Kurzgesagt - Why Alien Life Would be our Doom - The Great Filter - General

I interpreted "the barrier" as a barrier, not so much a humanity annihilation protocol or inevitable death countdown, but a limitation of how far the tech is able to advance. The species that die out were just stuck at the barrier, surviving for a long time before dying, but that long time is kind of insignificant compared to the time we've been around and they haven't put any indication out there because they can't, since they're stuck at the barrier.

[QUOTE=download;53099753]Not sure I agree with their argument. They basically stated that that the existence of large amounts of intelligent [I]interstellar space-faring[/I] life would be terrifying because it indicates the filter is in front of us. But it could also mean the filter is not as great as we thought, or that there are multiple less-great filters instead of one. Even if the filter is a great filter, the existence of lots of space faring races might still not mean it's in front of us. The galaxy is huge, and having one-hundred space-faring civilisations in it still means only one in a million potentially life-bearing planets actually made it.[/QUOTE] I think you slightly misunderstood the point here. They specifically didn't mention (active) interstellar civilizations, because you're right that really wouldn't imply much about the filter. The further back in the evolutionary chain any alien life we find is, the less it implies that any potential "great filter" is still in front of us.

I think some of the people in here aren't understanding some basic things. Let's assume the development of life, to the point of current human civilization, is common. Why is that bad? Well, there are earthlike planets out there that've potentially had billion year head starts on us. Wouldn't multiple billion year old alien civilizations leave behind some sort of trace? After billions of years, how much of the galaxy would you expect to be colonized? Life grows and spreads exponentially. Let's say that it takes a thousand years for a new alien colony to send out two colony expeditions. It would still only take 35,000~ years to colonize 10 billion worlds. If interstellar travel is possible, and intelligent life is common, then the galaxy should be teeming with life. But it doesn't seem to be. Which means we'd probably be fucked.

[QUOTE=Mr. Scorpio;53100693]I think some of the people in here aren't understanding some basic things. Let's assume the development of life, to the point of current human civilization, is common. Why is that bad? Well, there are earthlike planets out there that've potentially had billion year head starts on us. Wouldn't multiple billion year old alien civilizations leave behind some sort of trace? After billions of years, how much of the galaxy would you expect to be colonized? Life grows and spreads exponentially. Let's say that it takes a thousand years for a new alien colony to send out two colony expeditions. It would still only take 35,000~ years to colonize 10 billion worlds. If interstellar travel is possible, and intelligent life is common, then the galaxy should be teeming with life. But it doesn't seem to be. Which means we'd probably be fucked.[/QUOTE] Firstly, life as advanced as Humans means nothing. We can't get off our own rock, so they couldn't either. Seeing as we have a hard time sending signals out of our solar system, and no reason to do so, there's no point in assuming they would either. It's the blind searching for the blind with their mouths gagged and they're all in different countries. Secondly, the timescale of 1 billion years is so meaningless I can't believe people bring it up. Humans have been around for only a few hundred thousand years, surely the billions of years of NOT developing even basic tools would be the norm. Assuming more time = more likely to develop interplanetary technology is baseless. Look at sharks, they're apex predators who have remained virtually unchanged since the time of the dinosaurs. There's nothing to suggest that intelligence is a desirable or inevitable trait in evolution. Even if there were billion year old civilisations and they did have the technology to colonise other worlds that doesn't me [i]we[/i] have the technology to detect them. Thirdly, life does not grow and spread exponentially. Life grows at varying rates depending on its environment, life also grows over other life. It's not a tower that gets taller with every new living creature added to it. The assumption that the creation of one planetary colony means the possibility of another is an enormous leap. First off you have to consider that the technology to colonise one planet does not translate into the technology to colonise all planets, second you have to understand that colonisation happens due to a need for space or resources, it's not something which happens for no reason, and thirdly it assumes that there are no societal collapses in the span of 10,000 years. Which is great, tell me when it actually happens. As for the whole colonising 10 billion worlds thing that assumes the need, desire, and ability to continue colonising. Also ignoring political strife. Interstellar travel which allows for rapid expansion also allows rapid trade and conflict to follow. People understand these things, don't belittle them. It's just that I don't think you appreciate just how fucked huge space is. Just our galaxy alone is so huge it would take hundreds of thousands of years to reach the nearest star, an immediate roadblock to your 2 colonies every 10,000 years idea. Faster than light travel is not, and will never be, a thing.

