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: You know, I was standing outside the other night. It
Speaker 2: was a really clear sky, no moon, and I was
Speaker 2: doing that thing we all do. I was just looking
Speaker 2: up at the Milky Way. And when you look at that,
Speaker 2: that sort of band of light. You know the numbers.
Speaker 2: You've heard them a million times. There are what somewhere
Speaker 2: between one hundred and four hundred billion stars just in
Speaker 2: our galaxy.
Speaker 3: Alone, and almost incomprehensible number.
Speaker 2: It really is. And you know, statistically, even if life
Speaker 2: is a one in a billion shot, the sky should
Speaker 2: just be buzzing with activity, should be like times square
Speaker 2: on New Year's Eve up there.
Speaker 3: But it's not. It's quiet.
Speaker 2: It's dead quiet. And that's the Fermi paradox, isn't it.
Speaker 2: It's the ghost that haunts modern astronomy.
Speaker 3: It is the great silence, the question that underpins everything
Speaker 3: we do. When we look at the stars, where is
Speaker 3: everybody exactly?
Speaker 2: It's the question that keeps us up at night. And
Speaker 2: for the last what sixty or seventy years, ever since
Speaker 2: Frank Drake first wrote down his famous equation, we've been
Speaker 2: trying to answer it.
Speaker 3: We've been listening with massive radio telescopes.
Speaker 2: Yeah, we've been scanning for radio waves, looking fordyce in spheres,
Speaker 2: hunting for laser pulses from some advanced civilization. And the
Speaker 2: silence is just well, it's deafening.
Speaker 3: It's profoundly unsettling because all the math, all the logic,
Speaker 3: it says we shouldn't.
Speaker 2: Be alone, right, And usually when we try to explain
Speaker 2: that silence, we tend to blame you know, biology, We say,
Speaker 2: maybe life is just incredibly rare, or maybe the jump
Speaker 2: from single cell to multi celled life is the big hurdle.
Speaker 3: Or we blame politics, you know, the idea that civilizations
Speaker 3: get powerful enough to invent nuclear weapons and then they
Speaker 3: just they wipe themselves out before they ever get to
Speaker 3: the star.
Speaker 2: Great filter, But today we're looking at some research that
Speaker 2: points the finger at something else, entirely, something so mundane,
Speaker 2: so dirty, and so terrestrial. We almost never think about
Speaker 2: it in the context of aliens.
Speaker 3: Yeah, we're not talking about DNA, and we're not talking
Speaker 3: about nuclear war. We're talking about rocks.
Speaker 2: Specifically, we are talking about coal.
Speaker 3: It sounds almost ridiculous when you say it out loud,
Speaker 3: doesn't it that the key to interstellar communication to the
Speaker 3: highest tier of technology might depend on this black, sooty
Speaker 3: rock that we are currently trying desperately to stop using.
Speaker 2: It feels completely counterintuitive. But this new paper from the
Speaker 2: International Journal of Astrobiology, led by Lincoln Taiz, it makes
Speaker 2: a really compelling, almost disturbing case. They argue that we
Speaker 2: might be alone, not because life is rare, but because
Speaker 2: the Industrial Revolution is a kind of geological lottery ticket
Speaker 2: that most planets just never get to care in.
Speaker 3: Precisely, the core premise is that you can have a
Speaker 3: planet absolutely teeming with life, you can have smart, philosophical,
Speaker 3: artistic creatures, but if they don't have access to massive,
Speaker 3: easily accessible energy, dense deposits of fossil fuels and specifically coal,
Speaker 3: they will never break through a certain technological glass ceiling.
Speaker 2: They'll never build a radio telescope.
Speaker 3: I'll never build a radio telescope. They will never say hello.
Speaker 2: So our mission today is to really unpack this idea.
Speaker 2: We need to understand why a lump of coal is
Speaker 2: actually a piece of advanced technology and disguise why our
Speaker 2: planet Earth got lucky enough to have it. And you
Speaker 2: know what this all means for the search for extraterrestrial intelligence.
Speaker 3: We're going to be talking about something called the energy ladder,
Speaker 3: and I should warn you this might make you look
Speaker 3: at something as simple as a rusted steel beam or
Speaker 3: even a cloudy sky with a completely different level of respect.
Speaker 2: Okay, let's start with the basics. Then I want to
Speaker 2: play the skeptic immediately, because I know you listening are
Speaker 2: probably thinking it. I'm certainly thinking it. We're talking about starships, supercomputers,
Speaker 2: massive SETI arrays, high tech stuff, and you're telling me
Speaker 2: the prerequisite for all of that is burning dead plants.
Speaker 2: It feels like we're mixing up our eras. Why is
Speaker 2: the dirty, primitive stuff a hard requirement for the clean
Speaker 2: advanced stuff.
Speaker 3: It's a totally valid skepticism. It feels like a paradox.
Speaker 3: But to really get it, we have to look at
Speaker 3: what these authors call the energy ladder, and you have
Speaker 3: to think of technological progress not as some you know,
Speaker 3: smooth upward slope where you just slowly get smarter and
Speaker 3: build better things. Right, think of it as a series
Speaker 3: of very high, very distinct steps. To get to the
Speaker 3: top where you have silicon chips and satellites and solar panels,
Speaker 3: you have to be standing firmly on the step just
Speaker 3: below it, And the step right below our silicon age
Speaker 3: is the steel age.
