Speaker 1: Welcome to Bedtime Astronomy. Explore the wonders of the cosmos
Speaker 1: with our soothing Bedtime Astronomie podcast. Each episode offers a
Speaker 1: gentle journey through the stars, planets, and beyond, perfect for
Speaker 1: unwinding after a long day. Let's travel through the mysteries
Speaker 1: of the universe as you drift off into a peaceful
Speaker 1: slumber under the night sky.
Speaker 2: Are we alone in the universe? I mean, it's a
Speaker 2: huge question, isn't it something humans have probably asked forever
Speaker 2: looking up at the night sky.
Speaker 3: Absolutely, it taps into something really fundamental about our place
Speaker 3: in the cosmos.
Speaker 2: For so long it felt, you know, purely philosophical or
Speaker 2: maybe just science fiction fodder. But it seems like actual
Speaker 2: scientific research is starting to weigh in, maybe giving us
Speaker 2: a more well, a more precise answer.
Speaker 3: That's right. Recent studies are trying to model the probabilities
Speaker 3: based on what we know about planets, stars, and life itself.
Speaker 2: Sure that's emerging is maybe a bit surprising, Perhaps not
Speaker 2: the crowded galaxy we sometimes imagine.
Speaker 3: It certainly suggests the odds might be steeper than we thought,
Speaker 3: especially for technological civilizations like ours.
Speaker 2: Okay, so that's what we're exploring today. We're going to
Speaker 2: look at some really fascinating findings about well, the incredible
Speaker 2: odds stacked against finding other technological civilizations just in our
Speaker 2: own galaxy, the Milky Way.
Speaker 3: Yeah, looking at the specific conditions needed, the planetary set up,
Speaker 3: the atmosphere, and the.
Speaker 2: Time scales, almost unimaginable amounts of time involved for life
Speaker 2: not just to appear, but to get to a technological stage.
Speaker 3: Exactly. It's a multi layered challenge.
Speaker 2: So get ready because our discussion today might just shift
Speaker 2: how you think about those little lights in the sky.
Speaker 2: We'll touch on how rare, how incredibly far away, and
Speaker 2: maybe how astonishingly old any cosmic neighbors might actually be.
Speaker 3: It puts things in perspective.
Speaker 2: Okay, let's unpack this. Then. We've all seen the movies, right,
Speaker 2: Star Trek, Star Wars, alien civilizations just jump away. But
Speaker 2: when we talk about actually finding another civilization, what kind
Speaker 2: of distances, what kind of time scales are we really
Speaker 2: up against? According to this new.
Speaker 3: Research, well, the scale is the first major hurdle. The
Speaker 3: reality based on these models is far more daunting than
Speaker 3: fiction suggests. Right, And it's not just the distance, although
Speaker 3: that's enormous. What's really fascinating or maybe sobering, is how
Speaker 3: the sheer scale of space and time compound the challenge
Speaker 3: as well. It's not enough to just find life or
Speaker 3: even evidence that life existed somewhere else, sometime else. For
Speaker 3: us to detect another technological civilization, they need to be
Speaker 3: existing concurrently with us right now.
Speaker 2: Ah Okay, So they can't be long gone, and they
Speaker 2: can't be millions of years in the future. They have
Speaker 2: to overlap with our tiny window of technological.
Speaker 3: Existence precisely, and that is a huge constraint. So when
Speaker 3: we delve into the numbers from recent studies, well they
Speaker 3: give us some estimates.
Speaker 2: Let's hear them.
Speaker 3: Okay. So the estimate for the closest technol logical species
Speaker 3: to us in the entire Milky Way galaxy could be
Speaker 3: as far as thirty three thousand light years away.
Speaker 2: Thirty three thousand light years.
Speaker 3: Thirty three thousand light years.
Speaker 2: Wow, Okay. Put that in perspective for us, how far
Speaker 2: is that really?
Speaker 3: Well, think about this. Our own solar system is roughly
Speaker 3: twenty seven thousand light years from the center of the
Speaker 3: Milky Way. Okay, So thirty three thousand light years means well,
Speaker 3: it means our nearest technological neighbors could easily be on
Speaker 3: the other side of the galaxy from us.
Speaker 2: The other side, so not just a different neighborhood, but
Speaker 2: a whole different continent cosmically.
Speaker 3: Speaking, exactly. Imagine trying to shout across a continent and
Speaker 3: hoping someone hears you. Now, not ten thousand years ago.
