that's right... (Score:5, Insightful)
Re: (Score:3, Interesting)
I posted this in January 2005:
Drakes formula allows some kind of estimate as to the number of intelligent societies there might be "out there".
The following is from a great book by A.K. Dewdney: Yes, We Have no Neutrons.
The formula is N = R* x Fp x Ne x Fl x Fi x Fc x L
For which:
R* = number of new stars that form in our galaxy each year
Fp = fraction of stars having planetary systems
Ne = average number of life-supporting planets per star
Fl = fraction of those planets on which life develops
Fi = fraction of li
God I hate Fermi's Paradox. (Score:5, Insightful)
This is hardly a new idea. It's so not new that I think I remember saying something similar about two years ago [slashdot.org], and I'm not exactly an expert.
Analog signals degrade quickly, and digital signals are worse, in their way, because they don't tolerate degrading as well. Couple that with broadcast limitations imposed by local governments to keep signal strength down, and I can't see how our signal could be reliably detected more than a few light years away without a HUGE radio antenna array.
Is the author even familiar with the Fermi Paradox (Score:3, Insightful)
The scope of the Fermi Paradox deals with the length of time it would take an intelligent civilization to explore and colonize the galaxy, and given Fermi's estimates we should have observed spacecraft and/or probes. SETI's signal hunting doesn't even scratch the surface of the paradox.
There is no mystery here... (Score:3, Funny)
only humans think in this way (Score:5, Funny)
We humans are still a bunch of young, angsty teenagers. We desperately want to make the "first contact", crying and yelling and suffering from the depressive thought of loneliness.
Other galactic civilizations simply matured and stopped worrying about such pointless things. They make themselves busy with real business.
Grow up, humans.
Communcations (Score:3, Insightful)
Mistake in summary (Score:3, Interesting)
intellgient life... (Score:3, Interesting)
Suppose intelligent life was a super freakish accident, not a forgone conclusion. It took 4-billion years for it to develop on earth. I'll bet it might easily have never happened. And then, there was no reason why we had to develop a technology based culture. That, in itself, might have been a freakish cultural event.
So, maybe, we are pretty special after all.
Re:intellgient life... (Score:4, Interesting)
Except that intelligence doesn't necessarily take 4 billion years to evolve. It's not a nice, clean timeline. The real hurdles were evolutionary events like the spark of life, sexual reproduction (leading to more mutations), and multi-celled organisms. Evolution, through nature's nasty tendency to wipe the slate clean, has to keep taking steps backwards. Dinosaurs lost their place on top of the heap after 100s of millions of years of dominance and 65 million years later we have intelligent life.
Imagine if there are worlds where there are fewer extinction level events or environmental factors that favor jumping the hurdles sooner. We just don't know enough about other planets to know how long it takes for intelligence to evolve.
Re:intellgient life... (Score:4, Interesting)
Good points, to which I want to add, that intelligence does not necessarily lead to radio waves at any eventual point.
Radiowaves are a social phenomenon. They are used to communicate between beings of shared language over large distances in short amounts of time. This means that there is a need to communicate quickly, and natural methods are insufficient. For example, whales are intelligent and communicate over great distances. Yet they have no need for radios because the water medium is good enough for their needs.
Animals are capable of using magnetism to coordinate. Be it distance migrations or short-distance homing. Avian/IP takes this into consideration. If they found a way to communicate naturally via the magnetic material in their heads (over short distances - telepathy) they could pony express a message throughout their habitat at relatively low time cost.
Then even if they had the motivation or understanding they still need to be physiologically equipped to construct a device. And that device needs mining and metal refining technologies.
So while there may me the means, there may not be the motivation for the mega an giga-watt broadcasts we currently use.
I expect that if we ever get exploring other habitable worlds, we'll find a lot of life to interact with in complex ways, but are technologically inferior due to physiology. I call this the "cephalopod argument". That is, they seem to be relatively intelligent creatures, while sharing little to nothing in common with our nervous system. They've been unchanged for millions of years, without additional evolutionary selection criteria, they have no reason to change. (Also, until we can communicate with them we are unlikely to be able to communicate with ETs unless they provide the means)
Lots of other reasons, too... (Score:5, Insightful)
Unless it's been vastly misrepresented in mainstream presentation (like TFS), Fermi's Paradox sounds pretty ridiculously simplistic.
