The Fermi Paradox The Fermi paradox (named Nobel Prize winning Physicist Enrico Fermi, instrumental in the development of the first nuclear reactor) postulated among a circle of like minded and intellectual friends when discussing the possibility of aliens versus there not being visible. I believe (although the tale is more than likely somewhat embellished and apocryphal) that he might have been playing devil's advocate and posed the conundrum as something like "if there are aliens...then where are they?" The paradox lies in the very high mathematical likelihood or probability of the existence of alien civilizations and yet the lack of any evidence of them (including, but not limited to direct contact) In our remarkable galaxy of over two hundred billion stars there is an extremely high mathematical probability of there being a good number of other stars in this Milky way with inhabited worlds. We can already detect hundreds of extrasolar worlds and its only a matter of time before earthlike and terrestrial planets will be found and catalogued. Our star is actually a rather young star, in a galaxy of stars millions of years older than ours, there is potential for some very old and sophisticated aliens. And if evolution works on their planets like ours, which it most likely would, as their technology increases their energy production would as well, regardless of how they communicate any civilization of regard would have discovered radio waves, because its part of the electromagnetic spectrum, which is universal, and they would have recognized how efficient it is at long range communication. But even if they used some other spectrum of radiation, the problem remains the same. This inability to detect any kind of signs of alien civilizations, and particulalry any kind of alien communication, has been deemed "the great silence". If there was say a Type I civilization capable of utilizing ten to the power of 16 watts for communication purposes, ten quadrillion watts (by definition humanity is not yet a Type I civilization) even a brief signal of theirs could be noticed over very sizable distances. A Type II civilization with ten to the power of 26 watts can harness the power of a typical sun and be detected over intergalactic distances. A Type III civilization can harness ten to the power of 36 watts, the typical power output of a galaxy. Such a civilization can be seen just about anywhere in the universe, even a fart from one of those aliens would set off all kinds of bells and whistles here on Earth. Arguments against the paradox, or possible explanations/complications: 1)Intelligent aliens are much too rare in the universe. It took about 3.5 billion years for the first multicultural life to appear on Earth. Life may be very common in the galaxy, but not intelligent life. It takes much too long for evolution to happen, and evolution can't happen too quickly, it can kill an organism to mutate too rapidly because natural selection cannot possibly plan on what mutations will be beneficial or not. Environment factors in too, and environments change. The evolution of just one intelligent species (humanity) on one planet is poorly understood, attempting to extrapolate for alien scenarios borders on our ignorance. 2)There are a given number of intelligent species at any given time, but separated by distances (or times) too great Even if humanity survives as an intelligent race for a million years, a million is less than one tenth or one percent the age of the galaxy (13.5 billion years). The universe is at least several eons older. It could be that a good number of intelligent races have visited our Earth in the remote past when the surface was still molten and incapable of supporting any life, let alone intelligent. It could be that such aliens went extinct eons ago, or that in many ages hence, we shall be the dominant and only aliens existent. 3)We are too technologically backwards Champions of this line of reasoning may suggest that humanity propagating alien data through radio is like an ant beating out Morse code on the sand off a busy road intersection. It could be that aliens no longer use radio to communicate, if ever, and are using some exotic yet-to-be-discovered particle that we have no way of detecting. They may encrypt their broadcasts, or it may occur in nanoseconds, making all of our attempts to listen in on their conversations meaningless. If there are aliens somewhere, intelligent aliens no less, would we not have heard from them by now or seen evidence of their existence? Considering that intelligent aliens would naturally develop into very advanced civilizations, (unless going extinct) with technology such as radio telescopes, and radio waves of significant strength propagating through the galaxy that could be detected by even primitive ham radios. Its an intellectual mind game, intellectual masturbation, but a useless tool for reasoning out this persistent question of humanity's. I am eager to hear your thoughts on the subject. "There are two possibilities, either humans are alone in the universe, or they are not, either possibility is equally frightening..." Arthur C. Clarke