Speaker 3: Light itself takes thirty three thousand years to make that journey, So.
Speaker 2: Any signal we send takes that long to get there,
Speaker 2: and any signal they send takes that long get here.
Speaker 2: Communication isn't exactly.
Speaker 3: Real time, not even close. It's profoundly ancient by the
Speaker 3: time it arrives. It really paints a picture of potentially
Speaker 3: extreme isolation even within our own galaxy.
Speaker 2: Okay, thirty three thousand light years that distance alone is
Speaker 2: mind boggling. But then you mentioned this concurrency thing. They
Speaker 2: have to be there, now, how does that layer on top?
Speaker 3: Ah, That's where it gets even trickier, because for a
Speaker 3: civilization to exist at the same time as us, even
Speaker 3: across that vast distance, it needs to be incredibly long lived.
Speaker 2: Right, because they had to start existing long enough ago
Speaker 2: for their light or signals to reach us now, and
Speaker 2: they have to still be existing exactly.
Speaker 3: And this research, using planetary models and astrophysical data, tries
Speaker 3: to estimate how long lived they'd need to be. The
Speaker 3: minimum suggested survival time is two hundred and eighty thousand years.
Speaker 2: Two hundred and eighty thousand years minimum minimum, and potentially
Speaker 2: millions of years millions. Yeah, for a technological civilization to survive.
Speaker 3: Yes, think about what that implies. A species evolves intelligence,
Speaker 3: develops technology, and then manages to sustain itself at society,
Speaker 3: it's technology for hundreds of thousands, maybe millions of years.
Speaker 2: To us, Yeah, I mean how long we've been technological?
Speaker 2: A few centuries since the Industrial Revolution, maybe a few
Speaker 2: millennia with writing in.
Speaker 3: Cities, it's a blink of an eye. In comparison, to
Speaker 3: imagine a civilization lasting for say two hundred and eighty
Speaker 3: thousand years or ten million years requires contemplating a level
Speaker 3: of stability, resilience, resource management, problem solving on a scale
Speaker 3: we can barely conceive of.
Speaker 2: It suggests they would have had to overcome challenges we
Speaker 2: haven't even faced yet or are maybe facing right now.
Speaker 3: Precisely, it's not just about finding life. It's about finding
Speaker 3: a civilization that has somehow mastered long term survival against
Speaker 3: cosmic and potentially self inflicted threats. Well, it's a profound constraint.
Speaker 2: So it really hammers home that this isn't just a
Speaker 2: spatial search looking for a needle in a cosmic haystack.
Speaker 2: It's also a temporal one, a needle that might have
Speaker 2: existed ages ago, or might exist ages from now, or
Speaker 2: as maybe on the completely other side of the haystack
Speaker 2: right now, but has to have been there for an
Speaker 2: incredibly long time.
Speaker 3: That's a good way to put it. Concurrent exists is
Speaker 3: the key, and it demands exceptional longevity.
Speaker 2: Okay, so let's zoom in a bit. Forget the vast
Speaker 2: distances in times for a moment. What about the place itself?
Speaker 2: The planet? What makes a planet even capable of hosting
Speaker 2: such a long lived civilization. It can't just be any
Speaker 2: random planet, surely, what's the recipe?
Speaker 3: No, absolutely not, and you've hit on the next crucial layer.
Speaker 3: It's far more than just say, having liquid water, although
Speaker 3: that's generally considered essential, right.
Speaker 2: The fall of the water approach.
Speaker 3: Yeah, but this research we're exploring today really emphasizes the
Speaker 3: strong odds against finding truly earth like worlds capable of
Speaker 3: supporting complex technological life over billions of years. It boils
Speaker 3: down to a few critical, interconnected factors.
Speaker 2: Like a cosmic recipe, where everything has to be just right.
Speaker 3: Exactly, perfect measurements, perfect temperatures, perfect chemistry, all sustained for
Speaker 3: geological ages. Let's look at some of those key ingredients,
Speaker 3: starting with something quite fundamental to Earth.
Speaker 2: Okay, plate tectonics, plate techtics like earthquakes in volcanoes. How
Speaker 2: does that relate to alien life.
Speaker 3: Well, we tend to see the surface effects the dramatic stuff.