[QUOTE=Zillamaster55;53100315]The Great Filter and Fermi Paradox feel like great excuses to stop exploring space and completely shuttering evolutionary studies, tbh. “We’re the only ones that exist, we’re the only ones that matter, nobody else is there and there’s no point in looking because we’re special” sounds pretty bible thumpy to me[/QUOTE] No. That is not the point of the Fermi paradox.

the real great filter is the blockade put around our solar system by the greys when they purchased harvesting rights to keep other species from poaching us

[QUOTE=download;53099753]Not sure I agree with their argument. They basically stated that that the existence of large amounts of intelligent [I]interstellar space-faring[/I] life would be terrifying because it indicates the filter is in front of us. But it could also mean the filter is not as great as we thought, or that there are multiple less-great filters instead of one. Even if the filter is a great filter, the existence of lots of space faring races might still not mean it's in front of us. The galaxy is huge, and having one-hundred space-faring civilisations in it still means only one in a million potentially life-bearing planets actually made it.[/QUOTE] No, the point is that there have been planets in Goldilocks zones for billions of years in our galaxy before ours, so if life truly is common and intelligent life naturally develops from there, there [i]should[/i] be one gigantic galaxy-wide civilization by now. But there's no evidence of that. This means that either our understanding of life is wrong OR (what is proposed in the video) that there is something that all intelligent life inevitably leads to and wipes it out. [editline]1[/editline] [QUOTE=_Maverick_;53099768]Is it not also possible that there is NO great filter?[/QUOTE] Unlikely given that we don't see any alien civilizations anywhere in our galaxy. If our understanding of life is correct, then we should see something if there isn't one. Of course we could just be extremely unlucky with where we look in the galaxy for life, there is still most of it we haven't really looked at yet.

I just straight up don't understand why other life existing proves the great filter exists. Like he explains the great filter and then says that's why life existing before or after us on the evolutionary level would be a bad thing, and it seems like quite the leap. How does life existing at any point prove that there are filters that prevent life from existing beyond a certain point?

[QUOTE=Rufia;53099810]Seems somewhat of a sensationalist conclusion to draw from very little information.[/QUOTE] Statistics is a science, and one that has proved its accuracy for a century now. Scientists have taken a sample of the sky, much like they have taken a sample of a human population or a gene pool or anything else, and made an observation and deduction using it. [editline]1st February 2018[/editline] [QUOTE=Rossy167;53100952]I just straight up don't understand why other life existing proves the great filter exists. Like he explains the great filter and then says that's why life existing before or after us on the evolutionary level would be a bad thing, and it seems like quite the leap. How does life existing at any point prove that there are filters that prevent life from existing beyond a certain point?[/QUOTE] Finding other life indicates that life IS common which then increases the probability of a galaxy-wide civilization by a significant degree - but we still haven't seen one. Finding more life makes the probability of a "great filter" incredibly more likely.

stolen from reddit [QUOTE]I think a lot of people are misunderstanding the Fermi Paradox. Not hearing radio signals is just one part of it. The Fermi Paradox is based on the calculation that, even with modern day sublight technology, it would only take a few million years for a civilization to colonize/send probes to the entire galaxy; including our solar system and nearby stars. On top of that, a civilization advanced enough to do that would potentially be able to build dyson swarms (or similar superstructures designed to maximize a home stars power output), which might only take a few thousand years to construct (a blip in cosmic time), and likely around more than one star. Such a “structure” would be easily detectable with current astronomical tools due to unnaturally inconsistent wave form fluctuations. But it’s been billions of years since the birth of our galaxy, and none of that appears to be the case. We see nothing, anywhere, to indicate any presence of star-utilizing civilizations; something our own is nearly capable of doing only a couple centuries after industrialization, and less than a million years since evolving into Homo sapiens. Statistically speaking, there *should* be at least several thousand intelligent species somewhere in our galaxy alone, and at least one *should* have figured out how to break out of its home system. But, as far as we know, none have. Not detecting radio signals is one part of it, but the Fermi Paradox is really more about trying to explain why the entire galaxy isn’t already teeming with advanced life when, according to even conservative probability calculations, it absolutely should be. Hence the “solutions” proposed to the FP, like The Great Filter. It’s just a theory, one of many competing theories, to explain. Others propose that humanity might be among the first, or that life is just way rarer than we thought. Some get really crazy, like we’re just living in a Matrix-like simulation, or that we are already surrounded by advanced civilizations and are just under observation (The “Zoo” hypothesis). Sorry for the long post I just love this sort of thing![/QUOTE]

