Can We Solve Fermi's Paradox? with Dr. Duncan Forgan

what do we do when and if we discover alien life in one instance we already know because it happened and then it didn't in 1996 none other than then President of the United States Bill Clinton announced on the South Lawn of the White House that evidence for microbial life on Mars had been found in the Allen hills 84001 meteorite in the form of what appeared to be microscopic fossilized evidence for a short time the public believed that alien life had been found then the results were called into question by other scientists and to this day it's not settled as to whether that and other meteorites of Marchen origin carry evidence of past life on that world what was interesting was the public reaction everyone just seemed to say well there it is and moved on we often think that the discovery of life on other worlds would be a Titanic game-changer for Humanity but for much of the late 19th and early 20th centuries it was a household belief that Mars was inhabited by little green men building canals this was even erroneously backed by some of the scientists of the time such as Schiaparelli and Percival Lowell only when Orson Welles scared the daylights out of some with his broadcast of his version of HG Wells's War of the Worlds did Martian life become a public problem but even then not as many reacted badly as is often portrayed but what of an advanced alien civilization what if we spotted a techno signature say a giant Dyson swarm built by someone so powerful that our technology seemed like sticks and stones in comparison what if it were a machine civilization so divorced an experience from our biological reality but it's difficult to even comprehend it would society react the same way or would it be Orson Welles all over only this time it's real you have fallen into event horizon with John Michael Gautier [Music] [Music] [Music] in today's episode John is joined by dr. Duncan Forgan Duncan was a postdoctoral research fellow at the school of physics and astronomy of the University of st. Andrews his research focused on numerical simulations of protoplanetary discs he is especially noted for his research into numerical astrobiology he has appeared in the BBC's stargazing life the sky at night and horizon welcome everyone to event horizon with me John Michael Gautier if you enjoy what you hear fall into the event horizon hit the like button and become an active subscriber by ringing the bell duncan Forgan welcome to the program hi it's great to be here now doctor correct me if I'm wrong your early work was on planetary formation a sort of a different model than the standard model that that's out there can you explain that yeah sure so my PhD work was on as you described an alternative model of planet formation so the kind of accepted model the model that explains the most about what we see in actual planetary systems basically requires you to start with a star and when you build a star one of the things you get as a by-product as a disk of material right of that star and inside that disk you have lots of gas and lots of dust and the dust grains inside that disk can collide and stick together and get slightly bigger and then collision after collision after collision you slowly start to assemble bigger and bigger things you go from dust to pebbles to boulders to asteroids and comets and then all the way up to planets and that's the kind of bottom-up approach and that's a very successful theory in explaining quite a lot of what we see but what we're starting to realize is that there are some planetary systems that don't really fit that picture very well and we're starting to see evidence of another type of but it's plant information but it's also low mass star formation so it's bridging that boundary before when a planet stops being a planet and becomes this intermediate category brown dwarf and this is a top-down approach so instead of trying to build your planets from little bus screens upwards what actually happens is the disk itself is so massive that it can break apart under its own gravity and these these fragments that come out are about the size well maybe three of four times the mass of Jupiter to start with at the very minimum something can be much much bigger than that still and the trick then is to figure out what happens next because this happens very quickly so in the accepted model of planet formation it takes you millions of years to get a Jupiter in the model that I studied from my PhD and for subsequent research you can get something that's five or ten times the mass of that in less than ten thousand years so this is a very rapid way of building quite large objects and in this alternative theory it might even be the case that some of these bigger objects lose some of their material and end up being smaller objects and if everything lines up and you're a very lucky body then you might end up forming a solid core lose your atmosphere and you might have something that's more like a super arathor or even potentially even an earth-sized planet at the end so a lot of my research in that area was to try and figure out though can we do that is this chain of events possible can you go from big discs to big clump of gas to small planet and if you can how often does that happen and the work I did showed that you can do it but it's not very common so the chances are that if you're looking at planets that are about the size of the air they're formed by the more accepted model of planet information is it possible that both models might be correct and that you have situational situations within the discs that can be different so one of the last things that I looked at in recent times and I have a paper that's sitting in preparation and will hopefully be submitted at some point is investigating this very idea that the two formation mechanisms could kind of coexist in the same system and so at the minute it seems quite possible whether we expect to see lots of systems doing that and whether we expect those systems where it's all happening at once to look like what we see out there in the universe or not is a still a bit of an open grave it doesn't look like that's the case it looks like the planets that we see tend to be planets that are built purely using the accepted model and that the alternative model is more for building binary star systems systems with brand orfs in them and yet maybe the occasional oddball system that accepted models find it difficult to explain we have some systems with lots of giant planets at quite large distance and the kind of the standard theory of planet formation doesn't do very well with those whereas that the alternative theories do quite well so it could be a case of looking at a system and saying well chances are it's either gonna be this way or it's gonna be that way and most the time it's going to be the standard way but for all your odd balls and your difficult situations and your big systems with lots of stuff this alternative method is very useful for explaining those now is it is it possible to investigate this can you look at protoplanetary disks around young stars and determine if this is the case well excitingly yes in the last well even in the last 5 years we've really started to open up our understanding of the disks as they're forming as they're starting to evolve from their young state which is quite massive compared to the star so you've got a star being born and the disc around it and the star on the disk initially are about the same max and then not very rapidly changes the disk flows onto the star very quickly and the star builds up mass that this loses mass so you have this very short window in which this really unstable vast top-down model of building stuff can happen the problem with is that this stage is usually when the entire system is enclosed inside a big shell of dust and gas it's still falling into the system so your usual approach is using say visible light and even sort of the short and for red light find it very hard to penetrate so you want to go to nice long wavelengths and reappear in then then the challenge with that is that you peer in that long wavelength but you don't have the ability to resolve what's happening all you can see is kind of blurry images and it's really since well yeah in the last 5 years I would say when we have systems like Alma which is a very big interferometer