Other bad assumptions it makes, just off the top of my head:
1. Other intelligent civilizations want to engage communications with aliens who, for all they know, might try to blow them up or eat them.
2. Those civilizations are willing to spend resources to beam electromagnetic radiation out into space in the vague hope of someone noticing.
3. Other intelligent civilizations "capable" of "communication" will follow the same technological arc as us and develop electromagnetic communications rather than, say, quantum communications or something we haven't even thought of yet.
4. Those aliens will assume that WE (or some unknown aliens) will be listening carefully for extrasolar broadcasts.
5. Those aliens even have a concept of "communication" and aren't just some hive-mind that never needed to evolve social skills.
6. They didn't cut their Alien-SETI funding to pay for medical research or an Alien-Wall-Street bailout package or something. (I mean, what do you think the chances are that WE will broadcast for a thousand years?)
And so on.
Really, Fermi's Paradox sounds like me saying that if I sit on a lonely beach for a week and don't find a bottle with a message in it in proper English, there are no other intelligent beings in the world.
Middle of nowhere (Score:5, Funny)
It's not like we're located close to Downtown Galaxy. We live out on the edge. There's probably some galactic equivalent of AT&T or Comcast that is telling everyone else "We'll be providing them with service 'soon'. So our monopoly is justified."
Either that or the installer showed up and we were too busy/unaware to answer the door. So they said they'd be back later.
Where is everybody? (Score:4, Insightful)
Extraterrestrial life may become a boring topic (Score:3, Interesting)
I always thought SETI was a fools errand (Score:3, Insightful)
From a layman's perspective, I don't see how they could reasonably hope to see anything, especially if the aliens are like us and tend to direct their transmitted energy rather tightly to avoid wasting too much of it.
Lets say for instance that we can pick up a signal from Geosync Earth orbit using little more than a crappy whip antenna (See: Satellite radio) for a system with maybe 200dB gain in total. Now lets say we're looking for ET with a magical system that has a million dB worth of gain. The distance from the Earth to a Geo satellite is 26,200 miles. The distance from the Earth to Alpha Centauri is 2.57 Ã-- 10^13 miles. Just comparing the square of the distances (6.86 x 10^6 to 6.5536 Ã-- 10^26), you can see that a gain of 10^9 is just not going to cut it, not by a long shot.
It seems to me that the only way SETI could possibly work is if ET was narrow beaming an extremely powerful signal directly at Earth 24/7 for centuries, or if they were hanging out in orbit chatting away over CB radios in stealth spaceships. The most plausible reason why SETI has not found anything is that any signals that are out there are well below are detection threshold, and this is even before we begin to think about a civilization that moves beyond RF transmissions in favor of something more exotic (entangled photon radios?).
Keep in mind (Score:3, Insightful)
Note the following:
1) Author is an MBA. The "Bouchet-Franklin Institute" is his private lab.
2) The place of publication, arXiv, while very useful in certain fields of physics, is not peer-reviewed. It's basically the same as posting this paper on your blog.
3) The arXivblog, not run by any people actually associated with arXiv (as far as I can tell) regularly posts completely inaccurate summaries.
4) The published paper is laughably simplistic. As others have pointed out, these are obvious considerations, and the paper is mostly argument and simple geometry. While it's nice to see some back-of-the-envelope calculations on a minimum civilization density for a given detection cutoff, that's exactly what this is -- back-of-the-envelope calculations.
Intelligence out there!? (Score:3, Funny)
Hell, man! Is there any intelligence down HERE!!
Jeesh! These scientist with all their assumptions and preconceptions. Last week, we were supposed to believe that because we're able to capture a few pixels of UV radiation from a distant star system, and it can be spun into a computer model of the planet's atmosphere. The whole thing is a bunch of naval gazing to keep a bunch of nerds a colleges employed. Get a job, guys.
Re:300 isnt teeming with life (Score:5, Informative)
Re: (Score:3, Interesting)
Imagine holding up a lit LED on top of Mt Everest. How far away do you think you'd be able to see that, even assuming clear viewing conditions.
Now back off and imagine how far away our sun would be easily distinguishable from every other star in the milky way. The closest neighboring star to us isn't even the brightest star in our sky.