Or literally the simplest explanation that also fits in with reality and physics: We literally can't observe them because of the massive distances and times and inaccuracy in equipment and basically an endless list of problems that say, "You won't see shit." And further that any civilization can and will simply expand infinitely in all directions to fill all potential space is an entirely absurd and baseless notion. Look at what we do already: Build up, not out. We prefer to take the space we are currently in and cram as much as we can and bleed out at the edges than simply expand to fill every single space available evenly.

Also a dead universe is the "best" possible solution because even us utilizing modern or technology that's very close off it's possible that whoever gets to space first would destory everything: [quote]Nuclear Pulse Propulsion can get us to the stars at a maximum velocity of 0.1C assuming that you have to decelerate again, if not you can reach 0.15C which will be important for latter. Also we will assume that there is no faster than light travel. Because that would open up another can of beans since humanity could convert an amount of mass equal to the observable universe into human flesh in 6,000 years if the 1994 population growth rate could be maintained. And it could be maintained if the superluminal travel would allow humans to access new resources fast enough. So assuming that you could send out self replicating probes that would travel at an average velocity of 0.1C and that it would take each probe 100 years to make a 100 copies of itself each time that they entered a new stellar system, you could still visit every stellar in the Milky Way in under 1 million years. If theses probes carried humans or mechanized human descendants then our civilization could also spread as quickly. If you programmed these probes to seek out life bearing exoplanets and crash into them an top speed, which for nuclear pulse propulsion is .15C if you burn all the fuel and don't plan on decelerating, you could purge all the life bearing planets in the galaxy and keep yourself safe from aliens forever. And if you programmed those same probes to accelerate toward any repeating, terminating radio signal and crash into the source body you could all target intelligent species. For that matter you could have them detonate there bomb stockpile before impact to scatter relativistic shrapnel cones at space habitats. And that doesn't even account for the danger of other species colonizing everything and taking all your resources. Basically your only real option to keep yourself safe is to attack with berserker probes first and hope that you can get everybody before they launch their own. So you need at least a million year lead on your galactic war to ensure your own survival. In a universe were superluminal travel cannot exist, any species that creates even the most primitive form of relativistic vehicle and self replicating machinery is an immediate and lethal threat to all other forms of life. Because of the rate at which intelligent life can spread, you pretty much have to attack all alien intelligences without provocation and with even knowing if there is anyone to attack. As previously stated probes with a maximum practical travel velocity of .1 C could visit every stellar system in the galaxy in as little as 250,000-1,000,000 years. Now with speculative but still possible technology it could be done even faster. Even if we discount confined fusion as an energy medium for a reaction engine, hydrogen/antihydrogen reactions could still be used and we know they would work if there was enough antihydrogen. The solution to that being solar powered particle accelerators orbiting in the inner solar system. They would take in hydrogen from the solar wind and produce antihydrogen using abundant energy. A laser assisted launch could also increase the acceleration of outgoing ships of any type if a large solar powered array of lasers with an output greater than a terawatt was used. All this culminates in the ultimate plan for species survival, to completely disassemble the all the rocky planets of every stellar system we can get access to and use that mass to build Dyson Swarms of space habitats around the local stars. That way we can continue to survive around those stars until they burn out, which in the case of the lowest mass red dwarfs would be about 120 trillion years. The largest lofstrom loops possible with current engineering can lift 500 million tons a year and since you could only fit about 1000 on earth it would take nearly 10 million years to disassemble the planet. But it can be done only with proven technology, no super materials or new energy sources needed. You could power them using huge convection towers that contain liquid halite, which would be heated by the hot lithosphere you are uncovering. And of course the job would only get easier as the planet is taken apart: less gravity, more heat being radiated, more materials for building and maintaining the loops. That said you still have to use nuclear pulse propulsion to move the material for the first loop into orbit, about 2 million tons of it. But with nuclear pulse propulsion that is doable. We can conquer the cosmos with only what we know today, no soft scifi stuff needed. It will just take a very, very long time. Now of course you can't disassemble stars, or for that matter high mass objects like gas giants. But the earth sized planets or at least large portions of their lithospheres can be consumed. Sauce: The actual Project Orion documents about nuclear pulse propulsion if anybody wants them. [url]http://web.archive.org/web/20071022133749rn_1/www.mfbb.net/nuclearrockets/nuclearrockets-about12.html[/url] The Launch Loop - A low cost earth-to-high-orbit launch system LOFSTROM, K H AIAA, SAE, ASME, and ASEE, Joint Propulsion Conference, 21st, Monterey, CA; United States; 8-10 July 1985. 1985[/quote] tl;dr Unstoppable self replicating near relativistic velocity suicide drones would not only be possible, but very probable and the only safe bet because if your civilization hasn't someone else has first and you won't know until it's millions of years too late.