that's working with these longer wavelengths that gives us the real sharp resolution the clarity to see what actually happening and so we can see these desks aren't just disks they have lots of structure they have rings they're spiral arms they have what looks like warps and we can see planets being born in the system so you can see the beginnings of these objects and it's really the first time we can stress test these theories and say right what's really happening here what's what's the observational evidence for these theories that we've been cooking up you know on paper and in the computer for you know the last 15 or 20 years now we're really putting them to the test that was that was your original work but since then you've also moved into astrobiology what sparked your interest in going in that direction well it was kind of it was coeval we were I was doing work on planet formation and astrobiology at the same time as a PhD student in Scotland we were required to take some courses to kind of fill up the first year of our our degree just to have some top material as well and I took some courses on astrobiology and I took a course in SETI as well it was a bit of a rarity at the time time of course it's specifically focusing on sati we were quite lucky in that regard and the subject got me very interested and clearly it was very relevant to exoplanet science because if you want to think about life in the universe you need to start with the habitats and as far as we can tell planets are among the best habitats for producing life at least we live on a planet it's a good place where you can have stable chemistry the temperature can stay roughly the same you can be shielded from all sorts of radiation nasties with the right atmosphere there's lots of things to to recommend a planet as a life hosting object and then SETI itself looking for intelligent life kind of demands you to be even more focused on where life can be you know we look at microbes and look at extremophiles which can survive in these really what we consider very hostile environments high radiation high temperature high salinity low temperature low salinity all these environments where humans would perish in minutes we have organisms surviving if we're looking for big animals with big brains then that really focuses the limits of life to something even narrower you know the hatful zone in that sense the range of temperatures we can survive in a even more than it would be for one of these crazy organisms so it really pushes your focus and during that time I was thinking about how exoplanet science should affect our understanding of intelligent life and how we haven't really figured out how to incorporate our knowledge about exoplanets into the question of how many planets we expect to have intelligent life on straight away I came up with some ideas it's hype to work in these ideas in Vanessa disco kind of way build a model that sort of lets us run an experiment in the computer saying here's a milky way with a population of exoplanets that Luc's statistically like our Milky Way if we make some assumptions about how intelligent life appears what happens you know and how does changing our assumptions change the answer and kind of just exploring the hypothesis is aware so that was actually my first paper which is a bit unusual for somebody in my field to to take what was a bit of an oddball subject and have that as their first publication but it was a really interesting idea and it got a lot of press interest and it was my first exposure to well doing the press junket really being in a press release and then having to you know do lots of interviews and speak to people with various ideas about what your work said and what you weren't meant and it was very odd you know I saw my work been discussed and the editorials were quite big newspapers and they were putting some weird political spins on it and it was very very unsettling so it was a really big learning curve for me and I learnt a lot about what you should say in a paper and what you should say in the newspaper and how they said can sometimes be the same thing and Hadley can sometimes be separate things and yeah it was it was quite an experience it was a baptism of fire a baptism of fire but that's the media you know the media is not when reporting on science they are not always 100% accurate or 100 percent ethical in some cases well that's that's that I discovered yes but now astrobiology is it used to be considered pretty fringe but not so much anymore because I think were you know through the efforts of the SETI programs which are legitimately looking for signals and through the efforts of scientists writing papers it's a little bit more legitimate of a question now to ask are we alone but unfortunately we get into this this pop cultural gray area where people talk about the UFO phenomena not all that do you think there's any possible validity to that as regarding UFOs I haven't seen anything that would make me consider that the evidence was pointing towards something extraterrestrial I think one of the things that I've discovered in my research of not just the search for intelligent life but also some work I've done in the last few years on propulsion and in stellar travel is that it's really hard really hard and if you want into transport biological material very hard if you want to transport walk-and-talk in aliens really really hard and it seems I mean you don't want to say impossible but extremely extremely unlikely that these accounts that you see of UFOs landing of people having close contacts Close Encounters of the Third Kind or whatever you want to describe it there is very little evidence that you can trust these accounts and that's not to cast any aspersions to people that have these experiences they're presumably very genuine experiences and that they wouldn't say these things and he didn't believe them to be true because they're quite fantastical and weird you wouldn't say something like that unless you believed since usually that this is something that happened to you but extraordinary claims require very extraordinary evidence and in the cold light of day I have not seen an account that is ironclad to say this is proof that we are not alone in the universe and that there are aliens visiting the earth there's nothing that I can point to that says this makes me consider that as a possibility I've seen nothing either you mentioned something interesting you you mentioned that space travel interstellar space travel is extremely difficult now could that be a viable solution of the Fermi paradox that it's simply just too hard and no one colonizes galaxies because you just have to work with what you have and your your own star system is that is that a viable solution okay so maybe I should quantify that interstellar travel with spacecraft above a certain size is very hard interstellar travel with spacecraft below a certain size becomes increasingly easy and now what's worrying about that is that it makes the Fermi paradox quite strong so you can imagine a situation where maybe not far in the future of humanity maybe 100 years maybe 200 years we could start launching spacecraft that have enough instructions on board to create copies of themselves if they travel to another star system and make a copy then you go well you now have two probes those to travel to another star system you know four probes and so exponentially you start to grow this fleet and some work I did a few years back with a student of mine should that if you have this kind of approach and you started with a spacecraft that could travel at a speed of Voyager which is a snail's pace right it's you know a hundred thousand to the speed of light it's not fast compared to the speed of light if you started at that speed and all you did was use the gravitational fields of the stars you visit so basically doing slingshot maneuvers like oh I did it to get out of the solar system you could a you could build the speed of those spacecraft up two by one to five percent of light speed which is a lot better and you'd have loads of them so you could potentially explore the Milky Way within ten million years that is a heart beat compared to the age of the earth which is you know over four billion years so that really makes you think okay if the earth has been run for such a long time and there have been many