Speaker 2: Steel, Okay, I get that. Okay, I mean we use
Speaker 2: steel for everything. If I look out my window right now,
Speaker 2: every building, every car, every bridge, it all involves steel.
Speaker 2: But humans were making metal long before the Industrial revolution.
Speaker 2: Right of course, we had the Bronze age with the
Speaker 2: iron age. We are making swords and plows using charcoal
Speaker 2: from wood fires thousands and thousands of years ago. Why
Speaker 2: couldn't an alien civilization just keep doing that? Why couldn't
Speaker 2: they just scale that up and build a radio telescope
Speaker 2: using wood fired iron?
Speaker 3: And this is where the physics gets really mean, it
Speaker 3: all comes down to two things, scale and heat. Yes,
Speaker 3: you can smelt iron with charcoal, humans did it for millennia.
Speaker 3: But charcoal as a fuel source for an industrial civilization
Speaker 3: has two fatal flaws.
Speaker 2: Okay, what are they?
Speaker 3: First, it's just not energy dense enough. You have to
Speaker 3: burn a staggering amount of forest to get a relatively
Speaker 3: small amount of metal. You would effectively have to DeForest
Speaker 3: your entire continent just to build one major city. The
Speaker 3: energy retun on investment is.
Speaker 2: Terrible, right, You run out of fuel pretty quickly.
Speaker 3: Very quickly. But the second problem is a structural one,
Speaker 3: and this is the one people almost never think about.
Speaker 2: Structural You mean the charcoal itself exactly.
Speaker 3: To mass produce the kind of steel you need for
Speaker 3: skyscrapers or massive ships or launch pads, you need a
Speaker 3: blast furnace, a massive towering structure, sometimes ten stories high,
Speaker 3: that you feed iron ore into from the top. Okay,
Speaker 3: if you fill a giant blast furnace with regular wood
Speaker 3: charcoal and then dump tons and tons of heavy iron
Speaker 3: ore on top of it, what do you think happens
Speaker 3: to the charcoal at the bottom.
Speaker 2: It would get crushed. Yeah, because charcoal is brittle, it's
Speaker 2: just burnt wood.
Speaker 3: It gets crushed into dust. It crumbles, and when that
Speaker 3: charcoal turns to dust, it chokes the fire. Air can't
Speaker 3: circulate up through the stack. The combustion process just stops.
Speaker 3: The furnace dies.
Speaker 2: So you physically cannot build a massive blast furnace using
Speaker 2: wood charcoal.
Speaker 3: You can't. You hit a hard physical limit on how
Speaker 3: big you can go, which means you hit a limit
Speaker 3: on how much steel you can produce. Your civilization's growth
Speaker 3: literally crumbles under its own weight.
Speaker 2: So you're saying you can't build the infrastructure of a
Speaker 2: modern city with wood. The fuel itself breaks right, You
Speaker 2: are stuck.
Speaker 3: You'll hit a physical limit on production. To go bigger,
Speaker 3: to get hotter, you need a fuel that is harder, hotter,
Speaker 3: and stronger. You need coke.
Speaker 2: And just to clarify for everyone, we are not talking
Speaker 2: about the soda.
Speaker 3: No, definitely not coke. Coke is a processed fuel made
Speaker 3: from coal. You take bituminous coal and you bake it
Speaker 3: in an oxygen free oven. This process, called coking, burns
Speaker 3: off all the impurities, the water, the tar, the volol gases,
Speaker 3: and what you're left with is almost pure concentrated carbon.
Speaker 2: Specially about that.
Speaker 3: It's hard, it's porous, and it burns incredibly hot and consistently.
Speaker 3: But most importantly, it's strong. It has what engineers call
Speaker 3: crush strength.
Speaker 2: Crush strength.
Speaker 3: It can support the weight of hundreds of tons of
Speaker 3: iron ore stacked on top of it in a blast
Speaker 3: furnace without crumbling into dust.
Speaker 2: That is such a specific mundane detail. The crush strength
Speaker 2: of the fuel determines the size of.
Speaker 3: The civilization, It really really does. So coke allows you
Speaker 3: to build the mega furnaces. The mega furnaces give you cheap,
Speaker 3: high quality steel in absolutely massive quantities, and that is
Speaker 3: the gateway. This is the Domino effect that the paper describes.
Speaker 3: And I think it's worth walking through this chain because
Speaker 3: it's fascinating just how tightly connected it all is.
Speaker 2: Okay, let's do it. Domino number one.
Speaker 3: Domino one, you have massive and critically accessible coal deposits
Speaker 3: on your planet.
Speaker 2: Okay, So step one is just the geology. You have
Speaker 2: to be born on a lucky planet.
Speaker 3: Domino two, that coal allows you to create coke, which
Speaker 3: in turn allows you to create mass produced steel.
Speaker 2: Got it. Step two is the metallurgy. We now have
Speaker 2: the steel.
Speaker 3: Domino three, what is the single most important thing you
Speaker 3: make with that new high strength steel? And it's not swords,
Speaker 3: it's not armor. It's drill bit drill bits.