What if we are the aliens?

[QUOTE=richard9311;53101032]Also a dead universe is the "best" possible solution because even us utilizing modern or technology that's very close off it's possible that whoever gets to space first would destory everything: tl;dr Unstoppable self replicating near relativistic velocity suicide drones would not only be possible, but very probable and the only safe bet because if your civilization hasn't someone else has first and you won't know until it's millions of years too late.[/QUOTE] a million years sounds like a lot of time to come up with a countermeasure, even if you're not sure they're coming [i]while you were sending suicide drones to destroy life across the galaxy[/i] [b]I studied the blade[/b]

[QUOTE=Drury;53101116]a million years sounds like a lot of time to come up with a countermeasure, even if you're not sure they're coming [i]while you were sending suicide drones to destroy life across the galaxy[/i] [b]I studied the blade[/b][/QUOTE] *teleports behind you* I mean, if you had some sort of system that could not not only send out signals faster than the things going .15c, but then receive them, and feed that to something that could calculate shifting trajectories and send something to intercept an object that fast.

[QUOTE=richard9311;53101191]I mean, if you had some sort of system that could not not only send out and receive signals faster than things going .15c, but then receive them, and feed that I to something that could calculate shifting trajectories and send something to intercept an object that fast.[/QUOTE] well shit that sounds like a problem hold on, give me a million years on the toilet and I'll come up with something

[QUOTE=Drury;53101210]well shit that sounds like a problem hold on, give me a million years on the toilet and I'll come up with something[/QUOTE] Or a nice, long shower. Best ideas in there, I tell you.

[QUOTE=richard9311;53101032]tl;dr Unstoppable self replicating near relativistic velocity suicide drones would not only be possible, but very probable and the only safe bet because if your civilization hasn't someone else has first and you won't know until it's millions of years too late.[/QUOTE] if there's science I trust most it's cold war era theories boiling down to "someone, somewhere, is probably an asshole like our own paranoid tribal low tech war-mongering asses so they will, and thus we should, probably try to kill literally everyone else first. Just in case"

[QUOTE=Karmah;53100204]I too think their theory is a bit rubbish, even though I love this channel and their content. Also, early phagocytosis leading to complex life happened at least [B]twice[/B], did it not? We see mitochondria, but the photosystems of plant life also resembles that of algae. I'm pretty sure I learned that in one of my genetics courses at least.[/QUOTE] Did a little reading into it and ye, theory of Symbiogenesis likens the chloroplast quite heavily to cyanobacteria. You've also a symbiotic relation between a bacterium and protozoan (Angomonas deanei) with a very similar strong bond, with the bacterium unable to reproduce by itself.

