The Fermi Paradox is Back 713
nettxzl writes ""Sentient Developments revisits the Fermi Paradox which is "the contradictory and counter-intuitive observation that we have yet to see any evidence for the existence of Extra Terrestrial Intelligence (ETI) although the size and age of the Universe suggests that many technologically advanced ETI's ought to exist." Sentient Development's blog post on the Fermi Paradox states that "a number of inter-disciplinary breakthroughs and insights have contributed to the Fermi Paradox gaining credence as an unsolved scientific problem" Amongst these are "(1)Improved quantification and conceptualization of our cosmological environment, (2) Improved understanding of planet formation, composition and the presence of habitable zones, (3) The discovery of extrasolar planets, (4) Confirmation of the rapid origination of life on Earth (5) Growing legitimacy of panspermia theories" and more ... So, where is everyone?"
Have some patience, we'll run across them... event (Score:5, Insightful)
In the immortal words of Douglas Adams, "Space is big. You just won't believe how vastly, hugely, mind-boggingly big it is. I mean, you may think it's a long way down the road to the chemist, but that's just peanuts to space."
The problem isn't that there isn't anyone else out there. With so many billions of stars and planets, the odds that there are other intelligent beings out there are astronomically large. (Pun slightly intended.) The problem is that the distances required to travel to reach them and also astronomically large, and the odds that there is life on any given planet are infinitesimally small.
I always put this thought experiment before people: If you had a spaceship that could instantly take you to anywhere in the universe, where would you go?
Sure, you'd probably drop by a few nebulae and stars and even planets, but after you've seen a few, where to then? You could travel to other planets for lifetimes and still not run across intelligent life on other planets. It's not that truly interesting things aren't out there, it's just that the universe isn't very conducive to producing life-bearing planets. Sure, with so vastly many planets, it will happen (and obviously has), but finding life out there is like finding a needle in a haystack, and we're just now starting to be able to see the haystack.
Further complicating matters is that we don't have spaceships that can instantly take us anywhere in the universe, and according to the laws of physics as we know them, it's likely that other intelligent beings don't either. Maybe they have travelled lifetimes and they just haven't run across us yet.
So be patient, my fellow humans, it may take a few million (or even billion) more years. After all, it's more than just a trip down the road to the chemist, and something that cool will probably be worth the wait.
Time to give up... (Score:3, Insightful)
Considering the state of terrestrial intelligence, maybe any ETIs have realized that broadcasting attack coordinates into space may not be such a great idea?
Maybe we're better off alone (Score:5, Insightful)
Maybe we should be glad if we're too insignificant to be noticed just yet. (We certainly don't have our act together, at any rate.)
not really a paradox (Score:1, Insightful)
Re:Have some patience, we'll run across them... ev (Score:2, Insightful)
The paradox (Score:2, Insightful)
IMHO a simple way to resolve the paradox is that no species has the raw material or the scientific knowledge to ever send self reproducing probe to explore the galaxy. We might not be alone but we will never meet each other and stay in our small island of life.
Maybe they always quickly blow themselves up? (Score:4, Insightful)
We can get humans to the moon, but not to the next planet.
The universe is vast even compared to our oceans and we lose people in our oceans all the time. Why would we think a space probe would be noticed by someone?
Now, our technology will improve and some of the above statements may change rapidly. But, the chances of our using some of those technologies to destroy ourselves seem to be accelerating as well. Perhaps the missing part of the model is that other civilizations always blow themselves up within a few hundred years of their first communication attempts or steps off their planets.
We probably will.
The universe is way too big (Score:1, Insightful)
CSI quote (Score:3, Insightful)
Better Off. (Score:5, Insightful)
We're technologically advanced over all the other creatures here on Earth. We eat them.
--
BMO
simple answer (Score:1, Insightful)
Radio waves.. (Score:5, Insightful)
My view though...