Speaker 2: Okay, that's unexpected. I was thinking maybe steam engines or
Speaker 2: train tracks.
Speaker 3: Oh, those are hugely important, don't get me wrong. But
Speaker 3: the drill bit is the true pivot point of the
Speaker 3: twentieth century. Because why do you need high strength, industrial
Speaker 3: steel drill bits to get to Domino four deep pressurized
Speaker 3: geological reserves of oil and natural gas.
Speaker 2: Oh okay, I see where this is going. It's all
Speaker 2: about depth.
Speaker 3: It is exactly about depth. The coal that kicked off
Speaker 3: our industrial revolution in places like England and Pennsylvania, it
Speaker 3: was often right at the surface. You could literally pick
Speaker 3: it up off the ground or dig it out with
Speaker 3: a shovel and a bucket. It was the low hanging
Speaker 3: fruit of energy.
Speaker 2: Right. You didn't need high tech to get the first.
Speaker 3: Energy source exactly. But oil isn't like that. You don't
Speaker 3: just you know, find a pool of crude oil sitting
Speaker 3: in the woods.
Speaker 2: No, it's deep underground, very deep.
Speaker 3: The crude oil that powered the twentieth century, the stuff
Speaker 3: that gave us cars and planes and massive electricity grids,
Speaker 3: is usually trapped thousands, sometimes tens of thousands of feet underground,
Speaker 3: and it's often under incredibly hard capstones of rock like
Speaker 3: granite or limestone.
Speaker 2: And you can't get through that with a pick axe.
Speaker 3: You can't get to it with a pickaxe. You can't
Speaker 3: get to it with a wooden rig. You need hardened
Speaker 3: steel pipes and drill bits tipped with industry diamonds or
Speaker 3: tungsten carbide to puncture the earth deep enough to tap
Speaker 3: that incredible energy source.
Speaker 2: So if you don't have the coal to make the steel,
Speaker 2: you can never drill deep enough to get the oil.
Speaker 3: And if you don't get the oil, you never get
Speaker 3: the internal combustion engine, You never get the petrochemical industry.
Speaker 3: You don't get the plastics and the insulators you need
Speaker 3: for advanced electronics, and ultimately you never get the radio telescope.
Speaker 2: So it really is a technological glass ceiling. You might
Speaker 2: have geniuses on your planet. They might know the math,
Speaker 2: they might understand the theory of radio waves. They might
Speaker 2: have the blueprints for a receiver sitting on a desk,
Speaker 2: but you physically cannot build the machine.
Speaker 3: You can't because you lack the materials to extract the
Speaker 3: next level of materials.
Speaker 2: You're stuck.
Speaker 3: You are stuck in a wood and iron age. Maybe
Speaker 3: you build great sailing ships, maybe you develop incredible clockwork mechanisms.
Speaker 3: Maybe you have breathtaking architecture using stone and basic metals,
Speaker 3: but you are not launching satellites. You are not building microprocessors.
Speaker 2: That is a wild realization. We usually think of technology
Speaker 2: as just being about knowledge. If we know how to
Speaker 2: do it, we can build it. But this paper argues
Speaker 2: that technology is fundamentally material. It's resource dependent.
Speaker 3: Knowledge without the calorie density to actually apply it on
Speaker 3: a massive scale is just philosophy. The authors argue that
Speaker 3: fossil fuels and coal specifically are the only energy source
Speaker 3: that is both dense enough and accessible enough to a
Speaker 3: pre industrial society to bootstrap the whole system. Yeah, the
Speaker 3: starter fluid and the starter fluid for the engine of civilization.
Speaker 3: Without it, the engine never turns over.
Speaker 2: I want to push back on this though. I feel
Speaker 2: like we're being very deterministic here. We're essentially saying there
Speaker 2: is only one path, but surely the universe is full
Speaker 2: of variables. Let's play Devil's advocate, because I can hear
Speaker 2: the counter argument screaming in my head. Right now, go
Speaker 2: for it. We are humans. We were messy, we were inefficient,
Speaker 2: We burned the coal, We choked our cities with smog.
Speaker 2: We heated the planet. But couldn't an alien species just
Speaker 2: be better than us?
Speaker 3: Alien hypothesis, the eco friendly.
Speaker 2: Et, right, couldn't they be smarter? Couldn't they look at
Speaker 2: a lump of coal, analyze the chemistry, realized it's going
Speaker 2: to mess up their atmosphere and just say, you know what,
Speaker 2: no thanks. Why couldn't they skip the entire dirty phase
Speaker 2: and go straight to wind, water, solar or geothermal? Why
Speaker 2: do they have to burn the rocks?
Speaker 3: It is a very very appealing thought. We want to
Speaker 3: believe that pollution isn't a necessary step. It comforts us
Speaker 3: to think there's a cleaner, smarter way. But the paper
Speaker 3: addresses this idea head on, and they argue it's a
Speaker 3: classic chicken and egg problem.
Speaker 2: How so a chicken and egg?
Speaker 3: Okay, let's look at a modern wind turbine, one of
Speaker 3: those big three megawat ones. It looks clean, right, it's elegant,
Speaker 3: It spins in the breeze, generates electricity, no smoke, beautiful,
Speaker 3: But what is it actually made of?
Speaker 2: Well, the tower is steel, massive sections of.
