Jet engines produce thrust by applying Newton’s third law: throwing a massive amount of air backward creates an equal forward force. Modern turbofans split the work — the giant fan at the front moves about 90% of the air around the combustion core, while only 10% goes through it. That high-bypass design is why today’s airliners are far quieter and more fuel-efficient than the old turbojets of the 1950s. Inside the core, air is compressed to 40 times atmospheric pressure, heated to over 3,000°F, and then expelled through turbine stages that spin the fan. Turbine blades survive those temperatures only because of internal cooling channels that bleed compressed air onto their surfaces.
Where does the fuel live? Not in the fuselage — the wings themselves are sealed to form integral fuel tanks. This “wet wing” design is brilliant because fuel weight counteracts the lift bending the wings upward, reducing structural stress. A 737 carries about 46,000 pounds of fuel; an A380 can carry over 560,000 pounds. Fuel is also an active tool: the flight management computer pumps it between tanks to optimize center of gravity and trim drag. Jet A is refined kerosene with a freezing point below -40°F, and fuel-oil heat exchangers keep it pumpable at cruise altitude while cooling the engine oil.
#2702: How Jet Engines Really Push 100 Tons Through the Air
Where does all that fuel live, and how does a spinning fan produce enough thrust to lift a 747?
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New to the show? Start here#2702: How Jet Engines Really Push 100 Tons Through the Air
Daniel sent us a prompt that I think a lot of people wonder about but never actually ask — how do jet engines produce enough thrust to push a metal tube full of hundreds of people through the air, and where does all the fuel even live on these things? It's one of those questions where the answer is way more interesting than the casual assumption. Most people just accept that planes fly and move on. Daniel, apparently, does not.
He's right to not move on, because the engineering is genuinely spectacular. By the way, DeepSeek V four Pro is powering our script today, so if anything sounds particularly lucid, that's why.
Alright, thrust and fuel storage. Where do you want to start?
Let's start with thrust, because that's the part that seems almost magical. You're sitting at the gate, you watch the engine spin up, and then this hundred-ton aircraft accelerates to a hundred and sixty miles an hour in thirty seconds and lifts off. The question is what's actually pushing it forward. And the answer, stripped down, is Newton's third law. The engine throws a massive amount of air backward, and the equal and opposite reaction pushes the airplane forward. That's thrust.
Right, so it's not the engine pushing against the air like a propeller does. It's a reaction engine. Mass times acceleration out the back equals force forward.
And what's clever about a turbofan engine, which is what powers essentially every commercial airliner today, is how it splits the work. You've got the core, which is where the combustion happens, and then you've got the fan at the front, which is that big spinning disk of blades you see when you look into the engine. The fan is enormous on modern engines. On a GE9X, which is the engine on the Boeing 777X, the fan diameter is a hundred and thirty-four inches. That's eleven feet across. The fan alone moves something like ninety percent of the air that produces thrust.
Wait, ninety percent of the air bypasses the combustion core entirely?
In a high-bypass turbofan, yes. And that's the key insight that made modern aviation efficient. Early turbojet engines, like what you'd find on a 1950s fighter, shoved all the air through the combustion chamber. Very loud, very fuel-hungry, great for going supersonic, terrible for efficiency. A modern high-bypass turbofan might have a bypass ratio of nine to one or even twelve to one, meaning for every pound of air that goes through the core, nine to twelve pounds go around it, accelerated purely by the fan.
The fan is basically a giant ducted propeller, and the core is just there to spin the fan.
That's not a bad way to think about it. The core's primary job is to extract enough energy from burning fuel to drive the turbine that spins the fan. About eighty percent of the thrust on a modern airliner engine comes from the fan, and only about twenty percent from the jet exhaust out the back of the core. It's a fundamental shift from the old turbojet days.
Let's walk through the airflow. Air enters the front, hits the fan. Some goes into the core, most goes around. What happens inside the core?