Speaker 3: But plate tectonics, the slow movement of continental plates, is
Speaker 3: actually vital for regulating Earth's long term climate. It acts
Speaker 3: like a planetary thermostat the thermosat. How it's mainly through
Speaker 3: its role in the carbon silicate cycle. Basically CO two
Speaker 3: in the atmosphere dissolves in rain water, making it slightly acidic.
Speaker 3: This rain whethers silicate rocks on land, washing dissolved carbon
Speaker 3: and minerals into the oceans. Okay, in the oceans, tiny
Speaker 3: organisms use some of that dissolves stuff to build shells,
Speaker 3: mostly calcium carbonate. When they die, their shells sinc forming
Speaker 3: sediment locking away carbon on the ocean floor.
Speaker 2: So it pulls CO two out of the air over time.
Speaker 3: Yes, But then plate tectonics comes in through subduction where
Speaker 3: one plate slides under another. These carbon rich sediments get
Speaker 3: dragged down into the earth mantle over millions of years.
Speaker 3: The heat and pressure release. It's the CO two which
Speaker 3: eventually comes back out into the atmosphere through volcanic eruptions.
Speaker 2: Ah. So it recycles the carbon, It pulls it out
Speaker 2: when there's too much, releases it when there's too little.
Speaker 3: Exactly, it's this incredibly slow but effective feedback loop. It
Speaker 3: prevents Earth from getting stuck in a runaway greenhouse like Venus,
Speaker 3: or freezing over completely like Mars might have done. It
Speaker 3: keeps a climate relatively stable over hundreds of millions of years,
Speaker 3: which is crucial for complex life to evolve.
Speaker 2: Wow. So plate tectonics isn't just about geology, it's about
Speaker 2: long term habitability. But you mentioned even with this system
Speaker 2: there's a potential problem a ticking clock.
Speaker 3: Yeah, that's the intriguing part. It's a great system, but
Speaker 3: it might not be perfectly balanced forever over very long
Speaker 3: time scales. There seems to be a natural tendency for
Speaker 3: more CO two to get locked away in rocks, then
Speaker 3: gets recycled back out through volcanism.
Speaker 2: Like a slow leak in the system.
Speaker 3: Kind of Yeah, a slow geological sequestration of CO two,
Speaker 3: And this leads to an inherent ticking clock on planetary habitability,
Speaker 3: at least for life like ours. Oh so well on Earth.
Speaker 3: The projection suggests that because of this slow depletion, atmospheric
Speaker 3: CO two levels will eventually drop too low for photosynthesis
Speaker 3: as we know it to continue efficiently.
Speaker 2: Photosynthesis will stop the basis of most of our food
Speaker 2: chain eventually.
Speaker 3: Yes, the estimates vary, but it could be somewhere between
Speaker 3: say two hundred million and maybe up to a billion
Speaker 3: years from now. Doctor Scherf, one of the researchers we're
Speaker 3: drawing on, puts it bluntly. At some point enough carbon
Speaker 3: dioxide will be drawn from the atmosphere so that photosynthesis
Speaker 3: will stop working.
Speaker 2: Wow, So the planet's own life support system had that
Speaker 2: kind of built in expiry date for complex life.
Speaker 3: For oxygen producing photosynthesis. It seems so, And this has
Speaker 3: huge implications for finding et well. If a planet doesn't
Speaker 3: have clate tectonics to regulate CO two in the first place,
Speaker 3: it might become uninhabitable much faster, or even if it does,
Speaker 3: like Earth, maybe this CO two depletion clock runs faster
Speaker 3: under different conditions. It means the window of time during
Speaker 3: which a planet can support comple flex life, let alone
Speaker 3: technological life needing billions of years to evolve, might be
Speaker 3: much narrower than we thought.
Speaker 2: So you need the geology, the thermostat. Yeah, but even
Speaker 2: then the fuel for life, the CO two slowly runs out.
Speaker 2: That really emphasizes the fragility. Okay, So the geology sets
Speaker 2: the stage, regulates the climate. But what about the air itself,
Speaker 2: the atmospheric mix.
Speaker 3: Right, because even with the right temperature regulation, the specific
Speaker 3: composition of the atmosphere is absolutely critical, not just for
Speaker 3: life to exist, but for its complexity and its potential
Speaker 3: for technology.
Speaker 2: Okay, Earth's atmosphere is mostly nitrogen, then oxygen, tiny bit
Speaker 2: of CO two.
Speaker 3: Yep, about seventy eight percent nitrogen twenty one percent oxygen,
Speaker 3: and that crucial tiny fraction of CO two around point
Speaker 3: zero four two percent, which keeps us warm via the
Speaker 3: greenhouse effect.
