With the recent discovery of phosphine gas on Venus, we debate whether Dan Dare has now been vindicated.

This podcast explores what we can infer from the small amounts of data we receive from space, and whether we have sufficient data to develop meaningful models of what is happening on other planets. We also discuss the way theories and counter-theories develop and - of course - alien life itself and the probability of its existence in different forms.

A few things we mentioned in this podcast:

• ‘Phosphine Gas in the Cloud Decks of Venus’
• Bill Clinton’s announcement about the Allan Hills meteorite
• Why Nick Bostrom hopes we don’t find extraterrestrial life
• The Drake Equation
• The search for megastructures
• Life on Venus is bad news in terms of the Great Filter

For more information on Aleph Insights visit our website https://alephinsights.com or to get in touch about our podcast email [email protected]

Hello and welcome to the Cognitive Engineering podcast produced by me, Fraser McGruer for Aleph Insights. In this series of podcasts we take a look at interesting topics and discuss what we think they tell us about analysis and decision making. I'm here with Peter Coghill and Nick Hare of Aleph Insights and this week we're discussing life on Venus. Nick, I was going to say this week we're discussing whether there is life on Venus

but apparently there is life on Venus. Well not necessarily. So there has been a paper for a while there's been speculation, I mean dating back 30, 40 years, speculation about whether or not you could have life on Venus and superficially it's a very hostile environment. The temperature is hundreds of degrees at the surface. The Russians developed some Venus landers that landed there in the 80s and were very quickly destroyed by the environment, as expected, but I mean they were able to send back a lot of useful data. But within the clouds of Venus there is a habitable zone, a zone that we think probably could support what we understand to be the basics of life. At the same time there's been these mysterious dark patches appearing in the clouds of Venus which have been observed ever since we've been looking at it and no one's quite sure what they are but one of the theories was that it was essentially photosynthesis of some kind that you know some organisms were capturing light and so that you know there wasn't an algae bloom. Yeah it's the sort of thing. Anyway last month to much excitement Greaves and a whole bunch of other academics published a paper called Phosphine Gas in the Cloud Decks of Venus and they were looking at essentially the wavelengths of light that are reflected from Venus. So using spectroscopy, so analysing the light waves that are reflected from the surface of Venus, we can now be very accurate about working out precisely what the chemical composition is of those gases in the clouds and it turns out there's very high levels or unexpectedly high levels of a gas called phosphine ph3 which I don't know much about, I'm not a chemist, but as I understand it the only known process on earth which produces phosphine in anything like appreciable levels is bacteria. So it's bacteria specifically anaerobic bacteria who emit it. They're not quite sure why whether it's a waste product or whether it's just designed to sort of because it's very toxic to get rid of you know enemy bacteria or whatever and it's broken down quite quickly by sunlight, phosphine, so apparently something must be generating it. Now there are processes, there are chemical processes which can produce phosphine but as I understand it as far as the scientists understand they can only occur on gas giants right so the specific chemistry of gas giants. Venus isn't, it's a rocky planet. So the point is this is considered to be a bio signature. The production of phosphine is highly consistent with there being bacteria on Venus in the clouds of Venus. So first of all what does this mean? I mean how do we work out how likely it is that this is actually bacteria of some kind and secondly what would it mean if it was? What would it mean if there was life on Venus? Food for thought.

I was going to say why are we discussing this because you know we're not astrobiologists.

Well I'll tell you why. First of all you've just told us why. Well because I think the whole question of how you make an inference about data when you are not sure what the model is kind of thing and but I think more generally what does it tell us about life you know about whether life could exist elsewhere. What does it mean finding it on a doorstep? Okay talking about

strange forms of life. Peter. Well I haven't really got much to add to the intro. This might be a quick podcast. No I've got other things to talk about. Ah okay. But yes Nick's quite correct. There are biological processes prevalent all over the earth which are known to produce it but there are industrial processes which we wouldn't expect to be replicated kind of in the natural world but it's either produced as a as the end product or as a byproduct of other processes and as Nick says yes the energies and the chemistry available within the gas giants being Jupiter and Saturn of course can cause it to be formed out there or near the core and but we're talking like the composition is very different to a rocky planet obviously because it's not rock but the energies involved are massive. The pressures and the temperatures inside the core of these planets is vast compared to those found on rocky planets. So the speculation is just very unlikely to be caused by any known natural process on Venus. Okay. I've forgotten the