Our civilization is in its technological infancy, and even we find radio rather slow and limiting. I can't imagine us leaving much of a radio footprint in another hundred years, especially not leaking it with omnidirectional broadcasting.
Imagining the same being the case of another civilization, we're trying to listen in on broadcasts from a time window of two hundred years or so, and we've been listening for a couple of decades. In a context where being off by a million years wouldn't be too bad, the odds strike me as fairly infinitesimal even if assuming thousands of civilizations located cosmically nearby.
Doesn't hurt to try, mind. It's not like we have a lot of other options open to us currently.
Re:Have some patience, we'll run across them... ev (Score:3, Insightful)
Now, think of it in a new way. Suppose you were a civilization that just developed space travel, much like where we are now. You have a galaxy around you with 400 billion stars, and that's a lot. It takes you 100,000 years at light speed to cross the galaxy, and that's a long time. However, you have 2 billion years to explore. I have no good grasp on where humans will be 2 billion years from now, but I am sure we will be pretty advanced. Now add to the mix that there are maybe 1000 or 10,000 or 100,000 other advanced civilizations alongside with you, and you can see why we are wondering where everyone is. Oh, and there are a trillion or so other galaxies out there, so if you start to consider the possibility of intergalactice travel, you can even go futher with this.
Really the best answer to the Fermi paradox is that Earth-like conditions are rare. However, I think we just discovered a planet 20 light years away that has 0-40 degreee celsius temperature, water, and is a rocky planet, so maybe that is not the answer either.
A self made Paradox (Score:4, Insightful)
Possible reason why we don't see their TV shows... (Score:4, Insightful)
At this point in time TV and radio is rapidly being usurped by interactive media, most of which currently travels along cables and would of course be undetectable from other planets. As for wireless internet, the power of a wireless LAN router is obviously far less strong than say a TV signal broadcast from a TV tower. And future wireless broadband signals would presumably also be local and low-powered, because it's more efficient that way. (Guesswork, of course).
Of course traditional high-powered TV and radio broadcasts aren't dead yet, but in say 100 years it's pretty easy to imagine that they they might be. (Or not -- I know this is all speculation)
So, IF (huge if) other civilisations follwed this path, this might be a possible reason why we don't see or hear their broadcasts -- because like us their high-powered broadcast media only existed for a short time, and were soon replaced by more efficient low-powered interactive media
All wildly speculative I know.
Re:Evidence for intelligent life (Score:3, Insightful)
Would we bother to communicate with ants? We might observe them, kidnap a few for experiments, but we don't really bother to send signals at them.
Evolution may suggest they will not be pacifists (Score:3, Insightful)
Why would showing restraint with respect to interactions with your own species mean you would show similar restraint when interacting with other species? Wolves can show much restraint to other wolves, but little to other species.
Evolution favors a combination of aggressiveness and intelligence. Losing either quality will make you vulnerable to those who have not lost either. Consider pacifism. Pacifism only works when isolated or when there are non-pacifists who protect the pacifists. Humans are probably either unique or one of many intelligent species. Given many intelligent species, some may have become pacifist in isolation, but all will not. Those who retain some aggression will dominate in the long term. The more civilizations that have made contact, the less likely we are to meet pacifists. Given that our first contact is also likely to be one of many I'd so the odds of your optimistic scenario are not good.
Re:"something wrong with our thinking" (Score:3, Insightful)
A civilization that survives long enough to reach the technological level necessary for interstellar spaceflight will have stabilized its population and learned how to use local resources to make their home world a paradise. Why go anywhere else? The expense is enormous, the payoff non-existent.
That statement boggles the mind. You're assuming, from a human context, that no living thing in the ENTIRE UNIVERSE would EVER want to engage in space travel. Head swollen a bit?
For that matter, you assume that all livings beings in the universe must be located on "worlds." What about a space-dwelling species that inhabits the nebula of a supernova, feeding off the remnant energy and matter? Such a being could be planetary in size, itself. Are you suggesting that such beings should never want to leave their home nebula?