Speaker 3: Steel, hundreds of tons of high grade steel, which, as
Speaker 3: we've already established, needs a blast furnace burning coke to produce.
Speaker 3: What about the blades.
Speaker 2: I think there's some kind of composite.
Speaker 3: Fiberglass, usually carbon fiber or fiberglass resins. And where do
Speaker 3: those come from? They are petrochemicals. They are derived from
Speaker 3: oil and natural gas.
Speaker 2: So the blades of a clean wind turbine are made of.
Speaker 3: Oil essentially, yes, And that's not all what's inside? Then,
Speaker 3: to sell the generator at the top, it means incredibly
Speaker 3: powerful rare earth magnets like neodymium to work efficiently. Mining
Speaker 3: and refining rare earth metals is one of the most
Speaker 3: energy intensive and chemically harsh processes we have. You have
Speaker 3: to move literal mountains of rock to get just a
Speaker 3: few kilograms of metal.
Speaker 2: And how do you moot all that rock.
Speaker 3: With massive diesel power dump trucks and excavators which are
Speaker 3: made of steel and run on oil. Do you see
Speaker 3: the problem. You cannot build a wind turbine with stone tools.
Speaker 3: You can't even build it with blacksmith's tools from the
Speaker 3: iron age.
Speaker 2: You need the dirty machine to build the clean machine.
Speaker 3: That is the catch twenty two. To build the clean
Speaker 3: energy infrastructure of the twenty first century, solar panels, nuclear reactors,
Speaker 3: hydroelectric dams. You need an industrial base that is already
Speaker 3: capable of precision manufacturing, heavy global transport, and high heat metallurgy.
Speaker 2: It's like trying to build a computer when all you
Speaker 2: have is a hammer and a log.
Speaker 3: Solar panels are another perfect example. To make a modern
Speaker 3: photovoltaic cell, you need silicon that is ninety nine point
Speaker 3: nine nine nine nine percent pure. We call it electronic
Speaker 3: grade silicon. To get silicon that pure, you have to
Speaker 3: start with quartz sand and melt it down. Do you
Speaker 3: have any idea how hot you have to get quartz
Speaker 3: sand to melt it.
Speaker 2: I'm guessing pretty hot.
Speaker 3: Around thirty five hundred degrees fahrenheit or about nineteen hundred celsius.
Speaker 3: You cannot do that with a wood fire. You can't
Speaker 3: do it with a magnifying glass. You need massive industrial
Speaker 3: arc furnaces that consume incredible amounts of electricity.
Speaker 2: And where does the electricity for those first furnaces come from?
Speaker 2: In a developing civilization.
Speaker 3: It has to come from something that burns. If you're
Speaker 3: a pre industrial society, you don't have the solar panels
Speaker 3: yet to power the furnace to make the solar panels,
Speaker 3: it's a paradox. You have to burn the stored sunlight
Speaker 3: of the past coal to build a technology that can
Speaker 3: catch the sunlight of the present.
Speaker 2: So if you're an alien on a planet without coal,
Speaker 2: you might theoretically understand how his solar panel works. You
Speaker 2: could write down the physics, but you are trapped by
Speaker 2: the energy limitations of wood and muscle power.
Speaker 3: Exactly, you can never generate the massive surplus energy needed
Speaker 3: to build the next rung of the latter. You're stuck
Speaker 3: in an energy poverty loop. The authors are very clear
Speaker 3: on this point. An advanced technological civilization what they call
Speaker 3: an ATC, must pass through a fossil fuel phase. They
Speaker 3: believe there is likely no shortcut.
Speaker 2: Wow, that implies that every advanced civilization in the universe,
Speaker 2: if they exist, has had to deal with climate change.
Speaker 2: They've all had smog, They've all had their own version
Speaker 2: of Victorian London or twentieth century Pittsburgh.
Speaker 3: It becomes a universal filter. If you want to reach
Speaker 3: for the stars, you have to get your hands dirty first.
Speaker 2: Okay, so we've established the need an ATC needs coal
Speaker 2: to get off the ground. But here's the part that
Speaker 2: still confuses me. Coal is just dead plants right.
Speaker 3: Essentially, yes, it's fossilized terrestrial plant matter.
Speaker 2: So if we assume that life is somewhat common out there,
Speaker 2: if we assume there are other planets with forests or
Speaker 2: jungles or whatever their equivalent is, wouldn't they all have coal?
Speaker 2: Why would this be a filter? If you have trees,
Speaker 2: don't you automatically get coal?
Speaker 3: And here is where we pivot from engineering to geology.
Speaker 3: This is the part of the paper that really blew
Speaker 3: my mind. The answer is a resounding no. Just having
Speaker 3: trees does not guarantee you get coal. In fact, on Earth,
Speaker 3: the formation of the coal that powered our world was
Speaker 3: a bizarre anomaly. It wasn't the rule. It was the
Speaker 3: wild exception.
Speaker 2: An anomaly. I always thought it was just what happens
Speaker 2: when trees die and get buried.
Speaker 3: Not usually think about a forest today. A tree falls
Speaker 3: in the Amazon or even in your backyard. What happens
Speaker 3: to it? Over time?
Speaker 2: It rots, you know, termites eat it, fungi and bacteria
Speaker 2: break it down. Eventually it just becomes part of the soil.