intervals of ten million years in that time where are not particularly advanced civilization the only things you have to figure out are how to make copies of small things and how to program the computers to navigate autonomously and to be fault tolerant even under high radiation which these don't seem particularly instrumental challenges if you can do that then within ten million years you can have a probe around every star in the Milky Way now can you can you maintain that sort of threw like a diamond can you maintain that for indefinitely for millions of years if your probe can repair itself Roark does it to touch on your more recent paper does it eventually go corrupt and just stop working or do something so yes so to look at my more recent work one of the objections to this is that as you keep on making copies and copies you're going to introduce errors into the copying because your machines are getting struck by cosmic rays and you know bits in the computer again flip from zero to one and some of these mutations will be benign some will destroy the spacecraft and make it inoperable and some will changes its behavior in the same way that small changes in the DNA the genes of animals can cause natural selection and it can cause evolution and the argument is that maybe eeveelution would then happen in these machines and the easiest way for a machine to make a copy of itself is to take another machine and take it over and basically salvage it for parts and this is the same behavior that predators have was prey right he tried to eat spree get protein builds up its body in this case it be a predator probe take spray probe dismantle say and use its pieces to build another copy of itself it's the same rough function but there you go and the argument could be that well if this happens then the Predators basically eat all the prey and the number of probes goes down a lot and therefore that's why you don't see signs of probes say in the solar system or in any other star system because all the probes have been eaten right so the Predators have eaten all the protein than the population collapses because it runs out food supply in this so this would be a natural wealth not natural and that's in in a normal sense but a natural ending of a colonization using pondan probes right right so it would mean that the the program that you designed into the machines it's no longer the program they're following right and as a result you may not have as many probes doing the exploration they may be going in the wrong direction you know if you've got a planetary probe and it's looking and saying my next target is meant to be there but I know there's a whole bunch of prey back in that star system I've just visited I'm going to turn around these things can kind of stop the exploration process they can make it take longer or it can halt it entirely and so this is one objection to this idea self-replicating probes can basically explore the whole Milky Way so quickly that we should see tons of them and we don't and so one of the solutions is the reason we don't is because there's lots of predators and they eat the prey and there's not as many it's sort of scary if you think about it because if we start sending out and breakthrough starshot or something we start sending out micro probes and they start disappearing then there could be something pretty and being a predator against them out there now it's the other thing about this is that when you begin to start harvesting raw materials of star systems to build these primitive probes Carl Sagan years ago pointed out that you could basically consume a large fraction of the galaxy by sending out a fun women probe so I guess also your concept would explain why that hasn't happened why you know the half the galaxy hasn't been converted into fun women probes and it doesn't appear that any fraction of it has been I guess it would peripherally also solve that's that question to you right to some degree I mean if if there is no evolution at all in the program and every probe visits every star and you have a sensible end point which is once everything's been explored sit still then you wouldn't have this issue of you know everything being converted into probes and that you'd lose all the planets in the minute they got Milky Way to you know there's this kind of exponential eating process if something went wrong and there was evolution but in in a negative direction if that's such a thing then yes you could find that maybe the the reproduction goes out of control we have a similar concern about nanotechnology on the earth and that if you produce self-replicating nanoprobes that say use carbon to make copies of themselves then if something goes wrong with the programming and they go out of control then everything that's carbon gets turned into probes including us right and they call this a gray goo scenario because the entire planet surface gets turned into gray goo and again there are people who are thinking about this carefully and there are people who have come up with precautions and protection against it doesn't guarantee will never happen but at least people are thinking about it so I would assume that if somebody was smart enough to send a von Lohmann probe out into the universe there was about these things carefully - and in fact this is actually one of Carl Sagan's favorite objections is that the dangers of sending probes like this are so high the civilizations would agree not to send them ever again or at all so the reason we don't see them is because they're so dangerous that they could convert the entire Milky Way into probes that no civilization with any sense of moral judgment would do so so that I guess would involve another solution of the Fermi paradox which would be Gazoo hypothesis where they just sit there and wait watching no contact until you start building something like seriously advanced artificial intelligence or a fine women probe and they that's when they step in and say you can't do this you you have to make sure the rest of the galaxy is protected now you could also get into a situation to where you if you have multiple civilizations in a galaxy and they're all producing anointment probes that are eating each other then it becomes a sort of psycho monment cold war essentially mm-hmm yeah well this is the thing and the problem is that the minute you launch that probe because it's quite hard to travel at any decent speed with people on board you're not really in control so the conflict will then take place without your orders and if the conflict lasts a long time that conflict will trigger arms races in the probes and we see when we have both predators and against the same prey in ecosystems on the earth we can see how the predator has changed their strategies to suit themselves to ensure that they propagate further so we could have some very unintended consequences of these kinds of actions Suns increasingly dangerous even more dangerous than I thought the constant might originally be especially if you start involving advanced artificial intelligence in the probe then you know well this is the thing by doing that I'm going to make the probe even more complex meaning that more could go wrong you know again like you say the cosmic ray exposure or anything like that can just cause it to become essentially a galactic monster and attacking everything it can for resources but thankfully this does not appear to be the case we see no evidence of this when we look out into the and the galaxy now what are their what is your gut feeling on the Fermi paradox was the actual solution well I mean I've spent a long time thinking about it and I have a book that's out through Cambridge Press and it's called solving Fermi's paradox unfortunately I don't actually solve Fermi's paradox in the book all I really do is list the solutions that I can find and think of and I came up with think 66 distinct solutions and they kind of fall into three categories so they fall into the category of well maybe intelligent life is rare the second category is that may be intelligent life doesn't last very long and then the final category is that may be intelligent life is very hard to see and into this last category a lot of interesting stuff and kind of kooky crackpot II stuff falls in as well so you know this is where the UFOs live and the men in black and the ancient astronauts and all the