I'm sort of a champion of UFO lore. I'm not going to wax intellectual on this subject. Instead, I'm going to tell you some very interesting stories that happen right in front of us. For example, friends of Bob Lazar reported that aliens did visit earth, and were even working with the United States government, which is also why the soviets ordered all UFOs to be shot down, while in other airspace they were just observed. Long conspiracy short. The aliens decided not to work with us. Reason? Two Army M.P.s entered a room where the Grays were without removing their pistols. The Grays asked them to remove their sidearms because the bullets inside their guns would explode if they came near their technology. Reasonably the M.P.s kept their pistols, and were subsequently killed along with one of the Grays. Bob Lazar himself was an interesting individual. A former employee of Area 51. He drew schematics of Alien craft and described them in detail. Now I like stories like that, because they show imagination, but there are much better ones that have less imagination but have real witnesses. Shag Harbor was something like that. First, we have dozens of fishermen reporting a bright crashing object. Then, as they surround the object, it glows underwater. Police boats confirm this along with a thick yellow foam that seems to be spilling out. The Navy is called, they send divers down and report a metallic disk shaped craft that appears to be glowing. Several days later, the entire town watches it speed away from the water and take off into the air. This is a confirmed report from first responder witnesses, police and military officials. Along with that, there are hundreds of pilots that can say they've seen some strange ****. I live near Edwards AFB which is where the shuttle lands on bad days. For awhile, every Thursday at 7:30 a plane would create a huge sonic bomb over our house, sometimes flying so low we could even hear the unmistakable sound of a SCRAM Jet. Which sounds something similar to a slow air pump from hell. But beyond that. Are we alone? Gee that's a big question, but tell you what, it doesn't matter. Humans are probably 100 years away from having some pretty significant computer technology, only 20 years away from photo realistic graphics processing. Projects that are working to map the human brain to a computerized interface are very exciting, since if this computer program, replicating a human brain, was to be run like a client server process, the speed of thought could be altered such that entire eons take seconds. If we build it they will come? Maybe. The end of suffering for a race and infinite heaven for what is no longer medically considered our mortal soul. Forget warp drives. Lets work inward. I'm sure any other intelligent species that is beyond us and can manipulate time has found far better things to do with time then look at stumbling monkeys.
Depressingly, we may just be alone. When you look at all the factors that are considered a pre-requisite for life, then you begin to appreciate just how incredibly difficult it is for life to grab a foothold. First of all, you require a star at the right stage of its life, not at the beginning nor in its death throes. You need that star to be of the right classification in terms of the heat that it gives off (basically a "G" type star), and you also need that star to be a "solo" star rather than one that is part of a binary system, in order to create the gravitational conditions that would allow planets to form. Those three factors alone would eliminate possibly 99% of all stars in our galaxy. Then you need that star to actually have planetary formation around it, and for a planet to actually exist at the right distance from the star in order to have a chance of creating the conditions that could support life. That maybe reduces us to 1 star in 10,000 that meets these requirements and actually has a suitable planet. But even then we are told that the first life on our planet formed in rock pools caused by tides, which in turn were caused by the gravitational pull of our moon. So, without the moon, there would quite possibly be no life. And there are many more factors that could and should be taken into account. Sure, the sheer mathematics of numbers with regard to stars in our galaxy would still create thousands of genuine contenders for life, but the chances are that it is extremely rare, and perhaps even unique.
Thanks for responding guys! Nobeler: I have to admit, I am actually a bit of a UFO skeptic, I'm actually a big skeptic about most things, especially UFOs:redface:. I have my reasons but won't get into them here and now, if you want I would love to talk it over with you though. As you said, I think we may be too dumb to figure out alot of things, but I think that we're at least smart enough to observe the universe in a multitude of spectrums and deduce intelligence. For example, extraterrestrials may have stellar engineering feats under their belts, such as building Dyson's Spheres and Ringworlds. Even though they may be very far away, and too far away to visit in centuries or tens of centuries, we are beginning to see things once only hypothesized, like extrasolar planets. It used to be that the only planets we found were brown dwarves, giant Jupiters, but now we are beginning to "see" super earths. It is only a matter of time before we find the first of many possible alien earths. Halcyon: good points, but I have an issue with the "Goldilock zone" conceit that a star's heat and distance have to be "just right" for life. It presupposes that life requires a specific heat, when in reality, like the extremophile lifeforms of Earth, extrasolarlife might be very resilient and adaptable. Europa is the perfect example of a body that should be bone dry and cold as ice and yet has liquid water underneath the surface because of outside influences. The universe is more than likely full of interesting surprises like that.