Speaker 2: But that CO two level is delicate, right.
Speaker 3: Extremely delicate. Too much CO two and a planet overheats
Speaker 3: think venus a runaway greenhouse effect, ocean's boiled away surface
Speaker 3: hot enough to melt lead. Or maybe the atmosphere just
Speaker 3: becomes too dense and toxic for familiar life into little
Speaker 3: too little, and the planet freezes. It can't retain enough
Speaker 3: heat from its star, so you need that sweet spot.
Speaker 2: So the research looked at different CO two levels.
Speaker 3: It did, and interestingly, it explored a scenario where a
Speaker 3: planet might have more CO two than Earth but could
Speaker 3: still be habitable for longer.
Speaker 2: How would that work? Wouldn't it overheat?
Speaker 3: Not necessarily if other factors compensate. The model suggest a
Speaker 3: planet with say ten percent carbon dioxide much higher than Earth's,
Speaker 3: could potentially maintain its biosphere its capacity for life for
Speaker 3: a staggering four point two billion years.
Speaker 2: Longer than Earth's projected habitable lifestam.
Speaker 3: Potentially, yes, but there's a catch, always a catch, right
Speaker 3: to avoid a runaway greenhouse with that much CO two,
Speaker 3: the planet would need to be significantly farther away from
Speaker 3: its star than Earth is from the Sun, or its
Speaker 3: star would need to be dimmer younger. Perhaps the extra
Speaker 3: CO two provides a thicker blanket, so you need less
Speaker 3: heat from the star.
Speaker 2: Okay, so location, location, location matters MATT precisely to the
Speaker 2: atmospheric CO two exactly.
Speaker 3: In contrast that ten percent CO two scenario with one
Speaker 3: having just one percent CO two, that planet's biosphere might
Speaker 3: only last a maximum of three point one billion years
Speaker 3: before CO two depletion becomes critical. So the initial amount
Speaker 3: of CO two interacting with the planet's geology and its
Speaker 3: distance from the star sets a fundamental limit on how
Speaker 3: long complex life might have to evolve.
Speaker 2: It's such a fine tune system geology, atmosphere, orbit. Yeah,
Speaker 2: I'll have to align perfectly. Okay, Well you mentioned oxygen two.
Speaker 2: Obviously we needed to breathe. How does that factor into
Speaker 2: the technology side? Ah?
Speaker 3: Yes, Oxygen is fascinating because it's not just about respiration
Speaker 3: for complex animals, which definitely need higher oxygen levels than microbes.
Speaker 3: It's about something even more fundamental for technology. Fire. Fire
Speaker 3: studies show that if the oxygen concentration in an atmosphere
Speaker 3: drops blow about eighteen percent, you can't have open air combustion.
Speaker 2: We really like a match wouldn't.
Speaker 3: Light exactly, A match wouldn't light, Wood wouldn't burn reliably
Speaker 3: in the open air. You couldn't sustain a camp fire,
Speaker 3: let alone the intense heat needed for things like smelting
Speaker 3: metal in.
Speaker 2: A furnace, and without fire.
Speaker 3: Without fire, the path to technology as we know it
Speaker 3: hits a dead end very early on. Think about it.
Speaker 3: The Bronze Age, the Iron age. They fundamentally depended on
Speaker 3: harnessing fire to extract metals from ore and forge them
Speaker 3: into tools, weapons, structures, metalworking, no metalworking, no steam engines,
Speaker 3: later on, no complex machinery, probably no advanced chemistry. It's
Speaker 3: hard to even imagine building a radio telescope or a
Speaker 3: spacecraft without the foundational technology that fire enabled.
Speaker 2: So you need enough oxygen not just to breathe, but
Speaker 2: specifically above that eighteen percent threshold to even get basic
Speaker 2: metallurgy off the ground, which seems like a prerequisite for
Speaker 2: any advanced attack.
Speaker 3: Precisely, it's another critical bottleneck. The atmosphere needs enough oxygen
Speaker 3: for complex life and enough for the key tool that
Speaker 3: unlocks advanced material science.
Speaker 2: Fire. So let me see you've got this straight. We
Speaker 2: need a planet with plate tectonics for long term climate stability.