stuff that is you know quite rightly pooh-poohed by scientists so my feeling is that the answer if there is an answer out there is probably some mix of the first two it's probably the case that intelligent life is actually quite difficult or it's simply rare it requires a lot of luck when you think about the the various contingent circumstances that have occurred on the earth to not only produce life but to produce life reproduces sexually that has relatively large bodies large brains and then the fact that there was you know at some point there were six species in the genus Homo now there's only one why was it us what did we do to earn that particular distinction of being the survivors what were the circumstances that drove humans to continue to dominate their surroundings interface to cover the entire surface with their population it may well be the case that you know as I think of Stephen Jay Gould said if you rewind the tape and play it back you'll get a very different answer and if you whine the tape back far enough and play again humans never really appear as an intelligent species you know it's really not clear to me that it's the case that humans were protested in any way to be intelligent I don't think it's the case that planets that are around for long enough with life make intelligent life I would be surprised if you went out there find planets with life had been around for you know maybe twice as long as the earth that had showed no signs of even producing you know relatively large animal life let alone intelligent life so my feeling is that intelligent life is hard and also it's probably nasty brutish and short to quote Thomas Hobbes we're not very good at looking after the planet it's pretty obvious for not climate change is a problem the the fact we still have an awful lot of nuclear weapons is a problem our research into all kinds of technology with existential risk is a problem there are lots of possible ways that we could just end ourselves and it's not clear to me that we possess the wisdom as a species to get past all of them so if that's true for us then that might explain why we don't see any signs of intelligent life right there that they struggle to become intelligent and they struggle to survive and on that we have to take a break I'm joined today by dr. Taunton Forgan and author of solving Fermi's paradox we'll be back in a moment if you're new to event horizon it's subscribe it's free and we upload videos every Thursday plus additional content and we're back with Duncan Forgan now there's another possibility too that's related to the idea of rare intelligence also it could be that earth itself is incredibly rare and that just the right factors were present for this this planet to produce life and intelligence at all now what sure what are some of the factors that that contributed to the genesis of life on Earth well there are lots there's the fact that we have a planet that has a relatively large amount of surface water we have an atmosphere that's thick but not too thick in terms of producing life some of the things that we need to have is a suitable background in which to do the right chemistry and essentially one of the things you're needing there is protons and electrons to move in the right direction you want the right chemicals you want a good dose of sunlight not too much not too little you want a bit of ultraviolet light not too much not too little and if you mix that all together and wait long enough then maybe something happens but the key thing really is stability you know you need relatively quiet conditions for life to form now we know that on the earth the minute that things settle down we started to see in the fossil record signs of life it's not clear that that was going to be the case we can't use the earth as a single sample and say that's what always happens that the minute that life can arise it does that's not necessarily true just based on one sample but it certainly is clear that there's there are certain parts of the Earth's history where life can't arise and what we're seeing in the exoplanet systems that we know about is that that earlier part we called the Hadean period because it was literally hell on earth we see hell on other planets and that hell is not going away you know we see planets that are basically entirely lava on the surface we see planets that don't have a surface we see giant planets that have punishing conditions in the upper atmospheres we see lots of planets that are not habitable we also see lots of planets where we have no idea you know it's really important to note that when we look at a press release about an earth-like planets what they're saying is is that either the mass of the planet is close to the Earth's mats or that the radius of the planet is size is close to the outer radius and they might even be lucky and be able to say something like the surface temperature of the planet based on a few assumptions is somewhere in the range between zero and a hundred degrees Celsius now a lot of these stories you hear all we know about these planets is either their mass or the radius we actually don't know much about the atmospheric composition it's really hard to figure out what their composition is and we can do it reasonably well for more giant planets it's taking a lot of effort to push that technique down the size scale into something that we'd regard as a terrestrial planet so the word habitable gets use a lot I don't think we should because a lot of the time when people say habitable what they mean is warm they mean it's in the right temperature range but really habitability is a very complex concept and it's not just about temperature it's about you know the water availability the pH of the water its activity what what electrons are floating in there what the chemical mix what's the magnetic field you know and this is one that we we know about as a problem for astrobiology but we find very hard to probe for exoplanets it's really unclear well how we'll ever find out how a terrestrial planet has a magnetic field at all and if it doesn't then that planet is missing an important shield against very harmful stellar radiation and the techniques we have tend to point our focus towards planets going closer to the star so planets going around smaller stars but orbiting closer to the temperature remains climate quote-on-quote if these planets sorry if these planets don't have a magnetic field then there's no chance these things have any way from them whatsoever now this leads to something that's been in the literature it's been popping up a lot lately this idea of detecting bio signatures by characterizing exoplanets as we get better equipment like the James Webb Space Telescope whenever that finally happens do you think that that's gonna the landscapes gonna change and that we will be able to tell more about these exoplanets as as time goes on or is it just probably not going to ever be on the table for us to detect life at a distance well I think the biggest sort of truth in this area is though you know astronomers can be looking at spectrograph for an observation and they're gonna see a characteristic line and they're gonna go Eureka I've detected like what's probably going to happen is they're going to see some lines and spectrum and go hmm that's interesting and write a paper saying look what I found isn't it interesting and there's going to be a slow build of evidence and it will take quite a bit of time I don't think you'll be able to confirm with one observation or even a handful observations if a planet is inhabited it will take decades and I think one thing that we're gonna have to be careful about is how to keep the public engaged with a story that takes a long long time to reach its end and what's going to be quite difficult is that we're gonna see this story of progress from hmm that's interesting - oh actually it's a false negative it's a false positive that thing we saw which we thought was signs of life is action geological activity will may even have the more frustrating opposite thing which is the false negative when we look at something and say that that's not just probably not biological but with later observations many years in the future we can go back and say oh no that wants biology we just didn't see it properly so I think the idea that most the public have in their hair does how this is going to