Who the hell are you anyway, to tell all the species which may inhabit the universe, what to do?
But sure, I guess from a naive Star Trek sort of viewpoint where the only relevant species out there are humanoid and pretty much exactly like us, your madness makes sense.
Re:The paradox (Score:5, Insightful)
I was talking about this with a coworker a few weeks back and realized something. Back when radio was first discovered they used *huge* transmitters to transmit a small amount of data a short distance because their receivers were so crude. Later receivers were vastly improved and you could use much lower power to send much more data. Soon we had over the air TV that had a phenomenal amount of data flowing through the air, but, to not encroach on competing channels in adjacent areas, the signal strength was reduced again.
Skip forward to today and we are using cable (very little "signal" escapes) and fiber-optics (no signal escapes) to send even more data back and forth. So, in a few years time we've gone from a very noisy planet with out much to say, to a much less noisy planet with much more to say.
I think it is inevitable, simply from an efficiency perspective, that we will be using more and more "tight-band" communication methods in the future (quantum entanglement?). It seems intuitive that the more advanced a civilization gets the more efficient it will strive to be. The more efficient it is, the less noise will be wasted into space (especially compared to the natural noises of the planet, like lightning, aurora, etc.)
Look how much more efficient we've become in just a hundred years. If this is indicative of other civilizations, then the window of opportunity for eavesdropping on them is extremely small. And that's assuming that they are remotely like us and not building their civilization at the bottom of their ocean or are just so different from us that we wouldn't even recognize them as life.
As far as colonizing the stars goes, barring some way of FTL (or instant) travel and communication, I think we will never move beyond our own solar system in our current physical form. I think we will have figured out how to lose our bodies and move our consciousness into "the machine" before then. Once that happens, there will be no need for maintaining the human race in a biological form at all since "reproduction" can occur in solid-state. Once we've reached that stage, being effectively immortal, we might be willing to entertain the thought of physically traveling to other stars, but there will be no need to colonize them, they can be virtualized. But then again, we could virtualize the whole trip anyway.
Either way, that step in technology would almost guarantee a very efficient system that would need to produce almost no waste products. With no need for maintaining and supporting physical bodies, all of the energy required to sustain physical life will not be needed. No more growing and shipping crops. No more energy wasted in physical travel. In fact, very little need for ever physically moving anything, from then on. This would make most of our civilization a "static" construct. At that point, unless we were purposely broadcasting for neighbors, who'd ever hear us?
Wrong question (Score:3, Insightful)
Why *not* go anywhere else?
First, there's a danger in keeping all your genetic eggs in one basket. Secondly, I don't know about you, but I have a strong yen to stride among the stars. I do know there are many like me. Why climb everest? Why colonize the moon? Or Mars? Why *not* travel to the far reaches of the universe?
Humans are, by and large, creatures with a great curiosity. In the face of a utopia, I'd hope that at least some would wish to explore, and perhaps settle, the great unknown.
Re:Have some patience, we'll run across them... ev (Score:5, Insightful)
What an extremely narrow and self-centered view of the universe.
First of all "extremely improbable" when talking about something the size of the universe means that even if life in a given star system had a 1 in 1 million chance of ever developing (I'd call that "extremely improbable"), that's still 5,000 systems in our galaxy alone that will develop life someday, or already have. For a 1 in 1 billion chance, that's still 500 star systems. And there are up to 500 billion galaxies in the universe. Even if only 1 out of every billion star systems will support life - or perhaps 1 out of every 5 billion planets - that would still mean there could be trillions of life-supporting star systems in the universe. Given that there are not one, but two planets in our system that are capable of supporting life (Earth and Mars), both of which may have actually supported life, it's certainly no stretch to think there are at least this many planets out there that could support life and that at least some of them are actually doing so.