At this point anybody in this thread who still claims something along the lines of 'we haven't seen multiple solar system spanning civilization yet thus there is something that destroys them before they reach that point' isn't reading the fucking thread. 1) We don't have the means to see jack shit outside of our own solar system, whether it's simple life on exoplanets, or interstellar civilizations. We just can't do that. We're blind. Any argument that deduces 'no advanced civilization exist' from the fact we can't see them is automatically bullshit. 2) Even if we could see everything and we couldn't find any multi-star spanning civilization, it wouldn't mean that something ends up destroying those civilizations before they reach the 'space' age. The simplest explanation is that colonizing planets outside of your own solar system is extremely hard to pull off. The assumption, again, is that technology grows exponentially while completely ignoring hard physical limitations, which is not realistic in the slightest. Interstellar colonization may very well be impossible, and there isn't that much of an incentive to do so in the first place anyway. [QUOTE=Firetornado;53100995]stolen from reddit[/QUOTE] Occam's razor -> So-called 'dyson swarms' are either impossible to construct, impractical, or extremely hard to pull off. End of the 'argument'. No 'Great filter' necessary. [QUOTE]something our own is nearly capable of doing only a couple centuries after industrialization[/QUOTE] LMAO. Not even close. Another 'technology grows exponentially guys' bullshit wankfest. [QUOTE] and at least one *should* have figured out how to break out of its home system[/quote] [Citation needed], can anyone here prove that interstellar colonization is indeed possible at all? [QUOTE=ForgottenKane;53100947]No, the point is that there have been planets in Goldilocks zones for billions of years in our galaxy before ours, so if life truly is common and intelligent life naturally develops from there, there [i]should[/i] be one gigantic galaxy-wide civilization by now. But there's no evidence of that. This means that either our understanding of life is wrong OR (what is proposed in the video) that there is something that all intelligent life inevitably leads to and wipes it out.[/QUOTE] The 'Goldilocks zone' doesn't guarantee the development of life at all, let alone advanced civilizations. It's just [I]minimum requirements.[/I] It's your understanding of life that's wrong. [I]Yet another[/I] baseless assumption. [QUOTE]Unlikely given that we don't see any alien civilizations anywhere in our galaxy. If our understanding of life is correct, then we should see something if there isn't one.[/QUOTE] Or we don't see shit because we don't have the means of seeing shit. We can only see if there's a massive object in a nearby system [I]if we're lucky.[/I] That says nothing of life or civilization. EM waves with a comparable power to ours are undetectable outside of their own solar system. We just can't see shit. [QUOTE]Of course we could just be extremely unlucky with where we look in the galaxy for life, there is still most of it we haven't really looked at yet.[/QUOTE] Or we just can't see anything at all given our current technology. [I]Again,[/I] the only thing we can measure right now is whether a [I]massive[/I] object goes in front of a star at some point. Not really something that gives us the exhaustive characteristics of the entire star system. [QUOTE=ForgottenKane;53100960]Statistics is a science, and one that has proved its accuracy for a century now. Scientists have taken a sample of the sky, much like they have taken a sample of a human population or a gene pool or anything else, and made an observation and deduction using it.[/QUOTE] But statistics don't tell us whether there's life or a civilization in the goddamn [I]shadow[/I] we study. We don't have the tools to tell whether those planets are populated. Quit making baseless assumptions. [QUOTE]Finding other life indicates that life IS common which then increases the probability of a galaxy-wide civilization by a significant degree[/QUOTE] 10^6 time 10^-15 isn't very much. The point being, we don't know how probable it is for basic life to transition into advanced civilizations. You mention statistics, yet the only data we have is our own civilization, which isn't representative of the entire universe [I]in the slightest.[/I] Every single value in the Fermi Paradox is made up. [QUOTE]- but we still haven't seen one. Finding more life makes the probability of a "great filter" incredibly more likely.[/QUOTE] Nope. The so-called 'Fermi paradox' is just a concept aimed at sci-fi nerds which is built out of ludicrous assumptions that are based on basically nothing. It's even more hilarious that people bring up 'statistics' when every. Single. Probability in the equation is basically made up.

The Fermi Paradox wasn't even designed to be used outside of a thought experiment. Its people down the line who are abusing the Fermi Paradox, just like edgy teenagers abuse nihilism.

The fermi paradix DOESNT state we're alone. It's a question/thoughtful position about why we don't see anything based on our current understandings. Some of you act like it's saying something it never did.

I love the theory that we will be the first or one of the firsts to colonise and fuck space and shit. turn all that scifi shit on it's head. WE'RE THE ALIENS!

