Helium is one of those weird products of the technological age; special and vanishingly rare, discovered by spectral lines around our own star, its mining & refining should be a thing of wonder but instead we mostly know it for balloons and hilarious chipmunk voices. After all, sufficiently advanced technology is indistinguishable from magic, and sufficiently well-used magic is boring and a party trick for children. 

Helium is vastly more rare than gold.

That’s quite annoying for something as useful as it is, because it not only floats blimps and balloons, but also leak-checks medical implants, supercools magnets in MRI machines (that could save your life!), assists manufacturing in semiconductor fabs, lets deep-sea divers reach the ocean floor and pressurizes propellant tanks in space rockets… and this list is nowhere near complete. Frankly, it deserves our respect for MRI machines alone. 

Its rarity is also something of a head-scratcher, because helium is the second most common element in the universe after hydrogen and is a primary fusion product in most stars. But not on Earth!

It’s rarity on Earth (about five parts per million in our atmosphere) is mainly due to the other thing that everyone knows about helium, which is that it’s really, really light. The low atomic weight of the stuff makes its velocity when excited by solar radiation so incredibly high that it’s constantly being bled out of our atmosphere, accelerated to escape velocity by a sunny day. Unlike the gas giants of the solar system (Jupiter, Saturn and -hurr- Uranus) our gravity just isn’t strong enough to hold the lightest elements, and unlike hydrogen you can’t make it by shoving electrodes into water.

And because of all of this it was completely unknown to science up until 1868, when French astronomer Pierre Janssen used a total eclipse to focus his spectroscope at the sun’s chromosphere and found something strange: A yellow line that corresponded to no element known to science. A couple of months later this was substantiated by Englishman Norman Lockyer, and the new element was named helium, after the Greek word Helios. The Sun.

And for quite a long time that was that, because nobody on Earth could get their hands on this mystery of the stars. There were no samples to test, no collections to analyse, until Scottish chemist William Ramsay managed to acquire it by treating the mineral cleveite with acids. In essence it was obtained by obtained by dissolving rocks where radioactive decay had trapped alpha particles (helium ions). Helium is, after all, a nuclear product, produced through either the radioactive decay of a heavy element or the fusion of the only lighter one; hydrogen!

Great, helium on-demand! Except in such tiny quantities that no use could possibly be found for it, until…

…Until an exploratory oil well in Kansas produced, in 1903, a geyser of natural gas with something very odd about it. 

It refused to burn.

1: The Space Connection.

For many decades helium has been an invisible hand behind some of the most dramatic technological creations anywhere: Orbital space rockets. These are creations that seared an image of incandescence into the eyes and imaginations of children everywhere, from the Space Shuttle to the ubiquitous Falcon 9. It’s the pioneer dream of a life off-world, led by a wagon train riding a pillar of its own destruction. -And behind this; helium.

For a rocket to function, fuel and oxidiser must be pressurised and pumped at tremendous rates into a combustion chamber where it is ignited and allowed to expand through a convergent-divergent duct, accelerating to the point where it can lift and move a vast rocket. It’s an act of techno-machismo without parallel, a vast thumbed-nose at nature, offending with sheer velocity. -But to work at all, you need to pressurise the propellant.

For many decades helium was the natural choice of pressurizing medium: It’s stable, unreactive, remains gaseous across a wide temperature range and can sustain high pressures across large volumes with very little weight. Stores of pressurised helium were for many years vented into fuel and oxidiser tanks, pushing out the stuff that goes boom. It’s not the only way to do this, but for something as weight-sensitive as a space rocket it’s a pretty good solution. 

But it uses a bucketload of Helium! The Falcon 9, the world’s most common launch vehicle, uses about one hundred thousand dollars of Helium per launch, which is hardly ideal. It might be a rounding error in the economics of orbital access today, but if the industry is going to keep reducing costs and making space access cheaper, that can’t continue. -That’s why the very latest launchers such as Ariane 6, Blue Origin’s New Glenn and SpaceX’s glamorous monster, Starship, all use something called autogenous pressurization instead. In autogenous pressurization, the tank pressurization gas is self-generated by the vapourisation of some of the rocket’s own cryogenic propellant. That, at least, helps to relieve you of the need for quite so much helium.

The space sector is a minnow in the helium ocean and, for all its drama, only uses a tiny fraction of the total global consumption of the gas. About half of it is used between medical cryogenics and semiconductor electronic manufacture. Another third is split between welding, leak detection, scientific use and, of course, in balloons. Space travel really is a tiny proportion of the six-and-a-half-billion cubic feet per year helium industry. 

But the fact that something so apparently big as space launch is actually quite small, and the fact that even this industry wants to use less of it points to two big inconvenient questions.

Firstly, how did helium go from a scientific curiosity to a massive process industry?

And secondly, what’s constraining the supply?

Let’s return to that un-ignitable gas geyser in Kansas…

2: Mining for space gas.

An exploratory well drilled in May 1903 tapped into a high-pressure reservoir at a mere 560 feet of depth, which then geyser-ed out of the well. During assessment of this potential bounty, the derogatory ‘wind gas’ well was found to be almost impossible to light. Not ideal for a natural gas source, as I’m sure you’d agree. 

At the time, before the advent of surge preventers, lighting natural gas exhalations was a common practice during drilling, and a big gas well could be quite a tourist draw, with a pillar of flame spearing the heavens day & night for months on end. So it was unfortunate that, in an evening ceremony, the mayor of Dexter finished his speech, requested a bay of burning hay to be flung into the well and watched as it was dismissively blown out. Another attempt was made, and then another, with the same result. Eventually the crowd dispersed.

Two years later, the oilmen long-since departed, scientific analysis revealed why: The wind gas well was mostly inert nitrogen, with a certain amount of methane gas, and almost 2% helium. No wonder the bloody thing never caught fire!

Helios, the god of the sun, had been found in Kansas!

Over time it emerged that this was not a freak event (though the helium percentage, at almost 2%, was unusually high). If a geological trap of the kind that sequesters methane occurs in proximity to the kind of long, subtle nuclear decay process that creates helium, then it can ooze its way through rock and find itself trapped within natural gas.

How convenient! The source of our energy, our plastics and chemical industry is now also co-located not only with natural gas but also with the magic stuff that chills our MRI machines and floats blimps. The sun gas, trapped underground!

This realization would be the start of the industrial mass-exploitation of helium: Why go to the sun for it, or suck traces from radioactive decay, if you can simply drill for it instead?

But of course, finding it isn’t enough. Any fool can drill, but it takes real wisdom to refine it, and how do you refine & purify an inert gas, mixed in with lots of other gas?

You must make it cold. Very cold!

3: Mapping your insides.

I remember the first time I lay down inside a magnetic resonance imaging machine. It was an early morning in Waterford and I’d arrived at the Whitfield Centre after a dark-hours drive across Ireland to get my back scanned, due to the impressive amount of pain it had been causing me. Slipped disc? Spinal damage? Who knows! I certainly didn’t, which is why I needed a machine to look inside me. 