Speaker 2: We need a very specific CO two level balanced with
Speaker 2: its distance from the star to keep temperatures right and
Speaker 2: sustain photosynthesis for potentially billions of years, and we need
Speaker 2: oxygen levels high enough, probably over eighteen percent, not just
Speaker 2: for complex animals, but crucially for fire enabling metallurgy and technology.
Speaker 3: That sums it up pretty well. It's an incredibly specific
Speaker 3: and likely quite fragile set of circumstances.
Speaker 2: It really makes Earth feel well, exceptionally fortunate, almost impossibly so. Okay, so,
Speaker 2: even if a planet somehow wins this incredible cosmic lottery
Speaker 2: and has all these conditions aligned, what's the next big
Speaker 2: hurdle for a technological civilization to actually be detectable bias?
Speaker 3: Well, winning the planetary lottery is just stage one. Stage
Speaker 3: two is time, specifically the enormous amount of time it
Speaker 3: takes for technological life to evolve in the first place,
Speaker 3: and then crucially, the time it manages to persist. Persist
Speaker 3: you mean survive, survive, Yes, survive itself, survive cosmic accidents,
Speaker 3: survive for long enough to own relap with us.
Speaker 2: Okay, how long did it take here on Earth?
Speaker 3: Well, our planet is about four point five billion years old,
Speaker 3: and technological life really only emerged in the last tiny
Speaker 3: fraction of that time, so it took roughly four point
Speaker 3: five billion years of evolution through countless steps in stages.
Speaker 2: That's a huge amount of time.
Speaker 3: It is. Think of the milestones the origin of life
Speaker 3: itself from non life that's a biogenesis, than the evolution
Speaker 3: of photosynthesis, which changed the whole atmosphere. Then the leap
Speaker 3: to multicellular life from single cells, then complex animals, nervous systems,
Speaker 3: intelligence tool use. Each step took hundreds of millions, sometimes
Speaker 3: billions of years, and there's.
Speaker 2: No guarantee that sequence happens everywhere, or it takes the
Speaker 2: same amount of time absolutely not, which brings us to longevity.
Speaker 2: The longer technological species manages to survive after it develops technology,
Speaker 2: the greater the chance it exists at the same time
Speaker 2: as another civilization like us. This is where that idea
Speaker 2: of the great filter often comes up, the idea that
Speaker 2: there are these huge hurdle's life to overcome.
Speaker 3: Exactly maybe the filter is behind us, like the origin
Speaker 3: of life or complex cells, meaning life itself is rare,
Speaker 3: or maybe the filter is ahead of us, meaning that
Speaker 3: becoming technological is relatively easy, but surviving with technology for
Speaker 3: a long time is extremely hard.
Speaker 2: And this research suggests the survival part is key very key.
Speaker 3: The calculations done by Shurf and Lammer really drive this home.
Speaker 3: Remember that planet with ten percent CO two potentially habitable
Speaker 3: for four point two billion years.
Speaker 2: Yeah, the one farther from its star.
Speaker 3: Right Even on such a potentially long lasting habitable world,
Speaker 3: for there to be just one other technological civilization in
Speaker 3: the Milky Way at the same time as us, that
Speaker 3: civilization would need to have survived on average for at
Speaker 3: least two hundred and eighty thousand years just for.
Speaker 2: One other civilization to exist concurrently.
Speaker 3: Yes, minimum average life span two hundred eighty thousand years.
Speaker 3: Think about that, maintaining stability, avoiding self destruction, managing resources,
Speaker 3: weather in cosmic storms for over a quarter of a
Speaker 3: million year.
Speaker 2: That puts our few centuries of industrial society into perspective chromatically.
Speaker 3: So, and it gets even more stark if you hope
Speaker 3: for more neighbors. How So, for there to be say,
Speaker 3: ten technological civilizations existing concurrently in the galaxy right now,
Speaker 3: the calculation suggests the average lifetime of each one needs
Speaker 3: to be over ten million years ten million years average average.
Speaker 3: As doctor Scherf noted, the number of potential alien civilizations
Speaker 3: depends strongly upon the lifetime of a civilization. It's not
Speaker 3: just about evolving, it's about enduring, surviving asteroid impacts, climate shifts,
Speaker 3: maybe internal conflicts, resource depletion, pandemics, you name it.
Speaker 2: Ten million years. I can barely imagine what human society
Speaker 2: might look like in ten thousand years, let alone ten million.
Speaker 3: That get well, it suggests any civilization we do find
Speaker 3: is almost certain to be vastly older than us.