It's all too easy to draw conclusions for the entire universe based on observations of your local area. People do it not just when thinking of extra terrestrials but even when thinking of other people and cultures on our own planet. There's a tendency to think that the way we do things is just the way that things should be done. But there are many ways life can develop, many ways life can be supported, and many, many planets that are much too far away for us to observe or for them to observe us. It's foolish to think that we are alone simply because we have not observed any other intelligent life in the few hundred years we've been looking.
Maybe other life forms have sent out self replicating probes. Why would we have necessarily noticed?
Re:Advanced Intelligence May Just Be Embarrassed (Score:3, Insightful)
I don't see why they would be embarrassed. When a baby craps in his pants, are you embarassed for the baby? When you see dogs marking their territories with pee, and humping human legs, are you embarrassed about the dog? Rabbits puke their partially digested food, and eats it again. Cows do the same, but unlike rabbits, the food never exits their mouth. Fleas puts their eggs in horse-shit. Are you embarrassed about that? When you see a blue-green algae in the microscope using it's flagella to swim towards the light, are you embarrassed about their primitive behaviour? That humans broadcast infomercials, reality TV, and porn, would to aliens be just as embarassing to them, as it is to us that salmons have to go up the same river as they were born, to lay their eggs.
Lets assume the aliens are one or more singularity leaps beyond us. They may not even realize the distinction in "intelligence" between us and a lobster as anything significant (just like we rarely bother to distinguish between the "intelligence" of a lobster and a tuna). Our cars and planes and computers is surely a fascinating example of an extended phenotype [wikipedia.org], but it doesn't really tell them that we are intelligent, does it? Even if they are able to observe that we have a primitive auditory and visual communication system, it will to them be as unevolved as ants exchanging pheromones to communicate. There is no way they would be able to exchange ideas with us, even if they mastered our language perfectly.
Fermi's Paradox = Fermi's Blunder (Score:5, Insightful)
This is one of the most likely reasons we've not "seen" anything as yet. As far as we know, interstellar travel is annoyingly slow and energy intensive; that alone could account for no visitors, no matter how well populated the universe is with intelligent beings. That leaves communications; but our experience here indicates that catching the communications of others is very unlikely. Why? Well, we've been hanging about for 50,000 years or so in the form we like to consider actually "us." Of that 50,000 years, we've been using radio and television for about 100 years now. But in the last 25 years, more and more of our radio and television signals have been finding their way into satellite to ground signals, which do not radiate away from the planet and are very, very low power; other signals are now traveling inside cables instead of the through the air; and finally, newer communications are moving to optical methods, and we're talking optical in cables for the most part, meaning again, less and less high powered "accidental" signal radiation (effectively zero in terms of interstellar distances.) The reasons are higher bandwidth, vastly more communications channels, more energy efficient, better control over where the signal goes - and doesn't go. These are reasons that transcend our civilization; there is every reason to think that other beings would find the same benefits.
Next, look at our development: We're paranoid. We have been prey for a lot of living things ranging from other people to lions to snakes to spiders to bacteria, consequently we're not of the mind that the universe is likely to be a friendly playground. You can find reactions to that notion everywhere from science fiction to the unwillingness of today's moms to let their kids play outdoors unsupervised. Looking at our SETI program, the first thing you probably notice is that we're listening (poorly), which seems prudent; but we are not intentionally transmitting a signal to the stars, which has been a political decision. That leaves the accidental radiation, the strongest of which has been radar transmissions, which are mostly information free... but even if they're enough to get us noticed, we've only been at this for a 100 years, so our signals are only 100 light-years out so far. That severely reduces the number of potential listeners, and of course it presumes they, like us, are listening for anything, not just signals modulated with complex information.
Also, as an earlier poster observed with a quote from Douglas Adams, the universe is gi-flipping-normous.
All of this contributes to why Fermi's Paradox should be considered Fermi's Blunder by anyone who really thinks this through.