You lie back and, staring straight upwards get pushed on a travelling dolly into a smooth white-walled tunnel. It’s tight in there, and claustrophobic. God only knows what they do for really fat people; maybe wedge them in like a cork in a bottle? It’s not comfy, that’s for sure. 

Then the machine starts, and it's really something else. The walls don’t so much as quiver, but a colossal whining, grinding sound kicks-off, muffled through the headphones you’re asked to wear so that you’re not deafened. Superconducting magnets, chilled to within a few degrees of absolute zero, are energised and an invisible magnetic field of vast strength threads its way through you. It’s enough, were it to pick up a metal trolly, to crush it into a twisted mess, but you can’t feel it. The water molecules inside you do though, as the hydrogen protons inside the nuclei of your very body align themselves to the magnetic field. Radio waves are then pulsed through you, knocking the subatomic missionaries out of position. When they flick back into alignment they release their own radio wave echo, and by studying this you can work out the proportion of water in different tissues, and build a map of a person’s insides. 

It’s magic, basically, Noisy, claustrophobic magic with a terrifying magnetic field.

Naturally, I went to sleep inside it. Don’t judge! It was early, I’d had a hard week and I’d been driving there at crazy hours. It passed the time anyway. 

But what, you may be thinking, has any of this got to do with helium? I shall tell you!

Helium is crucial in MRI machines because liquid helium supercools the electromagnet coils, turning them into superconductors. A superconducting coil can pass a big electrical current though an endless loop without any electrical resistance at all. This generates a huge magnetic field, and it does so in a way that doesn’t require masses of power, because the superconductor has no electrical resistance: The electrons just keep looping, around and around, forever. Conveniently, this lets a big scary machine with calming paintwork and moulded-smooth surfaces look inside a human being. If they’re not too fat, anyway.

And the way it does this is by exploiting a unique characteristic of helium. As well as being super-light and pleasingly inert, it’s also got a hilariously low boiling point: Just over four degrees above absolute zero, which is lower than anything else. 

Keep helium a liquid and you can chill something down to almost the lowest temperature it’s possible for anything to be… and look inside my spine while you do it.

And this is doubly useful, for helium’s low, low boiling point is also the very thing that allows us to refine it in the first place. Very cool!

4: Freeze it and make it pure!

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Dogs are more sensible. They don't get up from their nap, stretch with their distinctive “naauuurrghaaar!” sound and suddenly decide to jump into ice baths with lots of other dogs, or haul themselves over big walls, or crawl under wires buzzing with high voltage electricity. So why do us silly apes seem to enjoy it so much?

-A disclaimer: Actually I don't enjoy being repeatedly shocked by something designed to hold cattle. Everything else today was great craic, but not that bit.

The event was the bi-annual Hell & Back run on the drizzly Kilruddery Estate in County Wicklow, Ireland. I've done it a bunch of times, and typically a few thousand other enthusiasts join in, at all fitness levels. Some psychopaths run fast the entire way, others go slowly and I'm somewhere in-between. You finish stinking, with bloody knees & elbows, caked in mud and absolutely exhausted.

You can see why I go back most years… but why?

We are a species torn from nature by the tyranny of a big brain, but while we enjoy cruising in air conditioned comfort, something in our hind-brain yearns to harry prey through biting bracken.

And no spreadsheet will ever feel like hunting or gathering.

So something in our unconscious is uneasy: We sit around the fireside swapping stories, metaphorically or otherwise. Maybe the fire is a big TV and maybe the stories are swapped through a glowing rectangle by the Pocket Demon, but that's what we're doing… and something inside us feels that we haven't earned it!

Which is why we must take to the hills and exhaust ourselves.

This hunter-gatherer instinct is a perfect counter to the preaching of those whose utopia looks an awful lot like some sort of green techno-communism: Benevolent overseers placating populations with universal subsidies paid for by the savants and AIs that run the place. Everything else, of course, is reduced to a declinist degrowth cottage fantasy, where communal clothes-washing by hand is our sole outlet for gossip & community. Anything so unvirtuous as a washing machine would offend the polar bears, and progress is imperialist. Can't have that now, can we.

The inner caveman roars and beats back the bracken.

The same instinct that makes so many of us don boxing gloves, chase pavements, cross the wild places and tackle each other on muddy fields… it simply couldn't cope with equity and comfort. Our caveman brains need to seek and hunt. We need to work ourselves to find the fruits of the spring and the big game of the autumn. Our explorers need to know that there are other valleys to explore. Our warriors need to know they are needed.

Do you really want the warriors kicking their heels with nothing to do? Didn't think so.

A world without work is a utopia for children. Everything glorious in our society stems from the lashing-out of ancient instincts as we struggle to earn our place at the fireside. If we can build cathedrals or launch rockets to Mars, we do so. For the rest of us, there is always the rugby pitch and the muddy hills.

Beware those who champion equity above all, and who rail against progress. They are not your friends, and would cast you out of the hunt.

And you need the hunt…

Caveman must run!

The Harvard octopus wasn't alive and had a brain that flowed with vapour, not electrons. It had no cables, no motors, no batteries and no clever little CPU. It was a thing of squishy limbs and chemical power alone, and that was enough.

Because the creature's brain was pneumatic!

Octobot was a pretty simple affair and could only power itself for eight minutes at a time through a hydrogen peroxide reservoir and a platinum catalyst, but it was enough to prove the idea that logic doesn't need to be slaved to silicon.

The ersatz synapses firing in that mockery of life weren't organic and they weren't electrical either, but an expression of simple physics.

…Not so different from us, then. We are also an expression of physics, but ten billion times more complex, and not pneumatic or hydraulic.

This is fluidic logic. You can make computers this way.

And weird robot octopi are only one application of fluidic logic. It goes far, far further than that, and gets weird.

Want to find out about it?

1: Stop The Plane!

Beneath our world of silicon sorcery lives a much older one, hidden from view but still alive in those places where air hisses and steam takes orders from mortal men.

After all, we controlled very complex machinery long before the invention of the electronic computer. We used mechanisms, hydraulics and compressed air. In many places we still do.

Electronic computers are undoubtedly powerful; fast, flexible, precise, able to calculate a million things at once and be reprogrammed at will. But we didn't always need them, and this begs a few questions: 

Can you make a computer that runs on fluids & mechanisms instead of air? Is there any reason I'd do that?

And can I make a Commodore 64 that computes with pneumatics, and then play Elite on it?

All good questions, but a lot of it starts with how can I do basic logic processing with just air!? Fortunately, that's a question with a lot of very good answers, to which we need to look no further than a transistor.

The transistor is the workhorse of modern micro-electronics. Billions of them are etched into every silicon chip in an act of precision miniaturisation that flirts with actual magic. But for all that mystical techno-sorcery, the actual function of a transistor is simplicity itself.

A transistor is part switch, part amplifier. A small current enters, which opens a ‘gate’ for a much larger current to pass through the component. That's it. Multiply by billions and shrink to the nanometer scale and you're sorted.