Alright, the core path. Air enters through the fan, then hits a series of compressor stages. These are alternating rows of rotating blades and stationary vanes. Each stage squeezes the air a little more. By the time the air reaches the combustor, it's been compressed to something like forty times atmospheric pressure on a modern engine. And it's hot, just from compression, maybe a thousand degrees Fahrenheit before you even add fuel.
That's the kind of number that makes you nervous just hearing it.
Then you spray fuel into that compressed, superheated air and ignite it. The temperature in the combustor can hit over three thousand degrees Fahrenheit. The air expands violently and rushes toward the back of the engine. But before it can escape, it passes through the turbine stages. The turbine extracts energy from that rushing gas to spin the compressor and the fan up front. It's a self-sustaining cycle once it's lit. The turbine is what connects the hot section to the cold section via a shaft.
The turbine is both being driven by the exhaust and driving the compressor that makes the exhaust possible. That's an elegant loop.
It really is. And the engineering challenge is that the turbine blades are sitting directly in that three-thousand-degree gas flow, which is hotter than the melting point of the metal they're made from. So turbine blades have internal cooling channels. They actually bleed compressed air from the compressor, route it through tiny holes inside the blades, and it forms a film of cooler air around the blade surface. Without that active cooling, the turbine would melt in seconds.
That's one of those details that separates "we know the principle" from "we actually built one that works for twenty thousand hours without failing." How much thrust are we talking about in real numbers?
A single GE90 engine, which powers the Boeing 777, produces about a hundred and fifteen thousand pounds of thrust at takeoff. That's roughly the equivalent of fifty-five thousand horsepower. A 747 with four engines is putting out something like a quarter of a million pounds of thrust total. But the numbers that really matter for the physics are the air mass flow rate and the exhaust velocity. A GE90 moves about three thousand pounds of air per second at takeoff.
Three thousand pounds of air per second. That's a small house worth of air every second.
It accelerates that air from near standstill to several hundred miles per hour. The thrust is the mass flow rate multiplied by the change in velocity. That's the fundamental thrust equation according to NASA. You can increase thrust by moving more air or by accelerating it more. The turbofan chose "more air, less acceleration" because that's dramatically more fuel-efficient. Kinetic energy scales with velocity squared, so accelerating a huge mass of air a moderate amount uses far less energy than accelerating a small mass of air to supersonic speeds.
Which is why those old turbojets on a 707 were deafening and burned fuel like crazy, and a modern A350 is relatively quiet and sips fuel by comparison.
And there's an interesting tradeoff here. As you go faster, the ram effect starts compressing air at the intake, so the engine becomes more efficient at cruise. A jet engine at thirty-five thousand feet and Mach 0.85 is operating in its sweet spot. The air up there is thin, which reduces drag, but the engine can still grab enough of it because it's moving through the air column so fast.
The engine and the airframe are designed around a very specific altitude and speed envelope. You're not optimizing for takeoff, you're optimizing for cruise, and then making sure takeoff works well enough.
And that brings us to the second part of Daniel's question, which is where the fuel lives. Because to sustain that cruise for twelve or fourteen hours, you need an enormous amount of fuel.
This is the part where most people would guess "in the fuselage somewhere" or "in a big tank behind the cargo hold.
Which is exactly wrong, and for good reason. The fuel is stored primarily in the wings. On most airliners, the wings are the fuel tanks. They're not just structural elements that happen to have tanks inside them. The wing structure itself forms the tank. The skin of the wing, the spars, the ribs, they're all sealed to create a cavity that holds fuel. These are called integral fuel tanks or wet wings.
When you look out the window and see the wing, you're looking at a giant fuel bladder.
And it's brilliant engineering when you think about it. The wings are the widest part of the airplane, so that's where you have the most volume. But more importantly, fuel is heavy. On a long-haul flight, fuel can be forty percent or more of the aircraft's total takeoff weight. Putting that weight in the wings means the lift is generated right where the mass is, which reduces the bending stress on the wing root. If you put all that fuel in the fuselage, the wings would have to be much stronger and heavier to support the fuselage weight in flight.