Speaker 2: That's a very strong implication of these numbers. Yes, yeah,
Speaker 2: they wouldn't likely be newcomers to the technological stage. They'd
Speaker 2: be the survivors, the ones who figured out how to
Speaker 2: last for time, skills that are frankly geological. That's a
Speaker 2: truly staggering thought. Not just aliens, but ancient aliens who've
Speaker 2: mastered longevity. It highlights this potential fragility. Maybe the immense
Speaker 2: challenge of surviving your own technological advancement. Maybe that's the
Speaker 2: great filter.
Speaker 3: It's certainly a possibility that many researchers consider the challenge
Speaker 3: might not be intelligence, but wisdom and sustainability.
Speaker 2: Okay, these numbers, these conditions, they paint a compelling picture.
Speaker 2: Thirty three thousand light years away, needing to survive for
Speaker 2: maybe millions of years on a planet with incredibly specific
Speaker 2: geology and atmosphere. It makes technological life seem remarkably improbable,
Speaker 2: but science is always learning, right. How solid are these
Speaker 2: figures are their big unknowns, That's a.
Speaker 3: Really important point, and the researchers themselves are very clear
Speaker 3: about this. These numbers thirty three thousand light years, two
Speaker 3: hundred and eighty thousand years minimum survival, the atmospheric thresholds
Speaker 3: based on our current best understanding of astrophysics, minitary science, geology, biology.
Speaker 3: There are robust estimates based on today's knowledge.
Speaker 2: But not absolute certainties.
Speaker 3: Definitely not absolutes. There are inherent uncertainties in the models,
Speaker 3: and new discoveries, especially about exoplanets and Earth's own deep history,
Speaker 3: are constantly refining our understanding. Think of these as the
Speaker 3: best most informed calculations we can make now.
Speaker 2: And are there factors that just aren't in the calculation yet,
Speaker 2: things we don't know enough about precisely?
Speaker 3: The research explicitly acknowledges several huge factors that ideally should
Speaker 3: be included, but we simply can't quantify them reliably at
Speaker 3: the moment. They remain major unknowns. Genuine cosmic mysteries like what. Well,
Speaker 3: probably the biggest one is the origin of life itself
Speaker 3: a biogenesis. How does non living matter become living? How
Speaker 3: often does that happen? Even if conditions are perfect? We
Speaker 3: only have Earth as an example. Was it a near
Speaker 3: inevitable chemical process here or an incredibly lucky fluke? We
Speaker 3: just don't know the probability, right.
Speaker 2: If starting life is super rare, then even perfect planets
Speaker 2: might stay empty exactly.
Speaker 3: Then there's the origin of photosynthesis, specifically oxygen producing photosynthesis.
Speaker 3: It terrorformed our planet, paving the way for complex life.
Speaker 3: How likely is that specific biochemical pathway to evolve? Are
Speaker 3: there other ways complex ecosystems can be powered? Another big unknown?
Speaker 2: Okay, what else?
Speaker 3: The origin of multicellular life? Earth had only single celled
Speaker 3: life for what maybe three billion years?
Speaker 2: The leap to.
Speaker 3: Complex, coordinated multicellular organisms like plants and animals was a
Speaker 3: huge step. Maybe another major bottleneck. How often does that happen?
Speaker 2: Hmmm? The true life existed for ages before it got big.
Speaker 3: And then even if you get complex intelligent life, there's
Speaker 3: the frequency with which intelligence develops. Technology of the kind
Speaker 3: we could detect, think radio waves, large structures, atmospheric modification.
Speaker 3: Is that an inevitable path for intelligence or just one possibility.
Speaker 3: Maybe other intelligent species focus inward or develop in ways
Speaker 3: we wouldn't recognize technology.
Speaker 2: So maybe intelligence doesn't always lead to radio telescopes.
Speaker 3: Maybe not. So you have these massive unknowns at biogenesis, photosynthesis, multicellularity,
Speaker 3: the intelligence to technology leap, and how you view the
Speaker 3: probability of each of those steps really shapes your outlook.
Speaker 2: How so, Well, if you're an.
Speaker 3: Optimist, you might think each of those steps is actually
Speaker 3: fairly probable given the right conditions. If life starts easily,
Speaker 3: if photosynthesis is a common evolutionary solution, if multicellularity isn't
Speaker 3: that hard, and if intelligence naturally leads to technology, then
Speaker 3: maybe technological civilizations aren't quite as rare as the current
Speaker 3: planetary and longevity models alone suggest.