OK. Great. How do I replicate that with fluids?

Using traditional valves it's easy enough: A small signal flow can move a sprung valve body to one side, allowing a thru-hole to align with a much larger, higher pressure flow that then roars into being. Instant flow amplification! A transistor. 

But what if we want to follow the Octobot's example and run fluidic logic without any moving parts at all? There is a way, and to reveal it we shall look at the DC-10 airliner.

A long time before Octobot there was the DC-10, the archaic three-engined poster boy from the 1970s. This was notable not just for having three engines, but also for being the first commercial aircraft to use fluidic logic, which it used to drive the thrust reverser.

Basically a relatively small compressed air input (the control) would deflect a much higher volume flow into one or more actuation channels.

This can be done in multiple ways: See the example of the bistable Coanda effect amplifier shown below. In this, without a control signal the fluid just blasts straight into a baffle, deflecting it into the vents. Add a control signal in either direction and the main flow is directed into one of two outputs, to actuate whatever equipment you desire.

What's interesting about this example is it's bistable: A single control signal persistently deflects the output even once the control is turned off, as the jet hugs the wall through the Coanda effect and sets up recirculating vortices over the baffle that keep it there. Another control jet is required to deflect it once set, or both at once to reset the stream.

And just like that we've created a transistor and primitive memory storage with nothing more than flow and clever geometry.

That's fine for actuating a thrust reverser or industrial machinery, but there's a whole bundle of logical functions in a computer, so transistors alone are insufficient. Can we perform other logical functions?

Can fluids think?

2: Soft, sensitive robots.

We all know about robots these days, but what comes to your mind when thinking about them? If like me you’re of a manufacturing persuasion, hiding crustacean-like in the nooks and crannies of the industrial reef, then a ‘robot’ means an industrial arm, moving, grasping and placing with scary speed and impossible precision. To the more excitable sort of technophile a ‘robot’ might mean a sleek bipedal tech-demonstrator doing backflips or serving cocktails for photo-ops. Or for those of a more Black-Mirror tendency it might be the iconic figure of Boston Dynamic’s quadrupedal robot ‘dog’, an eyeless yellow oddball that has an uncomfortable hint of Bloodhound about it: It’s all too easy to imagine it chasing you through woodland, stabbing a red targeting laser through writhing ferns. 

What you’re unlikely to picture when thinking of a ‘robot’ is something… soft. But why not?

Soft robotics is a new field, borne of the realization that robots, while very useful on their own, could be even more useful if they were collaborative. -And collaboration with humans means not breaking their bones, jabbing them with implements or getting confused by our waffly lack of precision.

A soft robot is one where sinews of cable and muscles of motors are swapped-out and replaced by something squishier and friendlier for us to work with. It might be a collaborative tool, a rehabilitative aid or a questing searcher through the rubble. It’s designed to yield slightly to the chaos of the world, like your hand as it grips or a root working around objects. 

And when one of these objects is a human hand, with its fragile, snappable bones, a soft robot could become a wearable rehabilitative tool for stroke victims. It could be a force amplifier, increasing their grip strength without forcing them into motions outside the normal range of their joints: A soft exoskeleton hydraulically or pneumatically powered through squishy actuator ‘muscles’, helping those injured by trauma come to terms with their body again. 

Sounds nice. Where does fluid logic fit in?

Both micro-fluidics and soft robotics are fields mostly working in isolation. This is a shame, because they are natural bedfellows. 

A micro-fluidic amplifier, if sufficiently miniaturised in a pliable substrate, is effectively a flow sensor, and if its input is the pressure induced by a stroke victim grasping their hands, and the output is an amplification of this force, then a clever prosthesis controlled by micro-fluidics could wrap around a person’s limbs or fingers and amplify their efforts. Useful for someone recovering from serious physical trauma. 

The pressure would have to come from somewhere of course, and you could always use a motor, but a clever person might see something more elegant: Perhaps an inflated bladder, pressurised by the casual movements of a person’s hips or core in any of the hundreds of unconscious movements we make every minute? It could harvest this unconscious corrective load and transmit it to the hand, arms or legs, to charge the fluidic sensors, amplifiers and logic gates that an injured person needs to move again. 

Help, from a friendly soft robot.

And the funny thing about this would be that the logic, the ‘brains’ of the operation would be distributed: Sensors and logic circuits in the fingers, arms and joints, near to the action. The user would become a hybrid, like the alien octopus with eight little brains in its arms. Part human, part hydraulic, a creature of pressure that thinks with fluid. 

Or why not use soft robotics to make a ‘tapeworm’ for pipe inspection? A ring-shaped hollow softie that undulates its way through the dark places, checking out the flow, feeling the texture of the walls and listening to the sounds of the underground. You could control its undulations with fluidic logic, powered by an electric pump… or if you're clever, even the flow itself.

Give the worm a ring mouth and it could sample liquid or gas and create pressure differences that could power it using a ram-effect or ringed venturi sections, tapping the flow just enough for propulsion. Do this with a clever soft robot, that twists and gropes its way around obstructions, and you'll have created an organic-looking inspection worm with infinite range: Feeling the pressure and thinking with flow…

The Chernobyl Wyrm.

Or perhaps I’m being too poetic. I mean, how do these flow logic gates work anyway?

Let’s get into the fine technical stuff, shall we!

3: Gates to success.

We've established that you can supplement an electrical binary signal (on/ off) for a fluidic one (flow/ no flow), then use those signals to amplify, divert or shut-off other flows. Grand, but where's the logic?

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Elon Musk's spectacular ‘Starship’ is a design straight out of schlock science-fiction but exactly right for its intended purpose, which is to shed the kinetic energy of a seventeen thousand miles per hour descent without disintegrating or rendering itself into a smoky crater, or a turbulent splash. Its final graceful rocket powered hover at a precise location over the waves is an act of engineering ballet, performed by dancing skyscrapers.

But the real drama starts a little under a hundred kilometres up where the atmosphere changes from a ghost to a wisp, which for something like Starship is about the same as slamming into a brick wall, twenty-five leagues above the sea.

When something like Starship chooses to return to Earth's embrace it can be doing anything up to 17,000 mph, and that's a lot of haste. At this kind of speed (about 25 times the local speed of sound) the airflow over the spacecraft doesn't function as you'd expect as Starship is moving too damned fast for air to ‘get out of the way’ in the normal fashion. Instead a series of violent shockwaves form around the vehicle, which redirect the path of the air passing through them, at the expense of rapid compression and the generation of a certain amount of heat.

A lot of heat!

At the high hypersonic speeds encountered by descending spaceships like Elon's characterful creation, the shock heating gets to thousands of degrees: Enough to rend the air into an ionised plasma and cut steel. Enough to obliterate almost any material, in fact! It's trial by hellfire…

Do you want to know how to protect yourself from hellfire?

1: The plasma cutter.

Necessity is the mother of invention, but genius can pre-empt it.