The fuel in the wings is actually reducing structural load. It's counterbalancing the lift force.
The lift wants to bend the wings upward. The fuel weight in the wings counteracts that bending moment. On the ground, a fully fueled wing actually droops slightly. In flight, it flexes up to its design shape. Engineers call this load alleviation, and it's a major reason the wet wing design is universal.
How much fuel are we talking? Give me numbers for a couple of common aircraft.
A Boeing 737-800 carries about six thousand eight hundred seventy-five gallons of Jet A fuel, which is roughly forty-six thousand pounds. That's about twenty-one metric tons. An Airbus A380, the double-decker, can carry up to about eighty-five thousand gallons in its wings and center tank, which is over five hundred sixty thousand pounds of fuel. That's two hundred fifty metric tons. The fuel alone on an A380 weighs more than the entire maximum takeoff weight of a 737.
That's staggering. And it's all just sitting in the wings and a center tank between the wings?
Most of it is in the wings. The center tank is in the fuselage, between the wings, basically under the passenger cabin floor. It's an additional tank that sits in the wing box area. On a 737, the center tank holds about four thousand seven hundred liters. On a 777, the center tank can hold over a hundred thousand pounds of fuel. Some long-range variants also have auxiliary tanks in the aft cargo hold, but that's less common. And then some aircraft, like the 747, have a horizontal stabilizer fuel tank in the tail for trim purposes. You pump fuel back there during cruise to optimize the center of gravity and reduce trim drag.
So moving fuel around is an active aerodynamic tool, not just a storage problem.
Yes, and this is where it gets really elegant. Modern airliners have a fuel management system that actively pumps fuel between tanks during flight. As you burn fuel, the center of gravity shifts. The flight management computer monitors this and moves fuel to keep the aircraft trimmed optimally. Even on a simple level, you always burn from the center tank first, then the wing tanks, because keeping fuel in the wings as long as possible maintains that load alleviation benefit.
The sequence matters. Center tank drains first, then the wings. And what about the actual fuel itself? Jet A, you said. What is it?
Jet A is essentially a highly refined kerosene. It's very similar to diesel fuel, actually. It has a higher flash point than gasoline, which makes it safer to handle. It doesn't ignite as easily at ambient temperatures. It also has a very low freezing point, around negative forty degrees Fahrenheit for Jet A, and negative fifty-three for Jet A-1, which is the international standard. At cruise altitude, the outside air temperature can be negative sixty or colder. The fuel in the wings is sitting right against the skin, so it gets cold-soaked. Jet fuel needs to remain pumpable at those temperatures.
I assume there's heating involved.
There's a fuel-oil heat exchanger. The engine oil gets hot, obviously, and the fuel gets cold. You run them through a heat exchanger, the oil heats the fuel, the fuel cools the oil. It's a neat bit of thermal integration. Also, on some aircraft, fuel is circulated through integrated drive generator cooling systems before being burned. The fuel is a heat sink for the entire aircraft.
Fuel is structural load alleviation, trim management, and thermal management, all before you even burn it. It's not just a tank of liquid.
And the plumbing that makes all this work is extensive. A 777 has something like sixty miles of wiring and a fuel system with dozens of pumps, valves, sensors, and a central computer. When the pilots manage fuel, they're not just watching a gauge. The system is actively balancing, transferring, and cross-feeding between tanks to maintain optimal conditions.
Let's go back to the combustion part for a second, because I want to understand what happens inside the combustor in more detail. You said three thousand degrees. How do you get complete combustion in the milliseconds the air is passing through?