My few cents worth I belive aliens without a doubt exist. as you said the numbers of stars in our universe is to great for there to be only one earth-like planet. I do not belive that aliens have come to visit us. If they have it would be hard for even the u.s goverment to cover up. I mean they cant even conceal their real intentions for wars ( which in most cases aren't what they tell the public ). how are they going to conceal something as earth shattering as the knowledge that we are not alone. Now lets say that some country has contact with aliens would it not make sense to scrap projects like the huge satalite dishes they are using to pick up ( at least hoping too ) alien communcations. now let's say we do pick up something. with the internet being responsible for every little piece of knowledge you could want being dilverted to you within in hours of it happening do you realy think anyone could conceal it. Also alot of the UFO sittings that people video tape of compeltly faked and are either staged or computer rendered. As I said before we cant be alone. But, What reason do aliens have for coming here ? what could we possible offer someone who cant travel through out of own solar system ?
Good point, but if I can counter with a cliche, though we may be as an insect to a very advanced race there are people who spend their entire lives capturing and studying "bugs". I'm thinking, (and hoping) that life and if not at least intelligent life may be at least a rare enough thing in the galaxy that it makes our potential visitors/listeners curious about us. While I don't think first contact is very likely anytime soon, I am a bit dismayed about the "great silence". The galaxy should really be flooded with chatter after a few eons.
The human mind has difficulty dealing with really huge nimbers. The vast number of stars in this galaxy alone makes the probability of other intelligent life extremely probable. There have been calculations, but as many of the numbers going into those equations are Wild-Ass Guesses (tm), it's hard to pin down the exact probability. Also, these equations are based on life based on a similar biochemistry to our own, so it doesn't consider biologies that could exist and develop intelligence under conditions completely hostile to our biology. But that being said, let's assume there are twenty thousand intelligent, spacefaring carbon-based, oxygen-breathing species in the Milky Way galaxy. The galaxy contains between two and four hundred billion stars, which means each species could explore about a million stars without encroaching on any other species' territory. That kind of odds makes it pretty unlikely that another species would happen to stumble across our rater ordinary solar system and take an interest in our planet Earth. The same argument can be extended across all the galaxies comrising the universe, but the overall percentages don't change. I personally believe life is more prevalent than that. From what we have seen, life is a highly opportunistic process. If there is a niche to receive it and sustain it, it will probably develop. So the number I chose, two hundred thousand species is probably conservative. But just as we might have difficulty recognizing life forms based on Helium II at cryogenic temperatures, other life forms may not easily recognise us as life forms, or to be worthy of extensive study. So yes, I believe there is intelligent life out there, a lot of it. But there is an awful lot of "out there" for them to explore.
I like to simplify problems like this. Go stand in a room wearing a blindfold holding a revolver with 300 chambers but only two bullets loaded non-sequentially and 298 blanks. You now have to fire the gun, spin around until you pass out and repeat until your ammo is spent. The odds of there being other aliens and us meeting them are much like the odds of you happening to fire your second bullet through the hole created by the first. Even with the guarantee of two bullets, the sheer possibility of physical locations makes the likelyhood of direct contact highly improbable. I personally do not disqualify the possibility of life on other planets, intelligent, developed or otherwise. But only in the same way that I don't disqualify the existence of unicorns: They may very well exist, but you're wasting your time looking for them.