[QUOTE=ForgottenKane;53100960]Finding other life indicates that life IS common which then increases the probability of a galaxy-wide civilization by a significant degree - but we still haven't seen one. Finding more life makes the probability of a "great filter" incredibly more likely.[/QUOTE] Life being common and us not seeing it doesn't even slightly imply that life is being wiped out by itself at a certain point though? It more implies that the universe is a big place, like we'd miss shit not even that far away relative to the universe around us. Plus any method of communication we have is likely to be unheard since they'd have to be in a very specific part of history, and that's if their civilisation even works on a system slightly similar to ours. I'm sorry if it seems like I'm not getting this, but a lot of what's said in this video seems like saying "2 + 3 = 5 and therefore ghosts exists". Like it just takes a huge leap for me, and I don't quite buy the leap. Idk.

I always liked the theory that life is everywhere, just the more advanced civilisations that found us are watching us in hiding to see if we'll either blow ourselves up or make a proper effort to leave our system, and once we do they'll make themselves known. Not even in a "guiding humanity towards prosperity" kinda way, more of a "making sure these are the right kind of fucks we want to populate other systems" deal.

[QUOTE=_Axel;53101575]At this point anybody in this thread who still claims something along the lines of 'we haven't seen multiple solar system spanning civilization yet thus there is something that destroys them before they reach that point' isn't reading the fucking thread. 1) We don't have the means to see jack shit outside of our own solar system, whether it's simple life on exoplanets, or interstellar civilizations. We just can't do that. We're blind. Any argument that deduces 'no advanced civilization exist' from the fact we can't see them is automatically bullshit. 2) Even if we could see everything and we couldn't find any multi-star spanning civilization, it wouldn't mean that something ends up destroying those civilizations before they reach the 'space' age. The simplest explanation is that colonizing planets outside of your own solar system is extremely hard to pull off. The assumption, again, is that technology grows exponentially while completely ignoring hard physical limitations, which is not realistic in the slightest. [B]Interstellar colonization may very well be impossible, and there isn't that much of an incentive to do so in the first place anyway.[/B] Occam's razor -> So-called 'dyson swarms' are either impossible to construct, impractical, or extremely hard to pull off. End of the 'argument'. No 'Great filter' necessary. LMAO. Not even close. Another 'technology grows exponentially guys' bullshit wankfest. [Citation needed], [B]can anyone here prove that interstellar colonization is indeed possible at all?[/B] The 'Goldilocks zone' doesn't guarantee the development of life at all, let alone advanced civilizations. It's just [I]minimum requirements.[/I] It's your understanding of life that's wrong. [I]Yet another[/I] baseless assumption. Or we don't see shit because we don't have the means of seeing shit. We can only see if there's a massive object in a nearby system [I]if we're lucky.[/I] That says nothing of life or civilization. EM waves with a comparable power to ours are undetectable outside of their own solar system. We just can't see shit. Or we just can't see anything at all given our current technology. [I]Again,[/I] the only thing we can measure right now is whether a [I]massive[/I] object goes in front of a star at some point. Not really something that gives us the exhaustive characteristics of the entire star system. But statistics don't tell us whether there's life or a civilization in the goddamn [I]shadow[/I] we study. We don't have the tools to tell whether those planets are populated. Quit making baseless assumptions. 10^6 time 10^-15 isn't very much. The point being, [B]we don't know how probable it is for basic life to transition into advanced civilizations.[/B] You mention statistics, yet the only data we have is our own civilization, which isn't representative of the entire universe [I]in the slightest.[/I] Every single value in the Fermi Paradox is made up. Nope. The so-called 'Fermi paradox' is just a concept aimed at sci-fi nerds which is built out of ludicrous assumptions that are based on basically nothing. It's even more hilarious that people bring up 'statistics' when every. Single. Probability in the equation is basically made up.[/QUOTE] You just listed 3 filters yourself, with the last one being behind us. Fermi paradox itself isn't bullshit, the assumptions people make are. Every objection you have with it, could be a part of it. [QUOTE=_Axel;53101575]The 'Goldilocks zone' doesn't guarantee the development of life at all, let alone advanced civilizations. It's just [I]minimum requirements.[/I] It's your understanding of life that's wrong. [I]Yet another[/I] baseless assumption.[/QUOTE] You're missing the point. If goldilocks zones allow for life to happen and existence of life allows intelligent life to develop then by the pure chance in some of these zones there should be intelligent life older than us. Nobody's arguing that there's going to be life in every one of them.