I see no reason to doubt there are plenty of other life-bearing planets out there, and that a fairly significant number of those in turn have intelligent life of one form or another. The fact that we've not "heard" any of them doesn't surprise me one little bit, Fermi's naive reasoning aside. In another 100 years, the odds of us radiating anything at all from our little corner of the universe are probably very low indeed. If that's typical (and it may be longer than typical), then in order to "catch" someone else transmitting by accident, we'll have to be listening at the same time + distance in light years that they go through the RF development process, and we'll have to have sensitive enough equipment to hear them. That last point is interesting, because although technically speaking, we are listening for "them", we're presuming they're sending at the low-noise point of the spectrum with the intent of us hearing them. If it was accidental radiation like radio and TV we were looking for, we couldn't hear that with our current gear at all. In order to get to that level of sensitivity, we'll need outer space "ears", and pretty big ones. Nothing like that is even on the drawing boards. So again, the odds of us hearing anyo
Re:We're right here (Score:4, Insightful)
Or at the risk of being "Richard Rank" from Contact, maybe they've solved those problems and yet they still like killing other civilizations just for the sheer joy of it. Vikings were filthy rich at one point in history, and had everything they could possibly want (or could get it just by making threats), and yet that didn't stop them from slaughtering others and themselves on a regular basis. Who even knows? It's so hypothetical, we can't even speculate.
Why take the trouble to scrap it up with a pestilent life form at the bottom of a steep gravity well when mass and energy are abundant in the oort cloud and asteroid belt free for the taking?
1) Because you're fighting for some reason other than lack of resources. As another example, look at the planet Krikket in the last couple books in the Hitchhiker's Guide. They seemed to have everything they wanted, and yet they still engaged in a campaign to destroy everybody else just so they could be alone in the universe. True, it's a comedy, but you're making a lot of assumptions about the nature of conflict here that don't necessarily hold true.
I do agree with you that the V scenario, where the aliens come to steal food and water, is pretty stupid.
2) There's energy in the Oort Cloud? I thought it was just a bit of dust flying around.
Why travel all the way to another star just for that since those things are doubtless abundant where you came from?
Because the resource "people to kill" may not be abundant where they come from.
The real point is that we simply don't know the answer to any of this. ETs could be so different from us that we don't even recognize them (maybe we've already had contact, but they move so slow that we didn't notice.) They could have motivations entirely different than any that apply to us.
Re:The paradox (Score:1, Insightful)
Re:Not a few generations - 20 years (Score:1, Insightful)
Heck, as long as you have basic literacy and the ability to think critically, along with the ability to share information freely, you could probably advance technology quite quickly. The bottleneck to technological improvement would no longer be the speed of research, but rather the infrastructure for exploitation of natural resources.
Re:We're right here (Score:3, Insightful)
Should be lots of deuterium there.
Cellular beginnings... (Score:5, Insightful)
The earliest cell-like containers may well have been simply lipid (fatty) bubbles that presented a semi-permiable membrane that let certain chemicals thru. These types of lipid bubble could easily have formed naturally (think froth at the edge of the ocean), maybe even based on products of these chemical reactions. There's no need for the earliest "cells" to have been created/encoded by the chemicals they contained as they are today (DNA).
The earliest forms of replication also need not have been self-encoded - they would almost certainly have been due to physical processes - e.g. if you whipped up (sea-shore wave action) a bunch of large fatty bubbles, you'd get a lot of smaller fatty bubbles which would then "grow" via their semi-permiable enclosure letting in the external chemical components that "fed" the chemical reactions. Similar to how an amoeba )modern single cellular organism) "reproduces" by splitting into two.
Highly complex chemicals like DNA or RNA may have have originated as simple chemical catalysts that sped up the reaction process - i.e. guided it rather than being part of it per se.
