Alien Civilizations and the Search for Extraterrestrial Life. The podcast ''Alien Civilizations and the Search for Extraterrestrial Life'' - where computer scientist and podcaster Lex Fridman interviews physicist and astronomer Adam Frank - is amazing! Listen here: https://www.youtube.com/watch?v=yhZAXXI83-4&t A short recap: First Frank notices that there has been 10 billion trillion experiments to form civilisations in the Universe. A rough estimate. Give and take few. Still: 10^9 * 10^18. Thats a huge number... The only way we can be the only civilisation that ever existed in the Universe, is if all the other experiments failed... And if that isn't mindblowing enough... Then well, we are just getting started in this podcast... I.e. the probability of getting a civilisation out of a ''habitable life zone'' in a star system has to be less than 1/ (10 billion trillion) (for us to be the only civilisation in the Universe). In Franks words: ''Unless Nature has something against intelligent civilisations, we are not the first civilisation''. Normally, in discussions about this, the usual counter-argument is that ''but there are hard steps which evolution have a difficult time crossing''... Not really, according to Frank. If you are an evolutionary biologist you recognize these steps: ''But somehow life finds a way'', like it does with all of the other steps... The next counter-argument that usually follows is the ''Fermi paradox'', ''but then, where is everyone...''? Well, There is no paradox... A civilisation can hop through the Galaxy in a couple of hundred of thousands of years... But who says that a civilisation lives that long. And who says that we are there to see it, when it occurs...? The astronomer Jason Wright explains it like this: Imagine that the sky is an ocean... Then someone says: ''There is no fish in the ocean''... Then you need to ask yourself: ''How much water have we looked into''. It turns out that we (SETI) has looked into a hot tub of water... That is not much... And based on that we can't conclude anything.. Indeed, if civilisations last only a couple of 100.000s of years. They might have been here. But we might now live in a ''bubble''. Where we are the only civilisation. Nothing lasts - so we wouldn't be able to find any IPhones they might have left behind... 100.000 years is a long time in our world. As a technical civilisation we have only been around for 100 years. And we are already ready to blow ourselves out of the equation... So, if we get a signal from another civilisation - they are likely much older than us. And we can then ask them: ''So, how can you avoid destroying yourself''? And what if they are around, but far away? Can we detect them? I.e. can we detect an alien technosphere? According to physicist Freeman Dyson: Any dream we have, unless it is contradicted by physics, will sooner or later be realized. For an alien civilizations (thousands of millions of years older than ours) all of the things we can only dream about will therefore already be a reality. So, the search for alien technosignatures is first and foremost about having a clear idea of what we can expect from our own future. We can find aliens if we imagine ourselves in the future: If there is another civilization somewhere in space, it is almost surely much older than ours and has already managed to realize everything that we only dream of. Therefore, in order to find it, we must first understand our own possible future. Then we know what to look for. Next, we need to improve our ability to detect alien civilisations. >>''Unless an alien civilization is considerably more advanced than ours, they would have difficulty detecting the current levels of mobile tower radio leakage from Earth. However, the team suggests that some technical civilizations may possess far more sensitive receiving systems, thereby significantly increasing our mobile system's detectability.''<< Detecting biospheres is also doable. See e.g the articles: ''Thermodynamics and the recognition of alien biospheres'' and ''Thermodynamics and the recognition of alien biospheres''. https://royalsocietypublishing.org/doi/10.1098/rspb.1975.0051 Still, what we want is an image.... Other techniques to use would be ''Solar Gravitational Lensing''. There you be able to see structures on exoplanets down to 24 kms. Or something like Manhattan. If they have such a thing... So, what does an alien look like? Assuming that life on the alien worlds are created with Darwinian evolution. Then that life form it is a solution to the problem of surviving... Then: You need to get to your energy source. You need legs. So that is something we would expect the aliens to have... The aliens need to stay alive and reproduce... Perhaps ? Then: Where is their cognition coming from ? Do they have brains? What kind of brains? Could they have ''liquid brains''? Where cognition is distributed in a system. In other words: Do they have Hive minds ? And then what happens when they get so advanced as to be able to follow ''ideas''? I.e. after an evolutionary phase, the aliens might then become a purpose driven civilisation... I.e. yes, sure, ''evolution has no purpose''. But if the aliens break into the ideas phase - then civilisations can have a purpose. And then they can have goals. And they can have a direction... Would they be interested in communicating with something like us? Well, according to Frank, they might have been interested in us 10 million years ago. But by now they might have seen young civilisations millions of times - and they might not be that interested anymore? Asked about the biggest scientific questions out there - Frank points in the direction of questions like ''What is life'', ''What is it to be''... ''What is agency''... ''How do you get from physical equations to >>being<<'' See Adam Frank et al. ''The blind spot: Why Science Cannot Ignore Human Experience''. Science is blind for the precondition for science, that there is ''presence''. Somebody is there to observe. If you ignore that and think that you can build a worldview without it - it leads to trouble. You can ''go a long way with reductionism, objective frames and physicalism - But, what they all do is that they all leave experience out''. And then then you hit a wall when you have to talk about agency. You can't do science without being present in the world. You can't substitute a formal system for actual experience, there is always actual experience. Science is ''just'' the experiences we can agree on. But we can't say that a temperature - 23 degrees - is more real than the experience it came from, ''hot or cold''. Experience is weird, and unexplained. Sure you can deny or ignore it, but it doesn't explain agency and experience. The third person viewpoint is a fiction. All stories comes out of being. You can't ''un-embed'' you from the world. Time appears with us. This is our experience. If we try to impose a 3rd person view of a block universe, this doesn't tell us about our experienced time. According to Frank: Agency and autonomy are 2 sides of the same thing. If you treat equations as more real then experience, you come to the conclusion that there is no agency. But then again you are missing experience, as it present itself to us: ''Don't confuse the map with the terrain''. If you say that agency is an illusion, then you have already taken the 3rd person stand, which is a construction. Indeed: The 3rd person view is following the (religious) impulse of having a ''real'' 3rd person view, out there, which is ''more real than the >>agent in the world<< view''. In the western (religious) tradition we have this tendency to point to an outside frame, whereas other civilisations (eastern) have had other viewpoints, more centered on your own agency. Where they wanted to know more about their own (first person) experience. Still, Nothing exist in itself. (Perhaps) Not even raw experience? We are embedded in the world. A great podcast, indeed! December 23rd. 2024 Simon Laub.