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New Paper Offers Additional Reasoning for Fermi's Paradox
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?"
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.
Maybe we are the first to achieve this capability. If life did create itself from a universe that created itself, ONE of the life forms which achieved this interstellar communication would have to be first. Why not us?
...it means that civilizations that spread out and last longer than 1K years are exceedingly rare. Which would mean that our odds of achieving any meaningful interstellar travel are quite low. (We might make a space probe or two, but like how we got to the moon but haven't done anything with it, apparently nobody puts out space colonies.) There are other posible theories, though.
PHEM - party like it's 1997-2003!
Did you read the summary? The point is that outside of our galaxy no intelligible signal is going to reach us. Therefore, the rest of the universe doesn't even enter into it.
You are using English. Please learn the difference between loose and lose; they're, there, and their; your and you're.
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.
Colorless green Cthulhu waits dreaming furiously.
Exactly. Maybe all those "crazy" people are actually talking to aliens.
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.
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.
He's getting rather old, but he's a good mouse.
I, for one, found his ideas intriguing and wish to subscribe to his newsletter.
Not necessarily. It may just be that interstellar travel isn't feasible, the ardent wishes of sci-fi writers everywhere notwithstanding. Remember, it's never enough to simply be able to do something: it has to make economic sense if you expect to get anybody else on board, too.
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.
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
I understand your reluctance, after all you're the one who posted:
http://slashdot.org/comments.pl?sid=1112493&cid=26694469
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.
Hence, gamma-ray bursts. The advanced-technology equivalent of flaming laptop batteries.
Welcome to the Panopticon. Used to be a prison, now it's your home.
I've never understood why Christians are so afraid of finding life on other planets or why atheists are so adamant that it will prove the Christians wrong. The Bible doesn't say anywhere that there is only life on Earth. If you take the creation story in Genesis metaphorically (lots of Christians do), then life evolving on other planets doesn't clash with theology at all; unless of course I'm totally missing something, in which case please point it out because I'm curious. From what I see, religion and science aren't necessarily incompatible.
Hello (hello, hello)
Is there anybody in there?
Just nod if you can hear me
Is there anyone home?
When calculating astrological signs over timescales of millenia, don't forget that due to precession of the Earth's axis the signs all shift by about a month every 2,000 years. So today's Libra is the year 4000's Virgo.
(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.
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!
Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way
The 1,000 years isn't time from broadcasting to die-off. It is time from broadcasting to narrowcasting (using lasers or some other communications method that directly targets the intended receiver). Once narrowcasting is in use, we wouldn't expect to hear them unless they know we are here and are specifically targetting us.
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.
Find environmentally and socially responsible products on http://buy-right.net
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.
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.
Blasphemy is a human right. Blasphemophobia kills.
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.
Contribute to civilization: ari.aynrand.org/donate
...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.
All theory is gray
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.