These types of extremely simple pre-cellular origins are far from being low probabiliy events - they are alomost inevitably going to occur given a rich enouch chemical environment and suitable phyiscal conditions (water, wave action = stirring, lightening, sunlight, etc). If you're interested in the beginning of life at this extrememly early stage, try reading Stuart Kauffman's "At Home in the Universe".
Even at this early stage, evolution would necessarily have occured. Among multiple such self-sustaining reactions, those that were best adapted to the environment (those parts of it they relied upon, e.g. available chemicals) would necessarily have left more "descendents" than others that were competing for the same raw ingredients (food supply). With these types of lipid membrance cell, new chemicals in the environemnt that were not part of the chain reactions occuring in the "population" would often have been introduced, and occasionally would have modified those reactions and their products. This source of variation would then have been fodder for natural selection (the winners swamping the losers out of the environment), and so it goes...
Very insightful (Score:1, Insightful)
Re:The paradox (Score:2, Insightful)
Sure. Like impoverished, backwards Rome attacking the advanced Gauls. Or the ignorant Persians versus their enlightened neighbors. Or the weak, agrarian English building the British Empire from the corpses of more industrially developed...everyone else they could find.
See the history of Earth nations to find that some cultures are scrapping for a fight.
One Thing I'm Sure You Guys Forgot (Score:2, Insightful)
The real problem is that people here, and within the field of astrophysics, would generally prefer to not consider something like that. There is a general aversion to thinking that we might have made mistakes in our own mathematical modeling of the universe -- so much so that we would prefer to postulate invisible matters and forces are causing the things we see with our telescopes.
Furthermore, pseudoskepticism is taking an increasingly prominent role in science these days. It's becoming instrumental in deflecting attention away from anomalous data. The existence of a possible answer that conforms to mainstream views is now sufficient to ignore the fact that many of these anomalies in fact formulate a cohesive story. If you dismiss each of the individual anomalies on a case-by-case basis, then you can easily miss any fabric that might connect them together. Pseudoskeptics have taken over wikipedia and have long ruled this forum here. Finding a place where evidence that clearly contradicts mainstream beliefs can actually be discussed in a rational manner is becoming increasingly difficult. Evidence and prediction are losing value relative to consensus. If we allow this transition to continue on its current course, we will convince ourselves that we've figured everything out before we actually have a theory of everything. We can quite easily cause ourselves to ask the wrong questions under these circumstances, and a theory of everything -- as well as alien communications -- will seem forever elusive. Make no doubt about it: our own perception of our own accomplishments plays a very prominent role in our ability to solve these sorts of problems.
Re:We're right here (Score:3, Insightful)
Just because we can't do D+D fusion doesn't mean an advanced civilization can't. Any civilization that expands into its Oort cloud is obviously more advanced than we are.
And since the density of the Oort cloud is roughly, let's say, zero, it should be incredibly energy inefficient to collect the deuterium.
The Oort cloud consists of trillions of comets, which are basically balls of dirty water ice. The average density of the cloud is basically zero, but I can assure you that a comet's density is far greater than zero. And these comets should be easy enough to find, since water reflects radar extremely well. The net energy gain from harvesting deuterium -- when you remember the almost complete lack of gravity out there -- will be huge.
Re:...or the opposite (Score:4, Insightful)
And how can you make sweeping statements about as of yet imagined beings and their society, and be condescending to everyone who isn't partaking of the same fiction?
Re:Have some patience, we'll run across them... ev (Score:4, Insightful)
Provided that one model of the inevitable course which all civilizations must absolutely follow is true.
You made one crucial mistake in the above... it doesn't take "all" civilizations, it takes only one. Only one civilization has to either want to expand throughout the galaxy, or wants to create self-replicating probes to explore the entire galaxy. Assuming intelligent life is relatively common, do you think it's reasonable that not one over the last few billion years would do it?
Re:We're right here (Score:3, Insightful)
I was using them as an example of a civilization of people whose basic needs were all met, and yet were still extremely violent to combat the parent's claim that the only possible reason for violence was to obtain resources.