The goldilocks zone doesn't make any sense. It's a [I]prerequisite for us[/I], as in lifeforms with human physiology. How do we know that there's not other forms of life out there that are Sulfur or Silica based? It's easy to say something like that is impossible when the [I]only[/I] form of life you've ever observed are all Carbon based. The only reason our concept of "life" is given these requirements (liquid water, goldilocks zone, etc) is because we're assuming all life will naturally develop into a similar physiology. Considering how absolutely fuckhuge large this single galaxy is, I find it highly unlikely that there's no conceivable way for ANY OTHER simple lifeforms to exist, be them carbon based or something entirely different to our definition of organic life. More importantly, even if only 1% of all the planets in the galaxy are ideal for carbon-based life, that's like 100 quadrillion planets. Maybe not exactly that but it's a [I]massive number[/I]. There's no fucking way that out of all of that, Earth is the [I]only one[/I] that managed to develop carbon-based lifeforms.

[QUOTE=Silly Sil;53102532]You just listed 3 filters yourself, with the last one being behind us. Fermi paradox itself isn't bullshit, the assumptions people make are. Every objection you have with it, could be a part of it.[/QUOTE] The point is it's irrelevant to make up explanations for the absence of visible alien lifeforms when us being blind is the limiting factor anyway. [QUOTE]You're missing the point. If goldilocks zones allow for life to happen and existence of life allows intelligent life to develop then by the pure chance in some of these zones there should be intelligent life older than us. Nobody's arguing that there's going to be life in every one of them.[/QUOTE] No. It won't happen by 'pure chance' unless the probability is high enough.

[QUOTE=Weirdness;53102372]I always liked the theory that life is everywhere, just the more advanced civilisations that found us are watching us in hiding to see if we'll either blow ourselves up or make a proper effort to leave our system, and once we do they'll make themselves known. Not even in a "guiding humanity towards prosperity" kinda way, more of a "making sure these are the right kind of fucks we want to populate other systems" deal.[/QUOTE] By the time your civilisation has gotten to the point of being able to hide itself you've already emitted so many signals into space with reckless abandon that you wouldn't be able to do it. Look at us, if we decided to hide ourselves what would we do about the insane amount of information we've already broadcasted? You couldn't. You would literally have to decide against using radio when it was first discovered. Good luck doing that in the late 19th century trying to argue radio transmissions aren't worth it because there's a chance it could alert an alien civilisation... More info: [video=youtube;tEBn8bc0k-I]https://www.youtube.com/watch?v=tEBn8bc0k-I&vl=en[/video]

[QUOTE=E1025;53105060]By the time your civilisation has gotten to the point of being able to hide itself you've already emitted so many signals into space with reckless abandon that you wouldn't be able to do it. Look at us, if we decided to hide ourselves what would we do about the insane amount of information we've already broadcasted? You couldn't. You would literally have to decide against using radio when it was first discovered. Good luck doing that in the late 19th century trying to argue radio transmissions aren't worth it because there's a chance it could alert an alien civilisation...[/QUOTE] Nope. The 'our TV signals are broadcast in the whole milky way' trope is just an urban legend. The vast majority of the radio signals we emit don't even make it beyond the edge of our solar system before becoming noisy gibberish. The rest is signals related to space exploration which don't make it to other stars either. You think we'd be using massive dish-equipped antennae aimed in precise directions to pilot our probes if something as feeble as TV signals could make it to incredibly more distant star systems and remain recognizable? On top of that, EM waves amplitude follows an inverse square law, which means that if you increase the distance ten-fold, the amplitude of the signal is reduced by 100. The radius of our solar system is approximately 5E15m, and we already have to make significant efforts to broadcast recognizable signals to that distance. The closest star, Proxima Centauri, is 4.22LY away which is equivalent to 4 million solar systems chained together. Our strongest signals would thus have their amplitude reduced by a factor of 6E13. At this point the radio signal is simply drowned by background radiation. So the whole radio signal reasoning is bullshit, our galaxy could be teeming with radio age civilizations and we'd be none the wiser.