work isn't what's going to be the reality there's not going to be a Eureka moment there's going to be a moment where the probability of this planet being inhabited goes up a little notch and then more observations happen and it goes up another little notch and then more observations happen this goes up another little notch and I'll be a slow agonizing climb up this ladder of probability from a few percent to 70 to 80 percent and we might not get much higher than that at that point all we can see is we're 80% sure this thing is is inhabited that might be good enough for some people it might not be good enough for other people some people might just say well look you can't say that you can't say it's 80 percent inhabited or you can't say it's 80 percent sure you've got to be very sure you've got to be you know 99 percent sure which is you know something more approaching the scientific standard for sure you know but we detect the Higgs boson for example it's not 80 percent certainly detected its 99.999999% detected right I think we might struggle to get to that level of absolute certainty for life on other planets especially if they're outside the solar system that leads to you know that that's a somewhat of a problem for a lot of areas within astrobiology is the ambiguity of something if just because you see oxygen and methane and exoplanet atmosphere does not necessarily mean there's a biosphere down there it could be created by different mechanisms and it leads to I think you're right and in that as we explore this stuff it's gonna be really ambiguous the bio signatures with a few exceptions I mean if somebody sees what's clearly a vegetative red edge or one of those types of bio signatures maybe it might be different but this is also a problem study too because I think the public thinks that that you're gonna detect a signal with a message in it and no that's probably not going to be what happens it'll probably be somebody's radar or some communications internal to them that we can't ever decode do you expect that we'll ever have an unambiguous answer or have any kind of information about an alien civilization itself looking through SETI or will you just forever say radar well to go back to your point about the red edge that are false positives for that as well which is kind of sad there are false positives for everything so looking for a techno signature looking for a sign of Technology is a slightly surer bet because technology does things that natural things don't so if we were looking for you know for a signal and even if the signal doesn't contain information the nature of the signal itself will tell us something about who's sending it whether it's being sent by you know a spinning neutron star or being sent by a radar system or being sent by a transmitter so yes the public are probably slightly disabused of the notion that yeah we'll get a signal and or contain the prime numbers like it did in contact or something like that the chances are that what we will see will be something like static if you're encoding your information in the most optimized and efficient way possible and the person on the other site doesn't have your encoding system it will sound like static okay that's a fundamental theory of information theory so it may be the case that we see something it looks like static but the fact that it's being transmitted on a very specific set of frequencies and that it's very powerful might give us some indications if it's coming from a planet then that planet is going to move around its star and so we're going to see the Doppler shift of the signal as the planet goes around the star that might be a good indication that's coming from a planetary body that might give us some some hope that we can understand that but yeah after that we start to struggle you know we've got to be careful that what we're looking at is it being generated by the earth and being bounced off something else which is almost always the case when SETI searches find something they find a signal and go that's very narrow in frequency and it's very strong and they find it's a signal that's come off the moon or it's coming off a satellite or something and it's actually a terrestrial signal it's one of ours so yeah there are limits to what you can do on the other hand if you're looking for an apps techno signature so you're looking at an exoplanet and you look at its atmosphere and you see certain lines in its atmosphere you may have that Eureka moment because technology can produce things in the atmosphere that nothing else can most notably CFCs as I recall - right so if you see something like a CFC in the atmosphere that's produced in factories right so if you see CFCs you see factories and if you see factories something has to build those factories so there is some form of of of intelligence building those factories and it seems to be the case that if we use the James Webb and we picked some very odd-looking stars so we picked a white dwarf which is basically a dead star and looked and we find a planet going around it then the nature of the white star spectrum the white dwarf spectrum is such that we be able to detect the CFCs and in that planet's atmosphere and that would be conclusive proof that there's a dirty species over there so there are signatures like that there are some other signatures that might give us some indication that there was a civilization there so a few years ago some colleagues of mine we got together and we wrote a paper about this and looked for the ways that we can see dead civilizations and some of the things that we thought about in-house civilization could kill themselves leave quite specific spectral signatures and if we're lucky and we're looking at the right time we could see signs of that in their atmospheres and that would be proof again that something lived but it would also say that something died I remember that papers that also had in it as I recall rotting vegetation producing unnatural amounts of I wasn't my thing it was a methane by-product so there are certain byproducts of rotting vegetation that just don't exist even in you know your standard geochemistry and they're quite strong we've got quite nice drum lines and they persist for quite a while so if there is some kind of pandemic virus that killed all life on this planet there appeared an interval where if you're an alien looking at the earth you'd see this huge spike in this particular line and that line would tell you okay there's a lot of rotting dead stuff there so it's grim but that would be one way we could see yeah it has sign to life so could it might actually be signature of mass extinctions so if you're having you know like one of Earth's past mass extinctions and maybe you might see the effects of it in the atmosphere perhaps mass extinctions are harder because they take a bit too long so you know natural mass extinctions take quite a few million years to run their course and so this the die-off is slow if it's human caused we're doing a hell of a lot quicker so yeah that that's potentially possible I mean to me the stable strong you want to basically kill everything within a year and to do that requires like a calamity it requires something pretty serious could an asteroid pull it off sufficiently damaging asteroid impact or would you just not see it at all I mean because of the atmospheric effects of the asteroid itself I think you'd be missing it from the fact that the asteroid itself would just cause a nuclear winter and produce you tonight's of obscuring dust so you'd be hard-pressed to say that was a living planet hit by an asteroid as opposed to that was just the planet hit by an asteroid and to some degree that's the same kind of effect you would see if we activated our nuclear weapons at once which is another way we could get rid of ourselves they look a bit like a like a weak asteroid impact a lot of the same features would be there the radiation byproducts wouldn't really give us much to see so again there are certain things there are signs of potentially dead life or stupid life if you like but these can also be confused with really natural phenomena that can produce you know huge amounts of energy when they smack things pretty hard so would it be possible let me ask you this because I know that nuclear weapons have characteristic double flash emissions and things like that could you detect that