Robert Goddard first developed the concept of a heat shield in the late 1920s after observing meteors entering the Earth's atmosphere. This significantly predated World War 2, where the advent of liquid fuelled rocketry and the V2 ballistic missile underlined the point that war really does quicken the blood of invention. As conflict and captured German scientists gave way to the Cold War and the space race in the 50s and 60s, the issue of re-entry heating became salient at last. Aerodynamicist Von Kármán coined the term ‘thermal barrier’, believing that no material known at the time could resist the demands of re-entry from orbital velocities. 

As it turned out, Von Kármán was wrong, but it begs a question: If rockets are able to accelerate up through the atmosphere to orbital speeds in the first place, why is decelerating back down such an intractable problem? Aren't the two scenarios just two sides of the same coin?

Not quite.

For a start, a skyscraper-sized orbital rocket ascending with misleading speed towards the heavens does most of its acceleration above the air: The big booster stage is mainly concerned with gaining height rather than velocity, while the second (or even third) stage spends most of its time accelerating in the ghostlike realm of the stratosphere and ionosphere, where the atmosphere is as thin as a tax economists’ Christmas party. For example, the most common launch vehicle in the world, the Falcon 9, stages at between 70 and 80 kilometres of altitude at about six times the speed of sound. This is fast, no doubt, but not so fast that thermal protection is a big factor. The vacuum adapted engines of the second stage then accelerate the Dragon spacecraft another two and a half times to reach orbital velocity while the big booster falls back to Earth. 

And the re-usable first stage booster gets to fall in a graceful parabola from a relatively low altitude (“only” 70 to 130 kilometres) and so never ends up gaining that much velocity… only twice as fast as a BlackBird spy plane, or six times faster than a handgun bullet. No problem. 

The second stage, however, has to return from orbital velocities, which is a little more problematic…

Orbital velocity is 7.8 kilometres a second, or over twenty eight thousand kilometres per hour, or over seventeen thousand miles per hour. Or about twenty-five times faster than that handgun bullet. -Basically it’s really bonkers fast, and the only thing available to slow the spacecraft down is the atmosphere, which starts as a ghostly memory way up high but increases exponentially in thickness from one hundred kilometres altitude as the spacecraft falls.

At these velocities, the shockwaves that form around the spacecraft do more than make a loud bang: The heating of air through the shock (or just impact with the hull) is so severe that it hits thousands of degrees and is turned into plasma. Plasma that radiates powerfully, basting the fuselage in lethal heat. What’s more, the sheath of superhot ionised gas is opaque to radio waves, which means that a re-entering spacecraft can be completely shielded from communication from the ground. This was particularly troublesome during the Apollo missions, where a three-minute blackout cut the astronauts off from the ground for the most dangerous part of the mission. 

Three minutes as a meteor, and nobody in the world knows if you’ve made it or not. Trust the math buddy, because you’re all on your own. 

SpaceX managed to break the blackout curse by bouncing signals from the spaceship upwards, through its orbiting mega-constellation of Starlink satellites, allowing for something the world has never seen before: A live feed of re-entry! This led to some epic-level tooth-grinding with many of the flights, as Starship flight 4 managed to survive re-entry with a control flap almost severed from its body by plasma that had torn away the heatshield and was melting the steel frame. 

At a high enough velocity, air is pretty damned dangerous!

For a more eighties-style example, here’s the max skin temperatures experienced by the Space Shuttle orbiter during re-entry (here written in Fahrenheit), with the most vicious hotspots on its nose and belly, where 2,960F, or 1,627 Celsius is seen. This is a temperature that would melt steel, titanium or even nickel. It’s a temperature rarely seen outside the heart of gas turbine engines, and in those the superalloy blades and nozzles only survive through the application of serious amounts of cooling from highly compressed air: Something the Orbiter didn’t have access to. 

And it’s not just about peak temperatures, but also managing energy. An object at orbital velocity has to shed kinetic energy equivalent to 31 million Joules per kilogram… OK, that means nothing to anyone, but it’s about seven and a half times more energy per kg than you’d get by exploding TNT, and it all needs to be dissipated. 

Fortunately only about 1%-3% of this gets absorbed into the spacecraft itself (shockwaves knock most of the rest into the air), but that’s still enough to cook the occupants if it’s not managed: Even 1% of kinetic energy retained as heat in the vehicle is sufficient, if evenly spread-around, to raise the temperature of the entire craft by 600 degrees if it was all steel, or 74 degrees if you somehow built an all-water spaceship. Basically it’s lethal either way.

So thermal protection isn’t just about finding high temperature materials, because you also need insulation to keep all that heat away from the astronauts inside, and cooling to make sure that it stays away. This is not straightforward!

So long story short, what are our options?

2: Options, options.

You can divide thermal protection systems into two broad categories: Active & passive. In an active system, some mechanism exists to transport heat energy away from the structure and cool it, whereas in a passive system you just stack up materials that can take the heat and let them soak it up.

There is also a semi-active option, which we’ll start with: Ablators!

An ablator shield is a one-use disposable heat shield that is charred or chemically altered by the heat of re-entry and outgasses as it does so. In this way it both absorbs heat and also expels it through loss of material as the shield is ablated away. One early example of this is cork. Yes, the wood itself! 

Cork is low density and has a cellular structure of closed prisms filled with air, providing superb insulation for the structure beneath. It also forms a char layer as it’s hit by superhot plasma, absorbing the heat in an extra barrier. The char formation creates outgassing, dumping thermal energy into the air as it abrades down. This happens relatively slowly, so aerodynamic geometry isn’t badly affected, and the ease of machining, cheapness and lightness of cork has made it a valuable structural component in many heat shields.

And it’s renewable too, eco-fans! Just plant another tree.

Other more synthetic ablator shields include Avcoat (a honeycomb epoxy which chars and outgasses) that was used in the Apollo program, and PICA (a phenolic resin impregnated carbon ablator) used in the SpaceX Dragon spacecraft as well as the Stardust comet sample return mission. Ablation layers are excellent at dealing with very high heat fluxes (hence their use in the extreme velocity lunar capsules), but are mostly one-shot-&-done, not ideal for reusable spacecraft unless you’re willing to book in plenty of renovation between launches. 

And so we move to our next category: Passive thermal protection through insulating tiles & blankets! These are typically aimed to be reusable, degrading minimally within an individual flight, and so are found on vehicles like the Space Shuttle (LI-900 silica glass fibre tiles) and the SpaceX Starship  (a silica-based ceramic tile). They are designed not just for heat resistance but also spectacularly low thermal conductivity. There are videos online of people holding LI-900 tiles at their edges by hand straight after they’ve been sat in a 1,200 Celsius oven. Heat simply isn’t flowing into the person’s skin fast enough to burn them, even though the centre of the tile is white hot!