The thing is, we don't KNOW what the probability is of finding intelligent life arising from a planet around a star. We are starting to get a handle on how likely it is to find planets around a given star, and it looks like planet formation is very probable. But we just don't have enough data to project the probability of life forming, or the likelihood of advanced civilization at a given time on a life-bearing planet. Back to the Wild-Ass Guesses (tm). Even if one in every thousand stars has given birth to intelligent life, currently active, that is still a lot of space for them to explore. We ourselves have only set foot on one ball of rock (the moon) outside our own world, and the difficulties of interstellar travel are still beyond our reach. Even if we do solve it, it may still be very difficult to explore to all the stars we are interested in. There could be many millions of civilizations out there. The few that may figure out how to explore on a galaxy-wide basis are still unlikely to stumble across us unless they have a way to narrow down the search, implying there is something interesting about us from their perspective. As I have already said, the numbers are not easy to grasp intuitively. It's the same kind of thinking that fool people into sinking substantial money into lottery tickets, considering them an investment.
if they don't I'd be curious to see how they define life I'm sure the classic 4 R's of life processes (Respirate, Respond, Reproduce, Regulate) are invalid on other worlds but a good place to start
Stephen Hawking made a great point about this. He essentially said that we nearly killed ourselves off on several occasions in the last 50 years. We can't even now keep ourselves from killing one another. We WANT to get ahold of a more technologically powerful race, and wave them down here on Earth? He suggests we just shut up and wait for us to get to Type I stage, otherwise we may see a Columbian style occurrence like when he visited America 320 years ago.
With all deference to the brilliant Dr. Hawking, I feel he is attibuting too much of human nature to unknown aliens. The risk exists. There is also the risk they will be aggressive and hostile in ways we cannot comprehend, or that they won't even consider us sentient, and either use us as food animals or exterminate us as pests in areas they choose to build bases. I think they are also likely to take little interest at all in us, or study us without interacting with us. Not because they would feel superior, but simply because we are so different. The universe has room for nearly infinite variety, amd I expect that to extend to life and intelligence as well. Most movie aliens are bipedal, laterally symmetrical creatures with a top-mounted brain case and sensory clustor, including stereoptic imaging, mostly because that makes for easier portrayal by human actors, and easier for human audiences to relate to. And all life on our planet derives from a common biochemistry, and an original structural template. All vertebrates show a similar skeletal structure, and a similar organ arrangement. Our appendix, for instance, is a degenerate second stomach that remains fully functrional in ruminants. There's nothing inherently superior about our structural design, and in fact any decent engineer can find serious flaws and shortcomings. Alien species can be expected to be VERY different. (Before someone brings up the religious argument that we are made in God's image, and therefore aliens would share the same shape, God's image may not be so literal as to mean physical shape. It may mean simply (e.g.) that we share the ability to reason, to classify behaviors as right or wrong, and to show compassion). My point in this ramble is that aliens will likely be very different from us in nearly every conceivable way, so we should be wary of anthropomorphizing them too much.
We dont know that either way. We dont have a standard yet that explains what or why will allow us to traverse space. For all we know, hind legged creatures fare better in space then four legged for some reason. Until we meet another interstellar race of intelligence, we just dont know. FYI, the OP mentioned it taking 3.5 billion years for life: This is not true. Theres a LARGE grey area where life began and when Earth became SUITABLE for life. There are theories that state how carbon based proteins that created life came from space, and not Earth itself for several reasons, and like planting a sapling, Earth was just the best choice and survived to evolve to this point.
Then again guys, in Slaughterhouse Five, the universe is destroyed by a Tralfamadorian test pilot whose craft we can only assume creates and destroys universes with ease. Also they live in the fourth dimension which is pretty wicked. You'd be phased out, like ghosts. Then you've got the story of the Mothman, and he's just a little bit more important than the Jersey Devil in terms of things because he had a movie. And I think now I realize I keep going back to folklore when I relate to this topic because I think things like Dyson Spheres and Ring Worlds might be absolutely loony. Sort of like Steampunk, or what, you know, people in the 1800s thought science fiction was like. Don't say remarkably true, not all dime store sci-fi authors were Jules Verne. I dig on what Cogito is saying here. It's likely things are very far away, and very different. Human's have a tendency to make their own destiny. I wish we would do that as far as creating paradise was concerned.