at a distance if you just happen to be looking at a planet when it was undergoing a nuclear war could you detect that or would it simply no not it wouldn't so we try to calculate that and it seems to be the case that even if we detonate everything at once in the same location and it was we're beaming the radiation in a certain direction it'd be tough to get that outside of the solar system you'd have to be probably within the orbit of Saturn to see it I think that was the calculation we came to in the end so the double flash thing is good if you're in low-earth orbit it's a great way of detecting nuclear explosions but it doesn't travel far enough it's just not strong enough yes I recall the Vela satellites back in the 1970s did specifically that is just searched or nuclear testing through the double flash now one last thing I wanted to ask you about this if you're if you're looking at at a civilization that that has destroyed itself hmm might that imply that one of the other solutions of the Fermi paradox is correct and that civilizations simply almost always destroy themselves and that the rule is is that technology is always deadly to a civilization do you think that's there's an evil iddat e to that well I think this is partly why I'm leaning towards is the fact that when you look at at biospheres without intelligent life in them the biosphere is maintained a certain level of balance you know okay natural disasters can disturb that balance but it will restore that balance eventually over time they might take millions of years when you look at biosphere it's where you introduce intelligence there's a huge instability in the environment mainly because that intelligent species is destroying its resources when we talk about things like climate change and there's a lot of discussion here in the UK about the right words to use whether its climate change or a climate breakdown or whatever you want to call it I call it human habitat destruction because that's what it is if we're destroying the habitat but rather than just destroying the habitat of animals but it's drawing our own habitat and so it leads me to think that maybe intelligent life finds it very hard not to destroy its own habitat because that's not its end goal if you like it end goal is to produce as many copies of itself as possible the way it can do so the way it can cheat the biosphere you know we can use technology to close ourselves to feed ourselves to propagate ourselves in ways that nature cooked on quota never intended I wonder if that's a common trait and that whether it's a very specific disaster like a war or just the fact that we don't really have the wisdom to be stewards of our own environment it may just be that intelligent life is short lived and that was one of the reasons we went looking for science in our business paper was this idea that well if that's the reason we don't see anything out there how do we test that theory and the way we test it is we look for the debt and if we can find ways of looking for the dead and we find them a that tells us something about our existence in the universe ie were not alone there was at least one other civilization and the results the other thing it tells us is a rough guess a very first estimate on the shelf life of humans what's the future of our species it might also give us the wisdom we need to maybe avoid some of these obstacles if we can see other civilizations dying of climate change or dying of nanotechnology or genetic engineering or of the gray goo nuclear war you know the list is huge if we can see these things happening out there in the universe can we learn from their mistakes that would be probably the most valuable thing that could ever come from learning if intelligent life actually exists is to see what what ended it as opposed to something far more scary like you know you're you're looking out and you you see a machine civilization there's something that is indifferent entirely to you but it's just so all-powerful that there beyond its building Dyson's these swarms around Stars and everything else that you could to have no defense against it if you ever got its attention which brings on the question what are your feelings on if we got some sort of a message of communication or we saw a beacon you know something that's just blasting out narrowband emissions at 1420 megahertz and doing it in a way that has to be of alien origin should we contact them should we do anything proactive or should we just quietly watch what do you think is the safest or smartest thing to do well I mean I know the community is extremely split on this and that I think you've had guests on you're sure they're very much yeah hi let's talk I'm very much in the let's keep quiet category I think we have a lot of growing up to do to species I look at human humanity is a bit of a teenager that doesn't know how to clean his room is it really time that we go to the bar and socialize with the rest of the universe I don't think so I think we've got some work to do I think it's important that we listen not be watched not be pay attention but I don't think we're in the right place to actually start shouting at the universe and ultimately you know if there are other civilizations out there and they're looking at the earth it's there's a good chance that if they look at us they'll see a very interesting picture and we'll see lots of bio signatures together in the same place and that tells us you know if you see one bio signature you might think oh that's just geology if you see six then you start to build a picture of where that comes from and the chemical reactions and the cycles and when you do that and you come to the conclusion oh this is biology that's chlorophyll that's photosynthesis going on down there that's signs of active ocean life down there yeah okay I'm starting to build a picture of this planet inhabited and if you really stare us with your most powerful telescopes and you're not too far away you might start to see our radar chatter you might start seeing some of our TV emissions all sort of pretty weak there's a good chance they see us anyway right if they can tell that we're here and they're that advanced and they're not miles and miles away if they're within you know 200 lightyears right which is next door galactic Lee speaking but they're with Internet light-years they can see us you'd better hope they're not I think that's my answer yeah absolutely absolutely and we have to take another break I'm joined today by dr. Duncan Forgan author of solving Fermi's paradox back in a moment and we're back now doctor that we were talking about something interesting that that civilizations could destroy themselves and they they have may have a very short shelf life you know we've only had civilization for a very short time in the geological sense wouldn't that also be a solution that you know you just don't ever exist at the same time as another civilization in order to detect them directly so if you look for dead civilizations or even this idea of EXO archeology looking for essentially aliens remnants how likely do you think it is that that would be detectable within say twenty years do you think we're gonna have the instrumentation to really start looking at that or is it just something for the future so the work that we did in looking for the dead civilizations we focused on the recently dead I mean we looked at the first century after you know whatever Cataclysm had befallen them and the signals that we were looking at didn't last much longer than a few decades and some lasted only a couple of years so detecting the recently deceased is gonna be hard because you you know as you say you've got to be looking at the right place at the right time given the fact that your two civilizations may be separated by a great distance and the light takes some time to travel so you know you've got to be quite lucky in terms of archaeology unless they're building very big structures it's quite hard to accept that we can see buildings and other planets and if their ribs or if they're half buried that makes it even harder if they're building large structures in space potentially a lot easier if they're building you know Dyson Sphere shapes or partial Dyson spheres or anything like that then that obviously has effects on how the star looks to us and these are things were very good at spotting so the