This is a great question. The air is moving through the combustor at something like a hundred to two hundred feet per second. That's faster than a hurricane wind. You have to inject fuel, mix it, ignite it, and complete combustion in a space about the size of a household trash can, and you need to do it without the flame blowing out. The solution is something called a flame holder or a swirl-stabilized combustor. The combustor is designed with a region of recirculating flow, a low-velocity zone where the flame can anchor itself. Fresh fuel-air mixture continuously feeds into this zone, ignites, and the hot products then mix with the remaining air downstream. Only about twenty percent of the air entering the combustor is used for actual combustion. The rest is used for cooling the combustor walls and diluting the hot gases before they hit the turbine.
Because if you sent three-thousand-degree gas directly into the turbine, even with blade cooling, it wouldn't survive.
The dilution air brings the temperature down to something the turbine can handle, which on modern engines is still around two thousand five hundred degrees Fahrenheit at the turbine inlet, but with the blade cooling and thermal barrier coatings, that's manageable. The thermal barrier coatings are ceramic layers applied to the turbine blades. They can reduce the metal temperature by a couple hundred degrees.
The combustor itself has to be an extraordinary piece of thermal engineering. What's it made of?
Nickel-based superalloys, typically. Materials like Inconel. They retain strength at temperatures where steel would be glowing and sagging. And the combustor liner has thousands of tiny cooling holes. It's the same film cooling concept as the turbine blades. A thin layer of cooler air blankets the metal surface.
This entire assembly, the fan, compressor, combustor, turbine, all spinning at what speed?
The high-pressure spool on a large turbofan might spin at around ten thousand to twelve thousand RPM. The fan and low-pressure turbine are on a separate shaft and spin slower, maybe two thousand five hundred to four thousand RPM on a large engine. The two shafts are concentric, one spinning inside the other. That's why it's called a two-spool engine. The GE90 actually has a three-spool design on some variants, with an intermediate-pressure compressor and turbine on a third shaft.
Three concentric shafts. The mechanical precision required for that, at those temperatures and rotational speeds, with blades that are essentially single-crystal metal structures grown in a lab.
Single-crystal turbine blades are worth mentioning. Conventional metal has grain boundaries, which are weak points at high temperatures. By casting the blade as a single continuous crystal with no internal grain boundaries, you eliminate those weak points. It's metallurgy that borders on alchemy. These blades are grown in vacuum furnaces using directional solidification techniques. Each blade can cost thousands of dollars.
There are dozens of them per engine.
A high-pressure turbine stage might have sixty or eighty blades. And they're all precisely shaped airfoils with internal cooling passages that are cast into the blade, not machined afterward. The casting process creates the cooling channels using ceramic cores that are leached out afterward.
Let's connect this back to the thrust question. All of this engineering serves one purpose: accelerate air backward. How fast is the exhaust coming out at takeoff?
For a high-bypass turbofan at takeoff, the exhaust velocity from the fan is maybe six hundred to eight hundred feet per second. The core exhaust is faster, maybe twelve hundred to fifteen hundred feet per second. But remember, most of the mass is in the fan stream. The average exhaust velocity weighted by mass flow is probably around seven or eight hundred feet per second. That's about five hundred miles per hour. The aircraft itself is only moving at a hundred and sixty miles per hour at rotation. So the engine is throwing air backward at three times the speed the plane is moving forward.
That's the momentum exchange that Newton demands. And at cruise?
At cruise, the aircraft is moving at about five hundred fifty miles per hour true airspeed. The engine is still accelerating air backward relative to itself, but now the intake air is already moving at the aircraft's speed relative to the outside world. The net acceleration imparted to the air is actually less at cruise than at takeoff, but the mass flow is enormous because you're ramming air into the intake. The thrust produced at cruise is much lower than at takeoff, maybe twenty to twenty-five percent of maximum. You only need enough thrust to overcome drag, which at high altitude is significantly reduced.
The fuel consumption reflects that. You burn a huge amount during takeoff and climb, then it settles into a much lower rate at cruise.