All this specialization brings drawbacks of course: If you optimize for low thermal conductivity (a LI-900 tile is 94% air) then you lose strength, rendering them fragile. We sadly saw the possible results of that with the Space Shuttle Columbia disaster, which disintegrated during re-entry due to a compromised thermal protection system, though this was a carbon-carbon panel rather than a LI-900 tile. Reinforced carbon-carbon is a carbon composite weave embedded in a graphite matrix, capable of managing temperatures over 2,000 Celsius. They were found on Space Shuttle hotspots such as the underside of the nosecone and wing leading edges. 

Likewise, tile loss on early SpaceX Starship vehicles led to dramatic re-entry failures and is something that has been continually optimized as the program has advanced.

The other drawback of reusable tiles or panels, aside from potential fragility, is complex assembly. If you commit to re-usable tiles then you need a lot of them, and you need them to be securely mounted with minimal gaps that plasma could sneak in-between. Starship, for example, has an ablative layer underneath it’s silica composite tiles, thousands of which cover the exposed belly, fins and nose section of the craft. Unlike the Space Shuttle they are standardized, which aids manufacture, inspection and installation, but tiles still add a significant assembly & inspection load to the turn-around of a reusable spaceship. 

And they’re kinda fat-looking, so you’ll have no slinky needle points on your cool new spaceship, which immediately loses you 1950s retro-chic points. Whether through ablatives or tiles, making it pointy seems to be a no-go.

And before we dive into the other forms of thermal protection, let’s explore why chonky spaceships might actually be a good thing…

3: Buck Rogers was wrong!

We’ll start with some counter-intuitive design quirks. For one, why are space rockets and orbital capsules so damned… blocky? 

We naturally assume that something designed to go really, really fast will have a certain retro sci-fi aesthetic. In short, we want it to be pointy! Fast cars are pointy, missiles are pointy, speed skaters aren’t exactly spherical, so why are the front ends of space rockets so blunt?

The answer lies in heat protection: Early attempts at hypersonic rockets were indeed pointy, on the basis that this would reduce drag and therefore heat loading… except it transpired that a slim ‘n’ sporty physique was a death sentence in the hypersonic realm. It’s just one of the counter-intuitive design quirks that dominate re-entry vehicles. 

You see, the heating effect from air at such insane speeds doesn’t stem from skin friction but mostly from shock wave formation, as mentioned earlier. The hot, radiating plasma shocks are like an oven heating element, so it’s best to keep them at a respectable distance. Sadly, a skinny frame swept back below the shock angle means that the apex of the shock is in contact with the leading edge, with inevitable results: Melty, disintegrating death. 

By contrast, make the leading edge of a spacecraft blunt and the shocks that form will stand proud of the surface as they curve around the spacecraft, keeping a handy distance between your skin and the inferno. The design feature is further enhanced by the extra internal volume afforded by fat, blunt leading edges: Make it chonky and you can fit extra stuff inside it such as heat ablative material, insulation and cooling systems. Good luck doing that on a needle!

This actually becomes a big quandary in the design of air-breathing hypersonic cruise aircraft, since unlike a fat spaceship re-entering the atmosphere, a hypersonic jet would need to keep drag as low as possible, meaning slender lines and skinny leading edges. More ballerina than rugby player. 

And skinny figures fry when they fly too close to the sun.

So far, so intuitive, but there are quirks in hypersonic aerodynamics that go far beyond a fat rocket, and we’ll go through them, from unpredictable boundary layers, shockwaves that reverse control inputs and air so thin and hot that it stops being air at all.

But first, let’s go through the last couple of thermal protection systems: Hot structures and active cooling…

4: Hot to trot!

You can’t keep out the heat forever.

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Do you care about your partner's politics? Do you even know?

The online world is funny because every now and then you see something borderline nuts that everyone responds really strongly to, like that video of the skincare company women dancing in a circle, “Gen Z boss with a mini” and all that. As far as I could see it was just some lasses having fun (and getting free publicity with a viral video; clever move!) but a weird riptide of oddballs surfaced from the frigid depths of the online world to berate… I don't know, working women, or HR ladies or Me-Too or something. I didn't quite follow it, but they were very angry. 

In a similar vein, occasionally I'll see a viral post from some woman (it's almost always a woman) stating how she'd never date a tory, or a republican, or a democrat or pick-your-flavour. I always, always fall for this because I personally only found out about my wife's politics after we got married, at an actual polling booth. I don't think we'd have gained anything by talking about it earlier, so no loss.

(She voted for Sinn Fein and Michael Lowry by the way. I know! Both of them at the same time.)

Yet there's a surreal amount of people online who take all this very seriously and definitely, definitely wouldn't date one of The Enemy. I've never encountered this in reality, but then I'm of the generation who met the love of their life by getting absolutely hammered, so the challenge was really about remembering their name rather than their political affiliation.

And just like the ‘Gen Z boss in a mini’ thing, I suspect the outrage is mostly put on. Look how picky I can be! I won't kiss you if you don't vote Liberal Democrat!

It's tribal posturing all the way down.

1: The two-minute reveal.

I was once asked in a job interview to just talk about myself for two minutes straight without saying anything about work. It's a damned good interview question if you want to see someone think on the fly, because nobody prepares for it and you end up becoming honest by accident.

Try it yourself, right now, and see what you come up with!

I talked about being a new dad, about rugby, about why I moved from the tropical paradise of Derby to Ireland. What interests me, who I met and why I'm more honest than I should be… Then the two minutes were up.

I got the job, which was nice, but later on something occurred to me: I never mentioned my politics or thought about it, even once. I guess it didn't make the two-minute cut.

And I'm not sure I'd want to spend time with someone who would bring up politics in those two minutes, because…

Because it's like saying you enjoy the colour blue. It's profoundly dull, and says nothing whatsoever about you.

2: Politics Doesn't Matter.

Sort of.

It sort of matters, because nations get bombed and built-up from politics, but it matters in the same way that organ donors matter: It's not important that the person you're talking to right now has a donor card, just so long as someone has. It's vital in the aggregate, not the immediate.

In the same way, whether ten million people vote for the Leopards-Eating-Faces party or the Intravenous-Peanut-Injection party is very important indeed for those who value faces or are allergic to peanuts, but it doesn't matter at all which way the person next to you voted. On the individual level it has zero effect on your life.

“So what!?” You might hypothetically shout. “Politics reflects a person's values! It's those values that matter!”

I'm not so sure. I've known hard-right self-declared racists who actually spend all their free time caring for their kids & parents and volunteering for community events. I've also known softly-softly compassionate lefties who were family-destroying monsters behind closed doors. Their politics told me less than nothing about them, and what's more…

3: None of life's Big Events are political.

I don't remember a single polling booth or election night in my four decades, but I can tell you every detail about the birth of my first child. And the second and the third. The piercing sound of that first cry, the intake of breath that says “I'm alive!” That instant will live with me until my dying day..

And the sleep-deprived fug in the months that follow, and the sing-song chime of the machines in the neonatal ward. “Boop-beep-boop!”