Speaker 2: Okay, that's the optimistic take.
Speaker 3: Right, But if you're a pessimist, or perhaps just more cautious,
Speaker 3: you might think each one of those steps is incredibly difficult,
Speaker 3: a major hurdle with a very low probability. If any
Speaker 3: of them are near impossible, then the already loan numbers
Speaker 3: we've discussed could plummet even further. We could be effectively
Speaker 3: unique or one of a vanishing a small number.
Speaker 2: It's like a chain, and if any link has a
Speaker 2: very low chance of forming, the whole chain becomes improbable.
Speaker 3: That's a good analogy. We're looking at this incredibly complex
Speaker 3: equation and some of the key variables, well, there's still
Speaker 3: question marks. It gives us a framework, a powerful one,
Speaker 3: but highlights how much we still have to discover.
Speaker 2: Yeah, it really underscores that science is a process. We
Speaker 2: have these amazing tools, these models, but the universe still
Speaker 2: holds on to some of its biggest secrets. Okay, So
Speaker 2: wrapping this up our discussion today, looking at this scientific
Speaker 2: analysis paints a really thought provoking picture, doesn't it.
Speaker 3: It really does.
Speaker 2: Technological alien life likely very rare, very far away, possibly
Speaker 2: incredibly ancient, all because of this precise, maybe fragile combination
Speaker 2: of planetary conditions, atmospheric balances, and the sheer difficulty of
Speaker 2: surviving for immense stretches of evolutionary and civilizational time.
Speaker 3: That seems to be the direction the evidence is pointing. Yes,
Speaker 3: a more constrained, perhaps quieter universe than we might have
Speaker 3: hoped for.
Speaker 2: It could feel a bit lonely that.
Speaker 3: Perspective and yet despite these odds, despite the potentially low numbers,
Speaker 3: the researchers driving this, like doctor Shirf, are adamant about
Speaker 3: one thing that the search must go on. His stance
Speaker 3: is clear. Although technological extraterrestrial intelligences might be rare, there
Speaker 3: is only one way to really find out, and that
Speaker 3: is by searching for it.
Speaker 2: So the low probability doesn't mean we stop looking.
Speaker 3: Absolutely not. The scientific imperative remains because think about the outcomes. Okay,
Speaker 3: if we keep searching with better telescopes, better techniques and
Speaker 3: we find nothing, well, that silence becomes data. It strengthens
Speaker 3: the case for rarity, It sharpens our understanding of the
Speaker 3: specific conditions needed for life like ours, and it underscores
Speaker 3: our own potential uniqueness. That in itself is a profound
Speaker 3: scientific insight.
Speaker 2: Finding nothing tells us something important exactly.
Speaker 3: But if if we search and we do find something thing,
Speaker 3: a clear, verifiable signal evidence of another technological mind.
Speaker 2: Out there, that would change everything.
Speaker 3: It would arguably be the single biggest scientific breakthrough in
Speaker 3: human history. We would know, finally, definitively that we are
Speaker 3: not alone. It would reshape our understanding of biology, of cosmology,
Speaker 3: of our own place in the universe forever.
Speaker 2: So the search is worthwhile, regardless of the outcome. Find
Speaker 2: nothing we learn about rarity, find something we learn We're
Speaker 2: not alone.
Speaker 3: That's the beauty of the scientific quest.
Speaker 2: So what does this all mean for you? Listening right now?
Speaker 2: Next time you look up at the stars. Does thinking
Speaker 2: about these odds, this potential rarity, make the universe feel
Speaker 2: I don't know, emptier well perhaps, Or does it make
Speaker 2: our own existence here on Earth feel even more extraordinary,
Speaker 2: like we won an unbelievable cosmic lottery? Does it highlight
Speaker 2: the sheer improbability, the incredible chain of events planetary atmospheric
Speaker 2: evolutionary that had to happen just right for us to
Speaker 2: be here.
Speaker 3: Having this conversation, it's certainly gives you a different perspective
Speaker 3: on Earth.
Speaker 2: Maybe the most profound takeaway isn't just about searching for them,
Speaker 2: but about appreciating us, appreciating the astonishing, perhaps fragile reality
Speaker 2: of our own technological civilization, and maybe just maybe realizing
Speaker 2: the immense value we should place on ensuring its continued existence.
Speaker 4: Something to think about the passa
Speaker 3: Yousssssss