Speaker 3: Exactly. The carbon is recycled. It's released back into the
Speaker 3: ape atmosphere as CO two by the decomposers. It doesn't
Speaker 3: get buried, it doesn't become a rock. But starting about
Speaker 3: three hundred and sixty million years ago, during the Carboniferous period,
Speaker 3: something very different happened.
Speaker 2: The Carboniferous the coal bearing period. I guess the name
Speaker 2: says it all.
Speaker 3: It really does. There were two massive, unique factors that
Speaker 3: align perfectly to create something like ninety percent of all
Speaker 3: the coal we used today. Ninety percent in one specific
Speaker 3: window of geologic time.
Speaker 2: Okay, what was factor one?
Speaker 3: Factor one was biological trees had just invented a new
Speaker 3: revolutionary molecule called lignin.
Speaker 2: Lignin that's the stuff that makes wood hard, right, It's
Speaker 2: what allows a tree to grow one hundred feet tall
Speaker 2: without just flopping over like a piece of spaghetti.
Speaker 3: Correct. It's the structural armor of the plant world. It's
Speaker 3: incredibly tough stuff. When lignin first appeared in the evolutionary timeline,
Speaker 3: there was a problem. And here's the kicker. For about
Speaker 3: forty to sixty million years, nothing on Earth knew how
Speaker 3: to eat it.
Speaker 2: Wait, really, the bacteria couldn't digest it. The fun guy,
Speaker 2: the white rot.
Speaker 3: Fungi, the specific family of mushrooms and bacteria that are
Speaker 3: experts at breaking down wood today simply hadn't evolved yet.
Speaker 3: There was a huge evolutionary lag. So when these massive
Speaker 3: primitive trees died and fell over, they didn't rot, they
Speaker 3: just sat there.
Speaker 2: That is a wild image a world where dead trees
Speaker 2: just pile up like garbage because nature hasn't invented the
Speaker 2: garbage disposal yet.
Speaker 3: That's a perfect analogy. Imagine walking through a forest where
Speaker 3: every single tree that had fallen for the last million
Speaker 3: years is still there, just piled up hundreds of feet
Speaker 3: deep in some places. But that alone isn't enough to
Speaker 3: make coal. If they just sit on the surface, will
Speaker 3: eventually oxidize or dry out or burn in a forest fire.
Speaker 2: So you need to bury them.
Speaker 3: You need to bury them fast and deep. And that
Speaker 3: brings us to factor two.
Speaker 2: Plate tectonics, the moving continents.
Speaker 3: Specifically the collision of continents. During this exact time period,
Speaker 3: the super continent of Pangaea was forming. The ancient continents
Speaker 3: of Gondwana and Larussia were smashing into each other in
Speaker 3: slow motion.
Speaker 2: And that created mountains like the Appalachians.
Speaker 3: It created mountains, yes, but it also created the opposite
Speaker 3: of mountains. It created deep, rapidly sinking basins right next
Speaker 3: to the new mountain ranges. They're called foreland basins explained
Speaker 3: foreland basin for us. Think of it like this. If
Speaker 3: you put a heavy weight on a mattress, the mattress
Speaker 3: SAgs down around the weight. When you build a huge
Speaker 3: mountain range, its immense weight pushes down the edge of
Speaker 3: the tectonic plate next to it, creating a long, deep
Speaker 3: trough or basin. During the Carboniferous you had these massive,
Speaker 3: swampy tropical basins forming right next to the rising mountains.
Speaker 3: So these lignan rich trees would fall into the water,
Speaker 3: sink into the anaerobic mud with no oxygen, and then
Speaker 3: be rapidly buried by tons of sediment and rock washing
Speaker 3: down from the eroding mountains.
Speaker 2: So they were sealed off.
Speaker 3: Preserved perfectly sealed off from the air, then compressed by
Speaker 3: miles of rock above them, and cooked by the earth
Speaker 3: geothermal heat for millions of years. That specific pressure cooker
Speaker 3: environment is what turned the wood into coal.
Speaker 2: And this only happened because of that specific combination. The
Speaker 2: wood eating fung guy weren't there yet, and the continents
Speaker 2: were smashing together in just the right way to create
Speaker 2: these burial pits.
Speaker 3: Yes, and eventually the fung gui did evolve to eat lignin.
Speaker 3: The coal window slam shut. If you look at the
Speaker 3: lush forests from the Jurassic or the Cretaceous, the age
Speaker 3: of dinosaurs, they didn't leave behind coal deposits that were
Speaker 3: nearly as massive or high quality as the carboniferous ones.
Speaker 3: Why not, because by then the wood was rotting away
Speaker 3: on the forest floor before it ever had a chance
Speaker 3: to be buried. The cosmic garbage disposal had finally been invented.
Speaker 2: That is incredible luck. So let's apply this to an
Speaker 2: alien planet. You could have a world with lush jungles
Speaker 2: that have existed for a billion years. Yeah, But if
Speaker 2: they never had that biological lag where the decomposers couldn't
Speaker 2: eat the trees, or if they don't have active pleat
Speaker 2: tectonics to create those deep basins.
Speaker 3: Then the dead trees just wrought. They returned to the
Speaker 3: carbon cycle. They never formed the dense, concentrated energy banks
Speaker 3: needed for an industrial revolution.