And years before this point, sat awkwardly in front of my date for the first time in some forgettable tapas restaurant, that's the kind of thing you want to figure out: What kind of person they are, and how will they handle the really difficult bits of life. -Not a hanging chad or a cross on a voting slip in a national school somewhere, but the grinding nights of exhaustion that gatekeep your ascendancy from person to parent.

That's the hard stuff.

And you need to figure out the easy stuff too. Are they kind to strangers? Can they take a knock or two without folding? What happens if they're offered a dream job that's far, far away? Do they like Corfu?

Do they have that special sparkle?

All important. Good luck figuring that out by asking if they voted for the Green Party.

You will lose friends, you will lose family. You'll bring blue-eyed smiling treasures into the world. You'll build and win and fail and lose your job and win a life and travel and mourn and celebrate. You'll wade waist-deep through the mire with the memories of ice-struck peaks fresh in your head. You will be a zombie, an energised genius, a starstruck teenager and a grateful grandparent in your time, and you'll want a partner to hold your hand as you do all of this.

The world already gives you far too many reasons to reject people, so why not give them the benefit of the doubt? Because your politics today will seem pretty stupid to you in twenty years anyway.

And because one day the failing fluorescent of a hospital ward will drain from your eyes as you look beyond the mortal world. You'll be surrounded by those you love and memories of those who went before, every one of them an echo of your life in this world.

All because, in the foreign land of decades ago, you'd asked out someone who didn't share your politics at all, because it didn't matter! And the future thanked you for it.

From the sky over our heads to the world beneath our feet, many of the advances in our shiny technological life are invisible ones. They change the firmament of the world stealthily without causing so much as a ripple and remake it, better and faster. Most of us never notice.

This is the world of materials science.

It's a kind of sorcery that makes metal sing, that makes microscopic hairs smell things, keeps crystal blades alive in the furnace and lets your car be cast in exciting shapes. It's the branch of science that makes metals face down the plasma storm of trapped stars and win, and maps the innermost secrets of our mind.

It can even get blood from a stone.

We're going to talk about a rare and difficult form of new material that's about to change our entire energy system, subtly from the inside. It does this by remaking the furnace heart of our most perfect machines, replacing dull nickel superalloys with a rock that has been convinced it can bend and live as a fabric. A class of materials so impossibly light, strong and heat resistant that they change what's possible in jet engines, nuclear reactors and power generation.

They can even help you stop your car quickly.

This is the story of Ceramic Matrix Composites.

1: The Cooling Conundrum.

In the 1980s, power systems giant General Electric had a problem.

The problem was that as a creator of jet engines it had to continually make its own offerings lighter and more fuel efficient to stay ahead of the competition. There are many ways to do this and all are tricky, but among the most difficult and effective is material substitution; swapping out a conventional alloy for something that either saves weight, does the job better, or both. 

GE realised that one of the most critical inputs in how efficiently an engine can run is at the hot bit at the back. This is where multiple turbine stages must take the fury of combustion plasma role-playing as a gas and turn that rage into motive force and power for the engine. 

To add an extra layer of difficulty, this has to be done as hot as physically possible.

You see, because a gas turbine needs to recover energy from a hot, expanding gas flow (and because you lose a lot of energy compressing it) the hotter you can run the engine the more efficient it can become. This is subject to two limits: Firstly, the thermodynamic limit is given by the flame temperature at the stoichiometric ratio (where all fuel and oxygen is consumed), which is a couple of thousand degrees celsius in standard atmosphere. In reality we usually don't run this hot.

-Because your real limit is given by materials. Nickel superalloys have a melting point of up to 1,350 Celsius, and they start losing strength before this point. Therefore to operate for years in the inferno, turbine blades, stators and shrouds must have thermal barrier coatings and be actively cooled. In the hottest parts of the engine high pressure cooling air is vented out to form a physical barrier between the metal and the mayhem.

In a typical jet engine, between 3% and 5% of the pressurised flow through the core is tapped for cooling in this way, and that percentage can be a lot higher. This a constant tax on efficiency, a tribute paid to keep the engine alive and stop it slagging itself.

So wouldn't it be nice if we could replace all that heavy, delicate nickel with something a little lighter, that can take the heat?

Like a ceramic!

2: Pottery and Power Systems.

Ceramics have many advantages. They can be extremely hard, extremely heat resistant and frequently inert. Compound metal-ceramics, like Tungsten Carbide, are used in high performance cutting tools for exactly these reasons.

Yet most ceramics have a drawback, which is that while hard they tend to be brittle and poor at handling shear stress: Pottery can hold a lot in compression, but even a small shear load will create cracks that will render it into broken shards. They are unreliable strongmen with glass jaws.

You can use ceramic moulds to cast metal, even tough stuff like nickel for gas turbine blades, but try to use that same ceramic for the blades themselves and you'll end up with an engine full of bits.

The reason for this is that ceramics are made of a matrix of strong atomic bonds, but unlike ductile metal, the structure of most ceramic doesn't allow for atoms to slide past each other on slip-planes, so they lack shear strength.

One sharp knock and… smash!

It's hard to get around this drawback: One obvious way might be to ‘alloy’ metals with ceramics and create a compound material like tungsten carbide, but this comes with a host of problems. For one, the different microstructures of the two materials creates boundaries that raise internal stress; something exacerbated if the two materials have very different coefficients of thermal expansion (which they usually do). 

So compound materials don't often work, but General Electric found a way: With a little ingenuity, you can make ceramics into a fibre composite!

This takes a little explaining. A Composite material is basically a weave of fibres (e.g carbon fibre) that's adhered -but not too strongly- to a ‘matrix’ material that fills in the gaps between the fibres. For aeroplanes and racecars that's typically CFRP, or carbon fibre reinforced polymer: A plastic bound by a weave of carbon threads, super strong and super lightweight.

So what if you could make a composite where the matrix wasn't malleable plastic, but Herculean ceramic?

A CMC interleaves ceramic fibre fabrics woven into a ceramic matrix, with a coating such as boron nitride or pyrolytic carbon that weakly joins the fibres to the matrix, but allows them to slide. By doing this, the fibres help to restrain the crack formation that usually shoots through brittle ceramic unimpeded, making the whole assembly much, much tougher and just flexible enough to be useful.

Do this and you can strike gold, creating a material that's hard, tough, can be formed into different shapes and is extremely heat-resistant. A CMC component can bring the kind of hot-flowing performance that will match or exceed nickel alloys, but at a fraction of the weight. That's pretty useful in a jet engine!

But they are very difficult to make! We'll find out why shortly, but General Electric spent a billion dollars getting CMCs to work, and that wasn't all consultancy fees and fat envelopes: This stuff is difficult!

3: Weaving Rock.

Before we make the composite, we must first make the fibre. Silicon carbide, a common CMC material, is formed into fibres by either chemical vapour deposition (CVD) onto a dissimilar thread, or else something called the Yajima process.

In this, a polymer called polycarbosilane is made combining silicon, carbon and hydrogen. The polymer is then melted and extruded through a spinneret and wound into fibres. The fibres are cross-linked (with controlled oxygen heating or electron beams) to hold them in place before exposure to a process called pyrolysis; basically, heating to heating beyond 1,100 Celsius in an inert atmosphere to strip the hydrogen from the polymer, leaving ceramic silicon carbide.