techniques we use for detecting exoplanets we could easily use for that and in fact it's a bit of certificate for free effectively whenever we do your study for exoplanets we're doing a quick piece of SETI as well to kind of cover write them or you know crazy ideas that maybe there's a giant space structure there and if it was there roots here so my feeling is that the signatures that we were looking for on the planets if it if it's thinking about on planet it's not for the current generation of technology it's probably not for the next generation like James Webb it may not even be for the generation after that which is the successor to James we're blue foir yeah it could be some time in the future it's not clear to me whether we would see things in the next thirty years it may well even be longer than that now say something is found a lot of people are gonna say well the government's never gonna tell us about it if they do find it which is silly because it's not up to the government but what are the protocols what happens when a detection is made what steps happen after that what are the science is going to do so the protocols that follow detection and these protocols are assuming you're seeing like a radio signal or an astronomical signal essentially the first thing it's do is check you're working go and try and see it again generally speaking if you can't see a signal twice it's not worth talking about and if you can confirm that it's not you know a case of human error it's not an instrumentation problem it's you know it's a real thing you go and speak to your colleagues somewhere else and say I've seen this thing can you point your telescope at this point in the sky in check and if they confirm that then you ask more people and they go in check and as you build up confidence this thing is real you then have to go and inform various individuals of your discovery you should inform the UN secretary-general the the chair of the Committee on peaceful uses of outer space I think also gets informed and your your nation-state needs to be informed as well clearly at that point you should tell the government you've got something interesting the final stage I think once all that is done is that either notice to the public now this kind of laughable when you talk about it now because these protocols were written in the late 80s and then we revised partially in the early two-thousands but they are very much a pre social media set of protocols there's an assumption you can keep a secret for what would be like six months nope that doesn't happen anymore it's quite clear that if any major scientific discovery is made it's on Twitter the next day so you know the example I give is the first detection of gravitational waves by LIGO in I I was aware of that happening maybe six to nine months before the press release and I'm not involved in any of these collaborations right I just know the right people on Twitter and if you just read between the lines of a certain tweet then it is it revealed as a secret right so you know even in large collaborations where there's a very strong onus on keeping things tight and hashed out before you go public before you confirm the thing it's gonna get out so some work I've been doing the last couple of years is addressing this and thinking about how we should go about changing these protocols to be a bit more 21st century and to acknowledge the reality that you know the internet exists right which is you know a very good means of telling things and telling stories but also telling misinformation telling fake news telling lies spreading propaganda and if there's anything that will be a conduit for this is this kind of activity so it's really important we figure out what to do and it's important we protect the people involves because if you're a scientist who discovers intelligent life and there are people out there who cannot cope with the fact that intelligent life exists and they get your information off the internet and what they're gonna do you know the security of your person and your family could be threatened and we should think carefully about this it may never happen you know I personally don't think we're gonna see any signs of intelligent life I have a pessimist I still think we should search because it's a good thing to do even if you don't think you see the thing you should you should test it you should be an armchair philosopher you should go out and do the experiment you should observe but the fact that even though it's a low probability event if I'm wrong and if we do find something the consequences could either be catastrophic it could be amazing or they could be you know new people just be like oh what's the next story there could be you know absorbed with politics I know that my country is certainly very absorbed with politics in the minute so yeah it could well be the case that the this discovery that you and I would regard as epoch-making is a damp squib in the news okay it might not be it might be very important it might be a very big deal and so we should think carefully about how to protect the people who are responsible for that story how we protect the story itself and how we make sure that whatever we do discover is put to the good of all people in the earth and the advancement of science now I I'm sort of in the same boat in that I don't expect to see evidence of an alien civilization within my lifetime but that's not the only chance we have of asking ourselves you know answering the question is life on Earth alone and that's because we have quite a few ice shell moons in the solar system that have liquid water under the surface most notably perhaps Europa and of course in solidus do you think that the chances of there being something just even if it's just microbial under in the oceans of Europa Europa do you think that's a strong possibility or do you think it's probably not going to be the case I would say I'm somewhere in the middle like I would toss a coin it doesn't seem ridiculous to me that these things could be these moons could be inhabited the conditions of deep ocean of these moons is not dissimilar to the conditions the deep oceans of the earth we know that there are certain forms of life that just don't care about the Sun and don't need it as long as they can get energy from somewhere else that's fine and you'd open and shelters have energy sources that come from the tidal forces of Jupiter so yeah that that might well be it I personally I'm fairly ambivalent I think it's quite possible but I'm so I'm an astronomer first and a biologist second implying leaving a bell just at all so I'm I'm not sure I think it's quite quite possible I'm not sure if I would go on and see it likely or unlikely but it's a very exciting prospect because if that's true then there are presumably quite a lot of icy moons not just in the solar system but in all sorts of planetary systems and if that's the case then it could be the life on warm wet planets is actually the rare thing and that was most common in the universe is microbial or you know even larger forms of life and in these subsurface oceans it is somewhat mind-boggling if you think about it because we seem to find the possibility of subsurface liquid water and quite a quite a moons in the solar system and even an asteroid series may have a slushy ocean of some sort and if we found microbial life at any one of these and it's genetically distinct from earth life and didn't you know hitch a ride there or vice versa then the universe probably teams with microbes with these two what these I Feldman's because they're probably everywhere they're probably ubiquitous in star systems and yeah that changes the equation too because if you're you know everybody's worried about certain stars being not never suitable for life because our habitable zones are too close in like the red dwarfs well what about a nice shelled moon around you know planet rotating around a red dwarf could life still show up there because it's shielded by the ice you know so it's a it's I would find that to be a really alluring concept that yeah the universe is alive it's just microbial and that we're rare but microbes are yeah and I think for me what this would do if we could even prove that one of the moons of the solar system was inhabited is that we could finally stop calling the apples or the Hat also because it to me I don't think