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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?"
One of the thoughts that's crossed my mind as we further explore and understand utilization of quantum information is that if there is sentient beings "Out There" with some level of capability for space exploration is that it would seem that this would be a very likely way for them to maintain communication. Efforts such as SETI would then be attempting to discover background noise (I use the term "noise" here more as commentary on what most of what we communicate tends to be) of civilizations no more advanced than ourselves attempting only very nearby levels of communication.
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 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).
Fascism starts when the efficiency of the government becomes more important than the rights of the people.
Summary says: "300 communicating civilizations in the Milky Way". The quote is: "300 communicating civilization in the galactic neighborhood". I interpret the latter to mean all solar systems within 1,000 light years. The former quote leads to the entire milky way, which has a diameter of 100,000 light years.
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.
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.
ad logicam Claiming a proposition is false because it was presented as the conclusion of a fallacious argument.
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.
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.
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.
He's getting rather old, but he's a good mouse.
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 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 life forms that become intelligent
Fc = fraction of intelligent beings that develop radio
L = average lifetime of a communicating society
The formula has appeared in several popular science magazines with the values set to:
N = 10 x 1 x 1 x 1 x 0.01 x 0.1 x L
So, N = 0.01 x L
The only numbers in the formula which anything other than a guess can be made are R* and L. Based on current observations most set R* at 10. Everything else in the formula would be a wild guess, except for L. More is known about L than any other part of the formula, since we are a communication society. Since we receive more and more of our communication from satellites, cable, and the internet, we are broadcasting less and less away from the earth. In the near future we will likely go dark as a significant source of radio/broadcast signals capable of being detected from space. If we say that our source of signals is about 100 years, drop the 100 back into the formula and you get 1. That must be us.
Not only the Pope, but also several prominent Protestants have discussed the issue, including the venerable C. S. Lewis, who wrote an entire series (the "Space Trilogy") exploring the possibility. He uses philosophy throughout and though short, it has some pretty dense ideas. As a Protestant myself, I see no problem with an infinitely powerful God creating whatever he felt like in whatever length of time he chose to do so--this includes aliens. I very much doubt Christians would be all that disturbed about except for the ones that give most of us a bad name by making it on the news for shooting someone.
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
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
HDGary secures my bank
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.
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.
Where is that guy who'd die defending what I had to say when I need him?
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'
-Michael
We may not be able to translate dolphin language, but we can tell it contains non-entropic information. In other words, we can at least tell that they have a language.
Information theory can tell us whether or not there's a message in the data, with a fairly high probability. That doesn't mean we can transcribe it.
My guess is that loud radio waves are a primitive form of communication. We already know that we can transmit information in better ways, and use the spectrum in better ways, and use less power to boot.
We just haven't done it. We're like a 16 year old kid barreling down the highway with the windows down and the music all the way up. I don't think it's very good security, really. It's basically security through obscurity for Earth. We're too far away for it to matter, we guess .
A sufficiently advanced civilization probably knows better, and has probes out here sending back quantum entangled messages instantly, about our local shit. At least, that's what I'd do, and I'm just a monkey.