Compared to our sun, all of our communications are on the level of that LED on Everest. That will give you an idea of the likelihood of spotting a signal from any distance, ev
Re:Hello, (Score:5, Funny)
Hello (hello, hello)
Is there anybody in there?
Just nod if you can hear me
Is there anyone home?
Do we want to be found? (Score:4, Interesting)
Why are we soooo certain that we *want* to be found? I personally would prefer not to be a slave or a menu item to another race of beings. Honestly, what makes you think they will be peaceful or even tolerant of our existence if do find another civilization?
2 cents,
QueenB
Re:Do we want to be found? (Score:4, Interesting)
Or to put it in terms of Fermi's paradox: Maybe the galaxy's other 5000 intelligent civilizations are all keeping quiet because they know what's out there -- and it ain't friendly.
Maybe we're an entire civilization of stupid newbs wandering naked and lonely in a forest full of predators, shouting "Heloooo! Anyone home?"
Re:Do we want to be found? (Score:5, Insightful)
...Why are we soooo certain that we *want* to be found?...
Anybody intelligent enough to be able to travel throughout this galaxy or beyond, or even just communicate, would certainly study us for awhile. They would have learned by now that we humans are a warlike race that cannot get along with one another even on our own world. Even in our fictionalized scenarios, with imagined technology, such as Star Trek or Star Wars, there is nothing but war and death, such as the destruction of entire planets by some of our imagined technology. Human history provides an absolute guarantee, that if we would meet such an advanced civilization, we would use their technology against them and one another.
Re:Do we want to be found? (Score:4, Insightful)
Anybody intelligent enough to be able to travel throughout this galaxy or beyond, or even just communicate, would certainly study us for awhile. They would have learned by now that we humans are a warlike race that cannot get along with one another even on our own world. Even in our fictionalized scenarios, with imagined technology, such as Star Trek or Star Wars, there is nothing but war and death, such as the destruction of entire planets by some of our imagined technology. Human history provides an absolute guarantee, that if we would meet such an advanced civilization, we would use their technology against them and one another.
Typical that some guilt ridden touchy feely sentiment gets modded insightful here.
The entire premise that some advanced civilization would evaluate humanity on it's ability to get along is ludicrous. Wasn't that the whole storyline of the Q in TNG?
If we are going to start asserting crap like this, then it would be equally valid to suggest that we are the equivalent of the 98 lb. freshman nerd of the universe and that we've been stuffed in our own locker. How about that instead of our galactic neighbors being worried about our 'warlike' nature we have been shunned for being a bunch of weak ass little pussies? Maybe they are just waiting for us to sort out our little squabbles so they can deal with the one with big enough balls to kick the crap out of everyone else. There is NO basis to suggest that either of these scenarios are more or less likely.
I'll buy just about ANY technological explanation before you'll convince me that we are being left alone because some advanced civilization who can hear our signal is essentially scared of dealing with us. Honestly, the suggestion itself is the height of conceit.
Re:Do we want to be found? (Score:5, Insightful)
The flip side of this argument is that a species comes to dominance over its own planet through competitive behavior, i.e. aggression. Just because they have superior technology doesn't make them morally superior.
As for what we have to offer? There are a plethora of movies that spell this out: natural resources, a habitable planet, an enslavable population. What do you think our own warlike, inferior race would do if, say, Mars were humanly inhabitable tomorrow? Crossing the ocean in the 1500s to settle the New World was a scary proposition, and yet the Europeans didn't let that stop them. It was precisely their ambition, competition with their neighbors, and their desire to claim the wealth of those new lands that drove them to do it, even with primitive technology.
Peaceful races may fail to contact us not because of their moral superiority, but because they lack the incentive to bother.
Re:Hello, (Score:4, Funny)
I think you mean to say "Poems? The lad fancies himself a poet!"
Re: (Score:3, Informative)
He did [lyricsfreak.com].
Re: (Score:3, Interesting)
Sure it is. It's just not a good one.
Re: (Score:3, Funny)
Re:I like choice B (Score:4, Insightful)
Send me $1,000. I guarantee you there is a 0.000000000001% chance that I will send you back $1,000,000. Of course, if you don't send me the money, the odds of me paying you are zero. So you should definitely send me the money.