question why this is interesting. Well first of all I mean I think the first question is how does it work that we can think of a process on earth which is bacteria that generate phosphine now the fact that we can't think of another process that might be producing phosphine in Venus how likely is it that we just haven't thought of the thing that it actually is which is and so just I mean it's worth bearing in mind that you know in the 90s there was a lot of interest in the Allen Hills meteorite which was a meteorite that had originated from Mars and was found in Antarctica I think and there was a lot of excitement because they discovered on its surface deposits that looked like bacteria or you know not like earth bacteria but some possibly some kind of alien bacteria. Bill Clinton's you know issued a statement because it was so significant that we could have discovered life you know outside earth and anyway it's now known that this is just the simple you know result of chemical processes. So you know we're in a position where we don't really necessarily know that we might have just not thought of what the process is or there might be a process that we can't imagine for whatever reason you know which is producing this that we just haven't encountered on earth you know and but this is quite a common situation where you have data and no model and it's much harder like most analysis goes the other way like most analysis is like where you have a model and you have some data and what you're trying to do is fill in the rest of the data with the model you know so if you're trying to work out you know how likely it is that someone has a particular disease and you have a load of imaging data and you also understand that process where you know what the difference is between the kinds of images where they've got the disease and the kind where they haven't you know and you can put a certain probability on it and we all of the processes are understood right we totally understand how that disease behaves we understand how the imaging behaves and and there's no kind of uncertainty is all understood and quantified but here we're in a very similar situation to a lot of you know sort of astro astronomical problems which is that you know we see phenomena that we don't really know how to explain and and if you look at the history of astronomy it tends to you know new concepts appear as a result of finding weird inexplicable things like you know when they discovered quasars or phasars or whatever it was where you know they were getting these regular routine radio wave transmissions and everyone thought well that's it we've discovered an alien civilization it turned out it was just these you know extremely fast spinning stars likewise you know that's that's I mean how likely is it that that's that's the case and I think it's a bit like you know you you don't really know how big that space of possible processes is and how much of it we've searched so so yeah that's that's what I'd say is I I think it's pretty exciting but it's very hard to to say what the probability is that this is life all we can say was is that it might be okay and that most of the times in the past where we've thought that something might be life it turns out not to be but that in this case we've got some other equally good reasons for thinking it is

Peter I think it might help to sort of I mean I'm just trying to work out what's different about this one from all the other ones but why is possibly you know more indicative but anyway

sorry Peter so it might be helpful sort of uh provide a bit of sort of a kind of like as a casual observer of science um how much should you really take this seriously so on one hand there's lots of good science saying yes it's quite a high probability that it's uh as a result of biological life so non so yeah but there's a biological source to it that said um it's this this is the first paper that has um provided this as an explanation um now this will become because it's quite big news and it'll be a source of lots of funding for research groups etc this will become a big thing and as a result there'll be loads of counter theories presented and maybe slightly more obscure chemistry that people haven't necessarily really pinned down and saying actually this kind of process could occur in the natural world like venus a natural environment like venus under the following circumstances and then so there might be there'll be counterexample counter explanations for it so it's a good it's a good it pushes up your so how far should it push up your probability of believing there's life on venus i would say a little bit you know rather than a big leap okay right like the headlines would like to have you believe and i think the original authors would say yes it's just one possibility it's not like it's not definitive um so yeah so there's going to be lots more good science um as a result there's probably going to be big grants for sending probes to venus to collect more data and scrape the clouds and to image you know have orbiters and things perpetually sampling it's all good for human exploration um but it's not yeah

it's not there's certainly nothing definitive about this yet okay um yeah so i'm going back and forth saying peter nick nick peter peter i mean i don't really have aliens so is this what