A 747 burns about five thousand pounds of fuel per hour per engine at cruise, roughly. During takeoff and initial climb, it's burning significantly more. The first few thousand feet of altitude are incredibly fuel-intensive. That's why long-haul flights are more fuel-efficient per passenger-mile than short hops. The climb penalty gets amortized over a longer cruise.
Which brings us back to where all that fuel goes. You mentioned the center tank and wing tanks. How is the fuel actually contained? Is there a bladder, or is it literally just the wing structure sealed up?
It's the wing structure sealed up. The joints between the skin panels, ribs, and spars are sealed with a special fuel-resistant sealant. The rivets and fasteners are installed wet with sealant. The entire structure is essentially a tank. There are access panels for inspection, but they're sealed with gaskets. It's not a bladder inside the wing. The fuel is in direct contact with the aluminum or composite structure.
If you opened a wing panel on a fueled aircraft, fuel would pour out.
Yes, and maintenance crews do exactly this when they need to inspect the inside of a tank. They defuel the aircraft, purge the tank with inert gas, and then enter through access hatches. It's confined space entry, highly regulated. Fuel tank explosions have happened in the past, most famously TWA Flight 800 in 1996, which was caused by a center fuel tank explosion. Since then, fuel tank inerting systems have become mandatory. They pump nitrogen-enriched air into the ullage space above the fuel to reduce the oxygen concentration below the level that can support combustion.
The ullage being the empty space above the liquid fuel.
As you burn fuel, that space fills with air. If the fuel-air mixture in that space is within the flammable range and there's an ignition source, you have a bomb. The inerting system prevents that by replacing the air with nitrogen.
That's now standard on all commercial aircraft?
It's been mandatory for new aircraft since around 2008, and retrofits have been required on existing fleets. The FAA issued the rule after years of NTSB recommendations following TWA 800.
Let's talk about the fuel system's journey from tank to combustor. How does fuel get from the wing to the engine at the rate required?
There are boost pumps in each tank, electrically driven, that supply fuel to the engine-driven pumps on each engine. The engine-driven pump is a high-pressure gear pump that can deliver fuel at pressures up to fifteen hundred PSI or more. The fuel then passes through the fuel-oil heat exchanger, through a filter, and then to the fuel control unit, which meters the precise amount of fuel required based on throttle position, altitude, temperature, and other parameters. The fuel is then sprayed into the combustor through fuel nozzles that atomize it into a fine mist for rapid mixing and combustion.
Fifteen hundred PSI. That's industrial hydraulic pressure.
The metering has to be incredibly precise. At idle, the fuel flow might be a few hundred pounds per hour. At takeoff, it's tens of thousands. The fuel control system has to handle a hundred-to-one turndown ratio while maintaining precise air-fuel ratio control. Too rich and you get smoke, wasted fuel, and potentially turbine damage. Too lean and the flame blows out.
Are we still using hydromechanical fuel controls, or is it all digital now?
It's been full authority digital engine control, FADEC, for decades now. The pilot moves the thrust lever, which sends an electrical signal to the engine computer. The computer interprets that as a thrust demand and adjusts fuel flow, variable stator vanes, bleed valves, and other effectors to deliver that thrust efficiently and safely. The pilot is not directly controlling the engine. The computer is. The thrust lever is basically a request knob.
Which means the computer can also protect the engine from the pilot. If the pilot firewalls the throttles, the FADEC will spool the engines up as fast as possible without exceeding temperature or speed limits.
Over-temp protection, over-speed protection, surge margin protection. The FADEC is constantly monitoring hundreds of parameters and keeping the engine within its operating envelope. It's one of the unsung heroes of modern aviation safety.
We've got the physics of thrust, the engineering of the engine core, and the storage and management of fuel. Is there anything about the thermodynamics that's worth unpacking? The efficiency question?