Speaker 2: And the civilization on that planet is just out of luck.
Speaker 3: They might have plenty of wood, they can burn it
Speaker 3: to stay warm and cook their food, but they will
Speaker 3: never find the thick black seams of high density coal
Speaker 3: needed to smelt steel and bootstrap a technological society.
Speaker 2: It implies that active geology is a hard requirement for
Speaker 2: intelligent life to become technological life. A planet like Mars,
Speaker 2: for instance, Mars is mostly geologically dead, isn't it.
Speaker 3: For the most part, Yes, Mars has what geologists call
Speaker 3: stagnant lid tectonics. Its crust is one solid piece. It
Speaker 3: doesn't have plates crashing together and subducting and creating these
Speaker 3: deep burial basins. So even if Mars had dense forests
Speaker 3: billions of years ago, it probably didn't create the kind
Speaker 3: of deep, rich coal reserves needed for industry.
Speaker 2: This really adds a whole new, powerful layer to the
Speaker 2: rare earth hypothesis. Is not just rare life, rare tectonics,
Speaker 2: and rare fungi evolution.
Speaker 3: But wait, because there is another layer to this onion.
Speaker 3: It gets even more specific. It's not just about space
Speaker 3: and geology. It is about time.
Speaker 2: Time. What do you mean?
Speaker 3: The paper raises an incredibly important question about what they
Speaker 3: call synchronicity. It's the race between evolution and geology.
Speaker 2: Okay, explain that concept.
Speaker 3: Think about coal like a slow cooked meal. Like a
Speaker 3: brisket and a smoker. You can't just put it in
Speaker 3: the oven and take it out five minutes later and
Speaker 3: expect it to be good. It takes time to be ready.
Speaker 2: I'm hungry now, but go on, I'm with you.
Speaker 3: The plant matter that gets buried starts as peat. Pete
Speaker 3: is okay. You can dig it up and burn it
Speaker 3: people in Ireland and Scotland did for centuries. But it's wet,
Speaker 3: it's smoky, and it has a very low energy density.
Speaker 2: Not nearly enough for a blast.
Speaker 3: Furnace, nowhere near enough. Over millions of years, the heat
Speaker 3: and pressure from those overlying rocks bake the peat. It
Speaker 3: turns into lignite or brown coal. That's a bit better.
Speaker 3: Then it cooks more and turns into subituminous coal. Finally,
Speaker 3: after a very long time, it becomes high quality by
Speaker 3: two minus coal and eventually anthracite.
Speaker 2: That's the good stuff.
Speaker 3: That is the good stuff. That is the energy dense,
Speaker 3: high carbon rock you need for making coke and steel.
Speaker 2: So the coal has to cook, it has to mature,
Speaker 2: it has.
Speaker 3: To cook, and on Earth that cooking time was on
Speaker 3: average somewhere between one hundred and three hundred million years
Speaker 3: now look at our timeline. The carboniferous laid down the
Speaker 3: peat about three hundred to three hundred and sixty million
Speaker 3: years ago. It spent that whole time cooking, and just
Speaker 3: as it reached peak maturity, who shows up on the scene.
Speaker 2: Homo sapiens. We walked into the kitchen right when the
Speaker 2: timer went exactly.
Speaker 3: We arrived at the perfect moment. But consider the alternative.
Speaker 3: What if an intelligent species had evolved on Earth much earlier,
Speaker 3: say in the Triassic Period, alongside the first dinosaurs around
Speaker 3: two hundred million years ago, a.
Speaker 2: Smart dinosaur civilization, the Silurians.
Speaker 3: Right, if these intelligent dinosaurids had started digging in the
Speaker 3: ground looking for fuel, the coal from the carboniferous would
Speaker 3: have only been cooking for what maybe one hundred or
Speaker 3: one hundred and fifty million years.
Speaker 2: It would still be lignite or pete. It wouldn't be ready.
Speaker 3: Exactly, so they would try to burn it. They would
Speaker 3: try to build big furnaces and make steel, but the
Speaker 3: fire wouldn't get hot enough, the fuel would crush under
Speaker 3: the weight of the ore. They would hit the exact
Speaker 3: same physical limit we talked about, and.
Speaker 2: They would probably just give up. They'd conclude it was impossible.
Speaker 3: They would be forced to give up their entire civilization,
Speaker 3: would be stuck in a pre industrial state simply because
Speaker 3: the planet's fuel hadn't finished cooking yet.
Speaker 2: That is terrifyingly specific. Yeah, so you need the biology
Speaker 2: to make the trees with lignin, You need the geology
Speaker 2: of plate tectonics to bury them. You need hundreds of
Speaker 2: millions of years of time for them to cook, and
Speaker 2: then you need intelligent life to.
Speaker 3: Evolve, and you need that intelligent life to evolve after
Speaker 3: the cooking is done, but before the coal is destroyed.
Speaker 3: Coal seams don't last forever over geologic time. They get
Speaker 3: pushed up by tectonic forces in a road away, or
Speaker 3: they get subducted back into the mantle. There's a temporal window.
Speaker 2: If you miss the window, you miss your chance to
Speaker 2: go to the stars.