we want to talk about is well i think i think i don't know if we've ever done one about uh alien life but now i suppose this is where i want to introduce a note of probably some quite existential caution because um nick bostrom who is uh a um who is a well he's actually a philosopher but he's done a lot of work into catastrophic risk and uh he's looked at you know artificial intelligence safety and that kind of thing but he wrote this quite famous paper called why i hope there isn't life on mars and um to understand where he's coming from first of all you know we've got to think about uh sort of various various um various other kind of concepts that people have considered over time one of the first people to really think about this seriously was when did he write this paper he wrote the paper about 10 years ago or something okay so frank drake who was a um who was a i think he was maybe one of the guys who worked on the manhattan project or anyway he was a scientist about 50 years ago um came up with a kind of model for for uh how many intelligent space-faring civilizations there should be out there and um you know he looked at things like well how many uh how many stars are there at any given time uh how many of them have planets um how many of those planets are going to be habitable kind of thing and then you know what's the chance that life starts on on a planet given that it's not there to begin with and then goes on to become intelligent life and then that it develops a space-faring technology and you know becomes a sort of alien uh an alien of interest and presumably to presumably the

chances are so so so tiny but actually you end up with loads of them because it's such a big universe

right exactly and they're all far away and we're just talking about the milky way we're not even thinking about other galaxies just this galaxy yeah so the and and they initially they they thought there's probably thousands of them out there and this takes into account the life the average lifetime you know you think well how long are they a space-faring civilization for um so on one hand you've got the drake equation which seems to say well there's loads of uh there should be loads of intelligent life out there yes it's a tiny probability it'll happen on any given planet but there's so many planets in fact as time's gone on we've discovered more and more exoplanets and you know we know that they there must be exoplanets that are in habitable zones and you know a lot of them have water and so there's actually like we've kind of we've also sort of

tweaked what we believe to be the habitable zone it's got wider if anything because of discoveries of extremophiles on earth yeah yeah yeah yeah they can survive in sort of non-traditional

habitable zone areas right exactly like venus in fact and uh venus is very acidic but actually there are there are bacteria that live in acidic pools in uh in on earth but then the response to the drake equation was from was enrico fermi the fermi paradox where he said well if that's true like where are they because as soon as you become a space-faring civilization you ought to pretty quickly and i mean over millions of years but that's quickly in a sort of you know geological time very quickly take over the whole galaxy right you should just spread capture more and more energy capture more mass spread throughout the galaxy so if that's true where are they and and so you know people who take that uh who take that seriously uh sort of essentially you've got two options one is that we're actually the first the other is that well the drake equation the numbers we put on are wrong and that's somewhere within the drake equation there's what's called the great filter

so the there is a third slightly less serious well the third is let's get david icon well i mean i

mean yeah i'll be interested i want to hear what peter's uh third option is it was this filter thing so so the well first of all to say that if life's common and the idea that we're the first just has to be very very unlikely if there are 10 000 alien civilizations that we would expect to see soon and we're the first well there's only a one in 10 000 chance that that's the case so that's kind of an unlikely theory to begin with the great filter is saying well actually we've got it wrong that life is incredibly rare for some reason but intelligent spacefaring life is incredibly rare and it could be a number of reasons right so so it could be for one end well maybe there aren't any exoplanets maybe earth is just incredibly rare maybe getting life going in the first place you know one prokaryote is just really hard to evolve but then maybe multicellular life well that was the big innovation that happened here but isn't going to happen anywhere else and um you know all the way through to well maybe for some reason technological or economic it just is impossible to become a spacefaring civilization like it just turns out to be the energy you need is too high and and in fact it's never never makes sense to do that um through to you know well actually all organisms that evolve evolve in a competitive environment and eventually destroy themselves with the technology that you need to explore the space so if the great filter we're into one of two but we don't know where the great filter is is it in front of us or behind us but we assume it exists because those aliens aren't there if the great filter is behind us great yes because it means that we're on track off we've gone through the great filter and it's space here we come yeah if the great filter is in front of us oh dear bad yeah we're gonna kill ourselves we're not gonna ever get to that dandere dream the whole point of this nick bostrom paper is to say if we find life on our doorstep right it shows that that's quite a lot of the great filter is is not is is cannot is is not in bits that are behind us and it pushes where it might be so that it becomes more probable the great filter is in front of us right so so if is it we might have comforted ourselves and said well you know but it's really difficult to get bacteria to evolve that or to get single-celled life to evolve like that's really really hard so we've got through that so that's great if it turns out that actually it's all over the place including in venus then we can't comfort ourselves with that and we face the the fact that actually the great filter is more likely to be in front of us it's a bit like if you're trying to work out why girls haven't phoned you you know and you might think well maybe there aren't any girls in my area um but or maybe they don't fancy me uh or you know maybe my phone's not working and then you discover that actually there's loads of girls in your area because you look on tinder and discover there's millions of them and it turns out that they well it makes it more likely that they just don't fancy you you know it's sort of that kind of situation we we've we've just we kind of discovered that we're in a situation where we might not where we we we might not be through the great filter and we've got all that horror to come