The Brayton cycle is the thermodynamic cycle for gas turbine engines. It's compression, constant-pressure heat addition, expansion. The efficiency of the cycle fundamentally depends on the pressure ratio. Higher compression ratio means higher efficiency. Early jet engines had pressure ratios of maybe five to one. The GE9X has an overall pressure ratio of sixty to one. That's a sixty-fold increase in pressure from intake to combustor. That's why modern engines are dramatically more efficient than their predecessors.
The limiting factor is materials and cooling, as we've discussed. You can't just keep increasing the pressure ratio without the turbine inlet temperature becoming unmanageable.
Every increase in pressure ratio drives up the compressor discharge temperature, which means the combustor starts hotter, which means the turbine sees hotter gas. The entire development history of jet engines is a story of better materials and better cooling allowing higher pressure ratios and higher turbine inlet temperatures. The GE9X operates at a turbine inlet temperature that's hundreds of degrees hotter than engines from the 1990s, while being more reliable and lasting longer between overhauls.
Because the single-crystal blades, the thermal barrier coatings, the film cooling, the FADEC protecting the engine from excursions. It's all connected.
There's another fascinating aspect. Ceramic matrix composites are starting to appear in the hot section. These are ceramic fibers embedded in a ceramic matrix. They're lighter than nickel alloys and can withstand even higher temperatures without cooling. The LEAP engine from CFM International uses CMC shrouds in the turbine. The GE9X uses them for combustor liners and turbine shrouds. That's the next frontier.
We're gradually replacing metal with ceramic in the hottest parts.
That's going to enable pressure ratios of maybe seventy or eighty to one, and bypass ratios of fifteen to one or higher. The open rotor or unducted fan designs that are being explored would essentially eliminate the nacelle and have the fan spinning in the open air, like a propeller but with many highly swept blades. That gets you to bypass ratios of thirty to one or more, which would be another step change in efficiency.
Brings noise and blade-off containment challenges.
If a fan blade lets go inside a nacelle, the nacelle contains it. If a fan blade lets go on an open rotor, it's uncontained. That's a certification challenge that hasn't been fully solved yet.
Let's circle back to fuel storage one more time, because I want to talk about the refueling process. How fast can you pump fuel into these tanks?
A wide-body aircraft can be refueled at something like a thousand gallons per minute through two hoses. So an A380 taking on eighty-five thousand gallons could theoretically be fueled in under an hour, though in practice it takes longer due to the need to balance tanks and verify quantities. The refueling is done under pressure through a single-point refueling panel, usually under the wing or in the belly, where the ground crew connects the hose and dials in the desired fuel load. The system automatically distributes fuel to the correct tanks in the correct sequence.
The fuel itself, where does it come from at the airport?
There's a whole underground fuel farm and hydrant system at major airports. Fuel is delivered by pipeline or tanker truck to large storage tanks at the airport perimeter. From there, it's pumped through underground pipes to hydrant pits at each gate. A fueling truck or cart connects to the hydrant and pumps fuel up into the aircraft. It's a closed system that minimizes contamination risk. The fuel is filtered multiple times and tested for water and particulate contamination before it goes into the aircraft.
Water in jet fuel is a big deal, right? Because at altitude it can freeze and block fuel lines.
Water is the enemy. Jet fuel always has some dissolved water in it, and as the fuel cools, that water comes out of solution and can form ice crystals. Fuel filters have water-absorbing elements, and the fuel system has heaters to melt any ice that forms. But water management is a constant concern, especially on long polar routes where fuel temperatures can drop to negative forty or lower for extended periods.
The fuel system is dealing with thermal management, water contamination, vapor flammability, structural integration, and precise metering. It's basically a chemical processing plant wrapped inside an airplane wing.
It's so reliable that we never think about it. You board a flight, you might wonder about the engines, but you never wonder whether the fuel will get from the tank to the combustor. It just does, flight after flight, for decades.
There's something to be said for the sheer mundanity of the miracle. You're sitting in a chair at thirty-five thousand feet, moving at five hundred fifty miles per hour, powered by a machine that swallows three thousand pounds of air per second and burns fuel at a rate that would drain a swimming pool in minutes, and the most stressful part is whether the Wi-Fi works.