Speaker 3: Lincoln Tayiz, the author, calls it synchronicity. The resources and
Speaker 3: the user of the resources must coincide in time and space.
Speaker 3: If they don't, the planet remains silent.
Speaker 2: So this brings us back to the search to the
Speaker 2: Fermi paradox. If this theory is right, we shouldn't just
Speaker 2: be listening for radio beeps from the sky, we should
Speaker 2: be looking for smoke signals.
Speaker 3: In a way. Yes, the paper suggests a new and
Speaker 3: very different strategy for searching for ATC's advanced technological civilizations.
Speaker 3: Instead of just listening, we should be looking at the
Speaker 3: atmospheres of exoplanets for the chemical signatures of an industrial revolution.
Speaker 2: What does an industrial revolution even look like? From light
Speaker 2: years away?
Speaker 3: It looks like a chemical mess, a very specific, unnatural mess.
Speaker 3: If a civilization is burning massive amounts of bituminous coal
Speaker 3: to bootstrap their technology, their atmosphere is going to be
Speaker 3: flooded with specific industrial byproducts.
Speaker 2: Probably bioxide obviously would be a big one.
Speaker 3: Yes, high level of CO two. But a planet can
Speaker 3: have high CO two naturally. Look at Venus. Its atmosphere
Speaker 3: is basically all CO two, So that on its own
Speaker 3: isn't enough to say aliens. You need the whole unnatural.
Speaker 2: Mix, the cocktail of pollutants exactly.
Speaker 3: You look for high levels of sulfur dioxide from burning
Speaker 3: sulfur rich coal. You look for nitrogen oxides from high
Speaker 3: temperature combustion. You look for aerosols of heavy metals like
Speaker 3: mercury and lead, And specifically, you look for soot.
Speaker 2: Soot, carbon particulates. Can we actually see soot in an
Speaker 2: atmosphere from that far away.
Speaker 3: With the next generation of space telescopes, the successors to
Speaker 3: James Web, Yes, it should be possible. We use a
Speaker 3: technique called transit spectroscopy. We wait for the planet to
Speaker 3: pass in front of its star from our point of view.
Speaker 2: And the starlight filters through the planet's.
Speaker 3: Air right and different chemicals in that air absorb different
Speaker 3: very specific colors or wavelengths of light. If we analyze
Speaker 3: that filtered light and see the absorption lines for CO
Speaker 3: two and sulfur dioxide, nitrogen oxides, and the broad dimming
Speaker 3: effect of soot all peaking at the same.
Speaker 2: Time, that's a combination that nature doesn't really create on
Speaker 2: its own.
Speaker 3: It's very very hard for nature to do that. Volcanoes
Speaker 3: produce sulfur, and forest fires produce soot, but to see
Speaker 3: all of them sustained at high levels all at once
Speaker 3: strongly implies artificial industrial scale combustion.
Speaker 2: So we are literally looking for a planet that looks
Speaker 2: like Pittsburgh in nineteen twenty or Beijing in the early
Speaker 2: two thousands.
Speaker 3: We're looking for a smoggy world. But and here is
Speaker 3: the really tough part, the great filter aspect of this.
Speaker 3: There's a huge catch. The window to spot this is
Speaker 3: incredibly small.
Speaker 2: Because the industrial phase doesn't last forever.
Speaker 3: It can't think about our own history. We started burning
Speaker 3: coal heavily in say the mid eighteen hundreds. We are
Speaker 3: now roughly two hundred years later, trying as hard as
Speaker 3: we can to transition away from it. We're moving toward nuclear, solar,
Speaker 3: and hopefully fusion.
Speaker 2: So the smog is just a temporary state of being
Speaker 2: for civilization.
Speaker 3: Bill. Yes, there are two outcomes for a coal burning civilization.
Speaker 3: Either they destroy their planet with the pollution and go extinct,
Speaker 3: in which case their signal dies out, or they succeed,
Speaker 3: they use the energy from coal to build the clean
Speaker 3: tech and they stop burning the coal.
Speaker 2: So either way, the subclears, the subclears.
Speaker 3: The sulfur dioxide rains out, the signal fades. The authors
Speaker 3: of the paper estimate that this detectable industrial phase might
Speaker 3: only last for five hundred to one thousand years pops.
Speaker 2: Five hundred years in the four and a half billion
Speaker 2: year life span of a planet. That is a blink
Speaker 2: of an eye.
Speaker 3: It's less than a nanosecond in cosmic time. If the
Speaker 3: universe is thirteen point eight billion years old, the odds
Speaker 3: of us happening to point our telescope aout another planet
Speaker 3: during that specific fleeting five hundred year window of its
Speaker 3: entire history are statistically well, they're incredibly small.
Speaker 2: It's like trying to take a picture of a firework
Speaker 2: exactly at the moment it explodes. If you look a
Speaker 2: second too early, there's nothing but a rocket trail. If
Speaker 2: you look a second too late, it's just smoke fading
Speaker 2: away in the dark.
Speaker 3: That's a perfect analogy, and this might explain why we
Speaker 3: haven't found anyone. The primitive civilizations are invisible because they
Speaker 3: aren't burning anything, and the super advanced civilizations are invisible
Speaker 3: because they've moved on to clean, sustainable energy sources. We
Speaker 3: can only see the ones currently in the dirty teenage
Speaker 3: years of their technological development.