Re:The paradox (Score:4, Insightful)
Even more irksome is when people make sweeping statements about things supposedly missing from science fiction that has in fact been extremelyv thoroughly explored over the decades.
(And trying to be slippery by qualifying with "run-of-the-mill" doesn't help, since that amounts to a circular reference -- if a story does address non-radio-signal communication, then it doesn't count???)
Even in the earliest "space opera" stories (e.g. E. E. "Doc" Smith and his cohorts) in the 1930's outright assumed that advanced civilizations would use telepathy, tachyonic communication, etc., and it was not rare even then to suggest that they had more or less forgotten about ordinary radio waves as hopelessly antiquated.
Decades ago there was one particularly amusing story (author and title forgotten, alas) with a series of vignettes, each suggesting a different and clever explanation for the Fermi Paradox e.g. one civilization was trying hard to communicate with Earth in particular, but they kept assuming that their data rate of e.g. one bit per year was too fast, so they kept slowing the rate down.
A very funny story (which I think is actually available online, these days) talks about the incomprehensibility, to members of a far-flung multi-species galactic civilization, of Earth having beings that "thought with meat", as opposed to every other galactically-known species that had brains of plasma or electronic etc. nature than were otherwise known. (This was not directly about SETI issues, but such are strongly implied.)
The ultimate problem is not a lack of imagination -- many, many exotic notions of ET communication have been considered -- but rather that the exotic modes are not pragmatic. If ET's communicate with tachyons, well, alas, we don't even know for sure whether tachyons exist or not, let alone how to try to receive them from ET's.
Interesting recent example: in quite recent years, it turns out that there is a previously-unnoticed theoretical prediction from quite orthodox physics, that photons can carry, not just their intrinsic spin of 1, but also an arbitrary number of additional units of angular momentum. This seems to be little-known, so far, and no one knows how to either produce or to detect that additional angular momentum in photons.
Nonetheless, many people immediately speculated about 2 things: whether cosmological events may produce such photons, and whether ET's might produce such photons.
Failure of imagination is not the problem. The problem is the pragmatics of turning imagination into a realizable experiment.
You complain about the failure of the imagination of SF writers, futurists, etc, but what that says to me is that you are unaware of the rich imagination long ago represented by such people.
Perhaps the problem is merely that you read only "run of the mill" or mediocre fiction and futurism, hmm?
We are indeed right here. (Score:2, Insightful)
All very ironic, especially when the answer to both questions is basically that we can't see the forest for the trees.
joudanzuki
Re:So, where is everyone? (Score:2, Insightful)
I think our galaxy is not conductive to travel or communication. Everybody knows planets with life are probably at least 100 years apart by any conceivable technology, but few actually come to think about our radio communication. Sure, our TV broadcasts have traveled in space for many many lightyears, but they've become incredibly feeble doing so. That, and they're mingled with all the radiation from our sun. The humankind isn't even coming close to using the kinds of energies that are constantly reflected from Earth's surface.
I did some calculations earlier and I'm sorry to say I've misplaced them, but it is my understanding that no signal mankind has ever sent could be picked up with the largest of our telescopes, from a few lightyears' distance. Another humanity could be in this very neighborhood and we couldn't know.
This is my favorite answer to the Fermi paradox. Travel over thousands of lightyears is obviously difficult and even if a race would do that, they wouldn't visit a star very often (it depends on if replicating probes are viable, though). Communication on the other hand would either require modulating your home star's radiation output or switching to a whole other unknown method.. And communication would be aimed, not omnidirectional..
Re:So, where is everyone? (Score:4, Insightful)
The reason the Fermi Paradox is interesting is that "recent" in astronomical terms is a long, long time in even geological terms. Even if what you say were true, there would have been many times the incubation period for intelligent life to develop between then and now, and we still should have seen something by now.
Maybe it's because God made us (Score:3, Insightful)