interesting interesting peter so there's a couple there was so i think robin hansen i think was the first guy to posit the uh great filter right idea could have been yeah um so so uh so the whole life being on the doorstep idea there might need to be a nuance you have to consider so it might it might just turn out that it's very easy once you once life evolves on one planet for it to then spread in a very primitive form to other planets within that system so the the the trip to venus or to mars from earth assuming it evolved the first on earth is pretty small uh and it and it's and as that as the the meet what was the name of the meteorite alan hills down the hills meteorite yeah um showed that rocks from one planet quite regularly land on another and there are there are there are there are there are theories uh called panspermia um it's a lovely word uh which which which explain the mechanisms for how how this can happen so usually involves some sort of cataclysmic event the big meteorite hits the planet and just throws lots of stuff up some of which is thrown up with enough energy for it to escape the orbit and land on neighboring planets now interstellar travel is a whole nother ball game right so our nearest star is 4.2 light years away um uh which is around 27 000 times the distance from us to our sun yeah so that's 27 000 times sort of more kind of than what's already a long way already a long way to get stuff out there so it might be that the the just the chance of so panspermia might not be able to occur between between planets and between planets so that's something you have to bear in mind when you're considering these numbers so it might just be that life on the doorstep doesn't really tell you very much if like we discover life in the nearest star that tells quite a bit more yeah

it might be that really we're discovering the same life we're discovering the same and i suppose you'd want to look at the bacteria and find out if they're do they share a common ancestor with

exactly yeah we we need to kind of i wish we didn't have to but we kind of need to wrap this up and by the way people who work on this stuff full time how do they get up in the morning have their cornflakes i don't know i mean just i mean how do they sort of live a normal life and go around it's so fascinating yeah and absolutely you know how could you um so i wanted to bring

up there was a third there was a third idea okay yeah go on so there's a like there's the i'm not sure how serious this is but it you know if you're a star trek fan it seems plausible um but the idea of the cosmic zoo cosmic zoo cosmic zoo okay so this is where there is the early early much earlier in the life of the universe uh intelligent life evolved yeah uh and became space faring and in terms in our in our terms in our technological terms they are godlike they are very powerful they can move without being seen they can travel around etc etc at great speed um and they've taken upon themselves to sort of curate the life of the universe yeah or the galaxy and only select those life forms which they deem worthy by some by some measure okay so they so when so when when planets evolve life that gets to a certain become space faring and begins to sort of encroach on their turf yeah if they like the look of them they'll let them into the club and show them how to how to operate as they do if they don't they'll just sort of expunge

it i think that's the day the earth stood still right klartu comes to earth and says you know you've got to the point where you're going to destroy yourself and so we we've come to say hello yeah and you know we're going to teach you to stop being such morons yeah no this is also

straight off star trek and this is it's like um basing theories of time travel on back to the future that's what it sounds like to me so far so i really like the idea or there's also the

everything's great i like this great filter concept um but also sum up another way either i forget where i read this or who said this either we are alone or we are not either way it's mind-boggling yeah yeah this being the case uh i've got a i've got a great question for you okay what or who is your favorite alien presumably we're taking this from the realms

of fiction right yeah maybe not i'm not allowed the venusians the venusian cloud bacteria you well you are actually you know you are allowed no i'm not going to pick them they're boring

their conversation is so yeah so yeah who or what or from where is yeah your favorite alien

have a think about that well i've got uh i do have an answer but i i don't want to it might