Generally speaking, if you want to wind lots of small 20 micron diameter threads, you use the Yajima process. If you want big coarse fibres you use CVD.

OK, so now you have a ceramic thread that you can weave. What next?

4: Surviving Hell.

Preceding the first use of CMCs was decades of development, which just goes to show how difficult new technology can be: Just because a demonstrator works in the lab, that doesn't mean you're qualified for a real customer product, and you're probably lightyears away from full-scale industrial rollout.

But the thing about decades is… they pass, and so CMC miracle materials hit the mainstream.

The first commercial use of CMCs in a gas turbine engine was in the CFM International LEAP engine (Ryanair regulars take note; the newest planes in the fleet use these!) Here it was used on something called a turbine shroud, which is a static component running around the inner circumference of the hot end of the engine with an abradable lining, helping to secure the seal with the rotating turbine blades. It gets ridiculously hot, and so was a good test of the material.

A year earlier CMCs had been experimentally tested on an actual rotary part; a turbine blade on a military F414 engine, which proved the concept that CMCs could go a lot further than unglamorous engine shrouds. Since then, the supersized GE-9X engine (for the huge Boeing 777X) has used them in high-pressure turbine nozzles, and GE's competitors have finally started serious R&D to catch up.

Remember, these kooky composites are a third the weight of Nickel and require less (or no) air cooling, so the further they spread, the more efficient your engine!

They're not perfect, however.

Their ultimate tensile strength isn't much different from copper and they lack much flexural strength and allowance for strain. This restricts their use and slows adoption, but they still have abilities aplenty: As well as light weight, formidable thermal resilience and a low coefficient of thermal expansion they also feature impressive compressive strength, as well as enviable impact resilience. This makes them good fits for high performance radial and thrust bearings… and, potentially, bulletproof vests.

CMCs are a slow burn revolution. Like an underground coal fire, their progress is patient, invisible, relentless and hot. The spark for the inferno came from powerplant giant General Electric, but it's spreading. With more robust manufacturing methods, and much higher temperature CMC varieties, we can expect them to spread and spread. 

Superlight, super hot and somehow… super cool? And all in the name of efficiency!

But how on earth do you manufacture them?

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There was a time when they were faintly ridiculous, like Hopium made real, cast into a metal shell by the green party to much amusement. For a while after that they ran quietly and inoffensively in the shape of the Toyota Prius, its powerplant choice somehow even more milquetoast, neither full battery nor full-throated petrol. A perennial fencesitter for the hand-wringing democratic liberals among us, it broadcasts virtue without performance.

And now? Depending on your viewpoint, the electric car is either a rich-man's tax-deductible status symbol or (if it was made by Elon Musk and his boys) the incarnation of malevolent MAGA in metal.

What changed? Absolutely nothing, except you.

Technology doesn't care for politics: It either works or it doesn't. Your toaster doesn't have an opinion about your vote, and neither does your laptop… but those of you with long memories might remember that even among computers, Apple was left-wing coded while PCs were right-wing, or at least Chaotic Neutral.

Mechanised looms were tools of capitalist exploitation, until they became boring. Trains were likewise, until they became tools of national strategy, then statist planning, then effete climate-justice performance. I'm waiting for the next big jump that lets us all regard them for what they really are: A powered box on rails that moves people, no more.

Nuclear power has had more political face-heel turns than hot meals: Right, left, right, left, marching on whoever gives it the least controversy in a given decade, and it isn't alone. Space travel was a militaristic superpower showcase, then a utopian dream, then a hand across the isle for all of humanity and now is coded as Elon-Musky right, despite just being a bunch of big sophisticated tubes to launch stuff into vacuum.

And solar power? First a bird-frying environmental atrocity, now a climate-saving left-coded techno-miracle with household names like, um, SigEnergy and Jinko. Solar is rapidly closing the political cycle and morphing again, into a neutral pragmatist's tool for well-off professionals to lower their bills (there's twenty two panels over my head right now). I'm willing to bet that it'll finish the loop as a right-coded rich man's toy any day now, for shifty libertarians to live off-grid and power their hunting cabins.

What the hell is wrong with us!?

We're busy apes when all is said and done, with all the simian baggage that implies. Our yearning to pin our identity to a bunch of unattractive people with bad suits and a political party is only natural: It's the inevitable result of frustrating our ancient tribal instincts to band together against a hostile wilderness. It's an instinct borne of a time where resources were so scant that we'd readily put arrows in men's necks to get better hunting grounds.

Yet our culture has changed over the millenia. We're no longer sprawling inter-married extended clans, not since the Catholic Church outlawed cousin marriage and set itself up as a central polity transcending clan and king… but those old instincts never went away.

Our culture changed, but we didn't.

So we're not leading raiding parties to the clan of the Five Knives after marrying a blood truce with the Soaring Eagles Clan, or whatever, but some of us are willing to smash each other's heads in over a football match. Or key a Tesla. Or post polemics on Tiktok about the libs or the conservatives or… whoever. It's all so tiresome.

Tribal monkeys, that's us.

But there are a lot of us now, and we've got much bigger spears. After millennia of arrows-through-necks, the only thing that might give us hope of breaking the cycle is the same thing that launched us into unimaginable prosperity over the last two centuries.

Technology.

Let's not ruin that by making it political.

You’d think “not much”, because one is a bloody great big killer fish while the other buses sunburnt tourists around the globe, but in reality the answer is ‘their skin’. 

This is because Lufthansa Technik has joined a long and growing list of technologists who have stopped drawing from imagination alone and, easel in hand, unfolded a nice seat in a pretty valley somewhere and took inspiration from nature. It’s called ‘biomimicry’ and it’s where you go after traditional design has become an exercise in diminishing returns, where you have to spend longer & longer to make a single advancement. -Well, nature has had longer than you to work on problems, a lot longer, and the blind watchmaker has made some pretty good watches in the last billion years. 

So we’re going to take on some natural inspiration. Go hug a tree, braid some flowers into your hair and stop using deodorant, because we’re going to do things the natural way, and find out what Gaia has come up with after a billion years with no days off.

And we’re going to start with our friend, the killer shark…

1: Sharkskin aeroplanes and banned rowboats.

The shark is one of nature’s perfect killing machines, like the crocodile or a malfunctioning stop light. It's existed for almost half a billion years and has barely changed in all that time: A blank-eyed predator with all the vivacious charm needed to hunt and kill on a flooded planet, it’s efficient, fast and studded with more senses than any creature has a right to possess. 

Never trust an animal that can sense electric fields; there’s no way it’s doing that for something nice. 