Speaker 2: It makes the search feel so much harder. But in
Speaker 2: another way, it really refines that we know exactly what
Speaker 2: we're looking for now, even if it's rare.
Speaker 3: It does it reframes the Great Silence not as a
Speaker 3: mystery of biology, but as a challenge of timing.
Speaker 2: So let's zoom out. Let's talk about the big picture,
Speaker 2: What does this all mean for us, for a place
Speaker 2: in the universe. We used to talk about the rarer
Speaker 2: Earth hypothesis as being all about biology. We thought, maybe
Speaker 2: making the first living cell is the hard.
Speaker 3: Part, right. The great hurdle was always assumed to be
Speaker 3: the origin of life itself, the jump from non living
Speaker 3: chemistry to a reproducing cell.
Speaker 2: But this paper kind of flips that on its head.
Speaker 2: It suggests that, you know what, maybe life is common.
Speaker 2: There might be planets every where with moss and trees
Speaker 2: and maybe even smart animals running around.
Speaker 3: But they're stuck. Think about it. There could be brilliant
Speaker 3: aquatic civilizations living in global oceans, creatures as smart as us,
Speaker 3: maybe even smarter. But can you smelt steel underwater?
Speaker 2: No, you can't even build a fire underwater, exactly.
Speaker 3: So, they will never build a steam engine. They will
Speaker 3: never invent the transistor. They will never build a spaceship.
Speaker 3: They might be incredible philosophers and poets of the deep,
Speaker 3: but they will never call us.
Speaker 2: Or what about civilizations on dry, rocky planets that never
Speaker 2: had the right kind of plate tectonics. They might have
Speaker 2: amazing cultures. They might be brilliant astronomers, with glass telescopes,
Speaker 2: looking up at the stars and wondering if they're alone.
Speaker 3: But they can't leave. They are trapped by their geology.
Speaker 3: They lack the starter fluid, They lack the energy density
Speaker 3: required to escape their own planet's gravity.
Speaker 2: That is such a tragic image, silent worlds, full of
Speaker 2: thoughts and dreams, but completely voided the technology to act
Speaker 2: on them.
Speaker 3: It is tragic, but it's also in a way empowering
Speaker 3: for us. It forces us to look back at our
Speaker 3: own planet and realize just how incredibly lucky we are.
Speaker 2: We really hit the jackpot, the cosmic lottery.
Speaker 3: We did. We had the right kind of star, the
Speaker 3: right distance from it. We had the liquid water, the
Speaker 3: oxygenic photosynthesis to create buier mass. We had the tectonic
Speaker 3: collision at just the right time to create the basins.
Speaker 3: We had the biological lag to preserve the wood. We
Speaker 3: had the hundreds of millions of years of cooking time,
Speaker 3: and then we evolved at the exact moment the fuel
Speaker 3: was ready to use.
Speaker 2: That is just an unbelievable number of tumblers that had
Speaker 2: to click into place to unlock the door to the universe.
Speaker 3: It is. It suggests that while intelligence might be an
Speaker 3: inevitable product of evolution on many worlds. Technological intelligence might
Speaker 3: be a profoundly rare and accidental product of geology.
Speaker 2: So I want to wrap up with this final thought.
Speaker 2: We started this whole conversation looking for aliens in the sky,
Speaker 2: but we ended up staring at a piece of pole
Speaker 2: here on Earth.
Speaker 3: It really changes your perspective on the resource, doesn't it.
Speaker 3: We rightly demonize fossil fuels today because of the climate crisis.
Speaker 3: They are the villain of our current story, the anthropiscene,
Speaker 3: But this research frames them as something else. It frames
Speaker 3: them as a bridge.
Speaker 2: A bridge we had to cross to get where we
Speaker 2: are now.
Speaker 3: A necessary evil, perhaps a dangerous double edged sword, but
Speaker 3: maybe a necessary one. Without those swampy weird looking for
Speaker 3: us three hundred million years ago, without that dirty, messy,
Speaker 3: polluting phase of our history, we would still be on
Speaker 3: the ground.
Speaker 2: We'd be telling stories around a campfire, looking up and
Speaker 2: wondering what the moon is, instead of having actually walked
Speaker 2: on it.
Speaker 3: Exactly, So, the silence of the universe might not be
Speaker 3: because we are the only ones alive. It might be
Speaker 3: because we are one of the very very few who
Speaker 3: are handed the keys to the library.
Speaker 2: We the ones who won the geological lottery, and the
Speaker 2: terrifying question now is what do we do with the winnings.
Speaker 2: Do we burn the house down with the lottery ticket
Speaker 2: or do we use it to finally graduate to the
Speaker 2: next level of civilization.
Speaker 3: That is the question of our time. It's the challenge
Speaker 3: every technological species, if there are any others, must have faced.
Speaker 2: It's a sobering thought. Next time you see a piece
Speaker 2: of steel, or a skyscraper, or even just turn on
Speaker 2: a light, maybe take a second to remember the millions
Speaker 2: of years of impossible luck that went into it.
Speaker 3: Indeed, keep looking up at the stars, but maybe look
Speaker 3: down at the rocks.
Speaker 2: Once in a while too. Most sad ChIL