be the same as peter's it probably isn't go ahead go first go on my favorite you got a few okay god i've been trying to think of the last 10 minutes but anyway yeah go on um my my favorite

alien actually cartoon from um from the day the esther still is up there actually because he played by michael renny who i love but my favorite alien is just the good old-fashioned alien from ridley scott's film okay and what i liked what i like about it is it now the the issue is is a man in a suit now he was trying it's sort of trying to get away from that a bit by making it really mysterious and strange looking and i think he did a pretty good job and you can head cannon it a bit by saying well you know any animal that evolved anywhere is going to evolve legs because you know you're not going to evolve wheels and i thought it was accepted canon the alien was a manufactured right right so what i was going to say is how incredibly disappointing it is right in the same way it would be disappointing to discover that these venus bacteria um actually evolved on earth and just moved planet um how incredibly boring it is that the uh you know prequels prometheus and covenant decided to make it the case spoiler alert if you haven't seen them but decided to make it the case that they were created by an android um you know the aliens the aliens were just were bred specially you know to be kind of weapons essentially um by a an android that was created by a human and and of course you know in much the same way that it would be disappointing to discover that the venus bacteria if they exist evolved on earth it's super disappointing that you know you look at alien that that set with the space jockey it's just one of the best sci-fi scenes ever made because it's so mysterious it's so properly alien you just they have no idea what these things are or where they come from or where they were going and you didn't need to know any of that because you just thought well that whatever this is it's i know i i'm not going to understand it is someone that has done this for reasons that i couldn't comprehend but the net result is you've got a terrifying alien in your spaceship um now it's like oh right so some boring android made these and left them here well that's you know something shrinks the

universe right yeah yeah yeah yeah uh peter you and your many aliens so i'm a big fan of the borg

from star trek specifically the next generation and voyager and uh indeed uh deep space nine but yeah they so they are if you're not familiar they are a a cyber cybernetic race they're part biological part machine um and they operate in a totally connected um sort of uh like this is starting to sound like an advert yeah go on yes an advert for my utopia they're they're they're totally connected in this thing they call the unimatrix i think yeah basically they're all connected by the internet to each other and they can talk to each other etc etc and they they they behave more like a sort of swarm of ants or flies the coordinated swarm than they do

as a group of individuals you mean just like democrats sorry that's i'm that's a quote from a bob hope i'm not i don't i don't mean that i just couldn't resist um and the reason i like

them is that it would have been very easy to write that that that species as being kind of having a particular prejudice that they're trying to expose like they do with others so other star trek races are modeled on various despotic um nations and things but the borg they're only prejudices against imperfection and they have a very particular view of what perfection is imperfection is is they're pursuing always pursuing it never and acknowledging they'll never reach it but the way they go about doing that is a simulation of other races and they they when when you meet the borg it's bad news because you're probably going to lose the fight but they say prepare to be assimilated your uniqueness will be added to our own because they they don't they don't try to expunge people's uniqueness they're trying to bring it in yeah

in a way the perfect multicultural society in a way yeah in a way but but you do once you're a

borg you don't mind right once you're happy you don't know yeah and and and and many bore when when released from the collective suffer great sort of psychological damage because they want to go

back in it seems like these borgs are they're onto something in some way in many ways yeah yeah

they get a bad they get a bad they need better pr don't they they need better pr yeah um well they've just got some um okay i i don't really have an answer there's so many um you know i quite like q i quite like the q continuum yeah um in star trek just because he's a bit of an annoying he's got a bit of number two really oh okay so i'm in good company um you know he's just fun if you can call him a he i don't know but and i like the way he always winds up picard and makes picard look a bit dull and um pedestrian um what i like about the q is it's a sort of

logical end state for a all-powerful race of being that doesn't have any physical form can take can can manipulate energy and matter to do whatever they like to the point but they still have failures of their where they their previous race are a bit like a bit human in a way because they've become entirely decadent because they have the always power they've got nothing more to achieve they just go around causing a nuisance with other people yeah no quite a bit fun does that does

sound familiar yeah um i can see you've thought about this a lot more than i have already um okay we're going to wrap up there um thank you as always for listening to the cognitive engineering podcast i'm frase mcgruer i've been here with nick hare and peter coghill of aleph insights until next time goodbye