that's a good description what you're asking when you say the Hat boson is if you take an earth like an exact copy of the air right down to its movement and it's magnetic field and its atmospheric pitch which is quite specific and it's only really arrived presently the atmospheric mix of the arocs compared to what it was billions of years ago is very different and that's a non-factor and climate changes that even a few hundred million years ago that miss Ferrett mix was different you take this planet which looks exactly like ours today and you move it around a different radii different orbital radii and you get different temperatures and this is how you build up your zone all that's telling you is where earths are set are suitable for life them that lives on the surface doesn't tell you anything about where you should put your icy moons so the apples own if you like the true haps balls where any form of life can live on anybody could be much much bigger and we should therefore call this thing we called the apples on the the liquid water zone or the warm terrestrial zone or something like that which is more descriptive and acknowledges the fact that maybe life is much richer and more interesting and amazing even though is on the Eric which is already pretty rich interesting and amazing to begin with well Earth's first life is resilient and if the rest of life in the universe is resilient it could surprise us which then you get into really speculative stuff like dice and sunflowers and things like that but you know who knows now this isn't the only way that we can solve that question or get close to solving that question there's also the biochemists doing the follow ups and successive experiments to the miller-urey experiment where they're trying to see how hard it is to get life started chemically and if they ever nail that we can say well that's really hard and probably doesn't happen very often or we can say man this probably happens a lot but then you have to get through the filters the great filters what do you think is the single most the biggest showstopper for life as you go through the filters they're all pretty big aren't they I mean just getting yourself set up to be self-replicating in the first place is hard having proper inheritance of genetic information is hard there are a lot of things that about us that seem to have happened by accident that our cell structure seems to be no the consequence of two organisms colliding and one being eaten by the other and then realizing hey this is actually a good setup let's do this is that always destined to happen probably not I mean I think to be honest if if you're taking what we see currently as evidence there's nobody else like us then what that means is that the great filter is somewhere in our past okay we somehow managed to survive that particular obstacle and if that's the case then I would put it much further back than humans I think it Polly goes back to the development of brains themselves the idea of having a nervous system like like ours that's sufficiently complex in advanced that at a certain point you know you have this thing that happens that I think it's 70 thousand years ago or something retake our ancestors we have anatomically quite similar brains to us but we're not capable of doing the things that we're doing and then suddenly everything changes you know you know the first indications that we have a real society we our language we have inheritance rapid evolution of of tools and technology and culture so yeah I would say it's probably to do with the formation of brains because you can be quite a successful organism without having a brain you can have your your nervous system being quite distributed to the point that you don't need a central nervous organ like behalf yeah I would play put it there nothing that's where I would end up now that leads to possibility that intelligence could be so rare and for all intents and purposes at least within the local group of galaxies unique that would make earth very very special and that we actually are the lottery winners of the universe so to speak or at least are part of this the observable universe so do you think that that's more likely than life being somewhat ubiquitous do you think it's more likely that we're just living on a very very special world well I think it's immediately clear whatever you think about intelligent life or life in the universe we are living on a very special world I think that's one of the great things about astronomy is it gives you that perspective allows you to look back and see the earth is amazing and I think your your scenario of us being alone in the local group it could be possible I mean it might well be the case that we're not actually alone but in terms of the distances that it would take us to traverse to get to the next civilization or for a radius enough to get there were effectively alone we can never communicate that might be true and if it is true and we are the lottery winners in our part of the universe how are we spending our winnings and I think that's the thing that depresses me so this this work can have lifts me up and also brings me down it lifts me up because it makes me think of you know just how amazing this planet is and how lucky we are to be here but it does bring me down when they think Coreper doing with that incredible fortune I think I tend to lean towards the idea that maybe we're not entirely alone but it just is the case that we we passed like ships in the night never knowing that we exist and that maybe it is the case that there's not many of us intelligent life is rare but not too rare but it's it's short so I tend to take a little bit of Colin little better call and be that maybe there's hundreds or thousands of intelligent civilizations out there but they tend to live and die without ever really learning of each other's existence just because their existence is so short and the galaxy is such a big place you know it's it just goes to show that we really need to pay attention to preserving the planet and preserving our own civilization and intelligence because it's precious its it if it's so rare and it's precious then it becomes an imperative for us to survive I think that's one reason to do the search and then not find anything you know some people come to me and say if you don't believe you're gonna find anything why bother and I think well if you can confirm to a fairly high level of certainty but there are no radio signals no artificial structures no signs of any technology in a thousand light years of the earth what does that mean for us how should we look at ourselves as a species if we can take that result and we can kind of feed it into the human psyche and say look at how special you are and look what you're doing to yourself maybe that might help us tonight by Oh some of our worst impulses and might help safeguard the future of our families in our future of our planet basically that's interesting so in such a case then a null result from SETI is still a net positive for the human species yeah and it just shows us that we're rare yeah it doesn't matter if we don't find anything the important thing is that we looked and we saw what it was to be human absolutely and on that note we are out of time thanks for joining us today doctor thank you for having me well that was a good show let's see what I missed you have one new message what why is Schrodinger's possum taunting me on my answering machine I don't know John but he sounds angry I just want my LeBaron back it has gone on to better things John I guess I'll have to start looking for something new to get me around I do need my Maker dammit John reminds me to analyze your diet wait stop it I like the spray bottle better that's a good idea water and electricity don't mix on the contrary they mix rather well

Channel: Event Horizon

Views: 141,510

Rating: 4.796113 out of 5

Keywords: fermi paradox, What is fermi's paradox?, Can We Solve Fermi's Paradox?, Dr. Duncan Forgan, Duncan Forgan, event horizon john michael godier, event horizon, godier, ASMR, Do alien's exist?, aliens, Solving Fermi's Paradox, alien civilization's in our galaxy, alien civilization's, ancient alien civilizations, where are the alien's?, Exo planet, Von neuman probes, science, nasa, space, dyson sphere

Id: aEmCYv8QII0

Length: 66min 28sec (3988 seconds)

Published: Thu Jul 18 2019