That's the triumph of the engineering. Not that it works, but that it works so reliably that it's boring. The failure rate of modern turbofan engines is something like one shutdown per hundred thousand flight hours. That means an engine might run for ten years of continuous operation before experiencing an in-flight shutdown. That's an extraordinary level of reliability for a machine operating at the edge of material science.
One shutdown per hundred thousand hours. That's a number that should impress anyone who understands what's happening inside that engine.
It's getting better. The ETOPS certifications, which allow twin-engine aircraft to fly long over-water routes far from diversion airports, now extend to three hundred thirty minutes for some aircraft. That's five and a half hours on a single engine. The A350 is certified for ETOPS three hundred seventy. That's a vote of confidence in engine reliability that would have been unthinkable in the three-engine and four-engine era.
Because the whole premise of a four-engine 747 was redundancy. If you lose one, you still have three. Now we're saying, we're so confident in these two engines that we'll let you fly five hours over the Pacific on one.
That's backed by decades of data. The high-bypass turbofan has proven itself to be an extraordinarily robust machine. The GE90 fleet has accumulated over a hundred million flight hours. The CFM56, which powers the 737, has over a billion flight hours. These are numbers that allow statistical confidence in reliability predictions.
Alright, I think we've covered the thrust physics, the engine internals, the fuel storage, the fuel system, and the reliability. Daniel wanted to know how jet engines produce enough thrust and where the fuel lives. I think we've given him the deep dive.
The core insight, if I had to distill it, is that a jet engine is a momentum exchange device. It takes a huge mass of air, accelerates it backward, and the reaction force pushes the airplane forward. And the fuel lives in the wings because that's where the mass is structurally beneficial. Everything else is detail, but what detail it is.
The detail is where the awe lives. The single-crystal turbine blades, the sixty-to-one compression ratios, the wet wings sealed with miles of sealant, the nitrogen inerting systems, the FADEC computers interpreting a pilot's thrust request into a symphony of fuel metering and variable geometry. It's one of humanity's greatest engineering achievements, and it's hiding in plain sight on every runway.
And now, Hilbert's daily fun fact.
Actually, I'm taking this one. And now, Hilbert's daily fun fact.
Hilbert: In eighteen eighty-five, a surveying expedition in Australia's Simpson Desert mapped and named "Lake Caroline," a substantial body of water they claimed to have sighted from a ridge. Subsequent expeditions spent decades searching for it before cartographers officially declared it a phantom lake, likely a mirage caused by the desert's intense heat shimmer reflecting the sky.
Hilbert: In eighteen eighty-five, a surveying expedition in Australia's Simpson Desert mapped and named "Lake Caroline," a substantial body of water they claimed to have sighted from a ridge. Subsequent expeditions spent decades searching for it before cartographers officially declared it a phantom lake, likely a mirage caused by the desert's intense heat shimmer reflecting the sky.
A lake that was never there.
Cartography by wishful thinking. So we've unpacked a lot today. The one thought I'll leave with is this: the jet engine is often described as a solved problem, but the pace of improvement hasn't stopped. Ceramic matrix composites, geared turbofans, open rotor designs, even hybrid-electric propulsion concepts for smaller aircraft. There's still plenty of frontier left. The basic Brayton cycle isn't going anywhere, but the materials and architectures wrapping around it are still evolving fast.
The fuel question is evolving too. Sustainable aviation fuels, hydrogen combustion, even direct electrification for short hops. The next thirty years of aviation propulsion might look very different from the last thirty.
Thanks to our producer Hilbert Flumingtop for keeping us running. This has been My Weird Prompts. You can find us at myweirdprompts.com and on Spotify. We'll be back with another one soon.
This episode was generated with AI assistance. Hosts Herman and Corn are AI personalities.