I think that the analogy Hawking prefers is the Conquistador/Native American scenario where the former was technologically superior. I think it's a slightly unfair although reasonable comparison. My problem is that the Spanish Colonialists where imperial in nature and not exactly predisposed to help anyone, they came to conquer, and did. The effect was also two-sided, while "Indians" died from muskets, Spaniards were dropping dead from Malaria; getting sick much like the Martians in "War of the Worlds". While it's unlikely for an alien lifeform to be vulnerable to Earth-evolved pathogens it's a good reminder that an alien planet may be very hostile to an...alien. When I was a boy I read alot of Clifford D. Simak, who did not write alien invasion fiction with the exception of one short story called "Skirmish". In the intro to same titled anthology he explained why alien invasions are unlikely, and seem silly. Essentially, if we look for the reasons why they may wish to invade, what are they? 1)Resources? Any alien that can bridge the stars is no longer dependent on planetary resources, not only that, if they have the freedom to other planets they might decide to land on uncontested worlds instead. Water is insanely easy to find and make, Hydrogen, the fuel of stars, is the most abundant and simplest element in the universe. 2)Slave labor? They would have complex machines and wouldn't need slaves. 3)Breeding stock? They may not be genetically compatible, and it's absurdly unlikely, despite some of the more campy and sexually suggestive pulp fiction covers. 4)Land? Again, I find it unlikely that the galaxy can't harbor a planet someplace suitable for them. And if they can't... 5)Colonization? They may be able to terraform uninhabited worlds, but unless their race has a relatively small population (a mother ship of a million people maybe, like the aliens in Independence Day) the logistics and economics of massive colony ships is one thing, on top of that the aliens would need an invasion force capable of wiping us out...which actually might not be that hard for them 6)By the point an alien race has reached the stars they might have reached a level of civilization and sophistication that makes them ethically opposed to the idea of enslaving or conquering other sentient beings. Don't laugh, once upon a time there were no rights for animals. Now at least our favorite critters get protected by laws. People are even beginning to empathize with the planet. If we can sympathize with a giant rock, we are on the right track. Eventually I think our species can reach the ethical high ground of Starfleet in Star Trek or the Nox in Stargate: SG1. Starfleet had laws like the Prime Directive in place to protect aliens, and with great power comes great responsiblity. Not that laws can't be broken, but it should at least be a rare event in such a big galaxy. You need to read the OP again, I didn't say that life took 3.5 billion years, multi-cellular life did.
once again we assume it did merely because we are the sole example. For all we know, multicellular life came to Earth and proliferated. We werent there, or have witnessed it, so its up in the air.
We don't assume anything actually, all the evidence points to that. The fossil record doesn't lie. Whether or not life arrived here from space is academic, whether or not it evolved here is much harder to dispute. did life get transported here? did it? can you proove it? can you verify it? can it be demonstrated? For all we know the intergalactic lord Xenu, in all his magnificence, transported us all here millions of years ago in starships that looked like DC-10's. Unless you evidence for claims, I don't take it very seriously. Yes, I know that comets have been found to have organic molecules. Yes, they have hit us before. Yes, such a body could have seeded our planet with proto-life. Yes I have heard of panspermia. Yes, have heard of directed panspermia. Until I see some better evidence, there's no need to start re-writing the textbooks. QED. oh, and BTY, FYI, at the risk of sounding like a pompous ass, I think you owe me an apology because you accused me of saying something that I didn't actually say and then corrected me on it
you want an apology for a comment on the internet? Okay, i'm sorry. FYI, the fossil record is only 600 mil. years old. So accounting for 2.8 billion years in your gap doesnt make sense. We dont have any proof beyond the hard shells of 600 mil. years to explain how multicellular life got started here.
the oldest fossils are stromatolites and they're billions of years old, what scientific texts have you been reading?