Anyway, the shark is also known for being hydrodynamically slippery while also being as rough as sandpaper. If you’ve ever felt sharkskin you’ll know what I mean; unlike mucus-covered bony fish, a shark’s skin is directionally rough as hell, which doesn’t feel like an adaptation you’d expect on a fast-moving ocean predator. -Yet it is; a drag-reducing evolutionary trick born of million of years of trial-&-error, whose outcome is razor teeth sinking into an Aussie surfer. Strewth!

Shark skin is made up of a series of backwards-facing V-shaped scales called ‘dermal denticles’, which look like tiny teeth, and a skin of teeth to propel a creature with famous jaws is certainly on-message. These scales make a shark pretty well armoured, but they also do something else, which is allow for efficient, silent swimming. 

All predators live on a delicate balance between energy-out and energy-in, and their success is dependent on riding that natural knife-edge. Energy spent swimming is wasted, meaning the shark has less time to find its next meal and keep on going. In addition, the shark needs to be stealthy and take its prey by surprise before the final surge. These two things taken together create a very good evolutionary incentive to reduce drag and water-disturbance as much as possible. 

And so shark skin; a sneaky microscopic adaptation that brings out the best in this beast of the deep, and can be repurposed for use by us, too.

Lufthansa Technik recently qualified a special coating that can be applied to the body of airliners and takes inspiration from the shark: The ‘AeroSHARK’ film uses a series of riblets, tiny ribbed flanges only 50 micrometres high that align in the direction of flow along an aeroplane and reduce fuel burn by 1%. This doesn’t sound like much, but 1% is huge: It’s what the entire aerospace gas turbine industry, with its billion dollar budgets, manages to eke out annually in fuel efficiency improvements, and here it’s been delivered by a transparent film stuck onto a plane like a glorified wall poster. 

The way it works is simple enough, though it takes a little explaining: Flow over a surface generates a ‘boundary layer’, or region of slowed airflow immediately adjacent to a surface. This creates a velocity shear which steepens as the flow continues: Make a surface big enough, and the flow fast enough, and the shear forces will overwhelm the natural viscosity of the fluid (in this case air) and transform it from a nice clean laminar flow into a choppy, whirling turbulent one. Turbulent flows are good at transmitting momentum, and very draggy.

They are also open to influence at the boundary layer.

Riblets, grooves 50 millionths of a metre high, act to restrict the formation of the tiniest turbulent eddies in the spanwise direction (at right angles to the flow) at the very lowest level of the boundary layer. Not only does this help reduce turbulent mixing, but it also impedes spanwise flow and helps to straighten flow over the wing at the lowest limits of the boundary layer. 

And the result: Lower drag. Bravo to the big fish!

And riblets aren't just a recent invention, or limited to aerospace, for they've been around for decades in marine applications, where they're even more useful! Unlike the 1% efficiency saving on the already well-optimized Boeing 777, applying riblet tape to rowing boats or yachts can reduce drag by a much more impressive 3%-5%. That doesn’t sound like much to you or I, but to an elite sportsman it's the razor-thin line between losing and the winner's podium.

Which might be why they've been banned in competitive rowing.

So the next time you moor yourself to the back of a speedboat and get pulled by a parachute into the sky of some tropical paradise, take a look at those grey shapes far beneath you, visible where fins cut the surface. Suppress your shiver and give a nod to the sharks who, ancient and unchanged, are the muse of engineers.

But maybe ask the boat's driver not to dip your feet in.

2: Heat Exchangers and Butterfly Wings

Heat exchangers aren't an obvious choice for biomimicry. With their monolithic figures, complex tube-run interiors and blood running with hot water or chemicals, they seem like the antithesis of life: Brutalist industrial totems extolling the virtues of order and power.

So would you believe me if I told you that a heat exchanger used biomimicry from a butterfly?

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<insert rent-control here>

How many times have we heard that? Often from people who presumably never had to wait for anything as children. I wanna wanna lollipop now mama! NOW!

Urgency has its place, and sometimes there really isn’t a good reason for something to take a long time and so you need an impatient little bastard to cry foul and hurry things up. Elon Musk presumably wanted lollipops quickly, and that seemed to work out well for him, so why not the rest of us?

Well, what if it’s not a lollipop that someone wants, but clean electricity, or clean water, or a redesigned city? When Parke Neville designed the water system for Dublin city and the creation of multiple reservoirs in the mid-19^th century, he wasn’t setting out to break speed records or even supply the city that existed then, but spent years creating a clean water network for a Dublin city the size of which wouldn’t exist for another century. 

When the centre of Paris was torn apart and rebuilt by Haussmann under the orders of Napoleon III, it was a project that displaced thousands, caused uproar and took almost two decades, but created the majesty and wide boulevards the city of lights knows today. 

And now? As recipients of millennia of human progress and centuries of engineering wizardry we can rend atoms themselves to make our morning cuppa and declare things like “There’s no point building nuclear power, it takes too long! There’s a climate crisis and we need action now!”

(Cue a rushed and poorly-functioning compromise.)

It’s a thought-terminating cliché and we really should know better, but we hear it all the time. We hear it whenever we sell-out for a quick buck or fail to plan for the future. We saw it when Orbex, a small private space launch company in the UK with cracking technology, was allowed to fold because nobody in government saw the benefit of planning for the decades ahead. Or possessing any vision for the future beyond the next headline. 

We see it whenever someone turns down a plan for trams, light rail, or a subway with “Why? It’d take years and we could just buy more buses now.” (That's Leeds and many other UK cities, for those who missed the reference.)

We see it when we fudge the numbers for the next quarter instead of owning up and fixing the problem. We do it when we buy instant meals instead of ingredients because who has the time?, and we call for it when we demand that the government give handouts instead of building infrastructure.

It's called time preference. If it's high then it means you value the now a lot more than the later, and prioritise accordingly. If it's low then it's the other way around.

We start our lives with a high time preference, because children aren't patient at all. They need to learn that skill, and sometimes the environment doesn't make it easy, but it's vital: A low time preference is a key predictor of life success. It's the ability to inconvenience yourself today to help a stranger in the future.

That stranger is you, of course. That's the metaphor.

A low time preference is a prerequisite for all strategy, and most life success. It's the grit to build a career, the planning to buy a house, the sacrifice to raise children. It's why the strategists win at life, and all the games of Go.

But that low time preference is cultivated, and it can be killed.

If the environment is chaotic or dangerous then a high time preference makes sense, because you can't plan for the future amidst chaos. Warzones don't cultivate well-adjusted societies and domestic war zones don't cultivate well-adjusted people.

Entire cultures can have high or low time preferences too. Low-trust societies, where instability is the rule, incentivise short-termism. Poverty destroys the future, while stable high-trust societies like the ever-smug Scandinavians build it. 

Chaos begets chaos, and order begets order. It can be a virtuous cycle.

Or a destructive one. The Germans are a characteristically conscientious bunch, so the Weimar Republic's hyper-inflation between the wars must have hit them hard: Every man that had planned for his family's future, scrupulously sacrificing, would have seen his savings wiped out by the chaos of an out-of-control currency. Between this and the inter-war settlement, the sense of betrayal must have been fierce, wreaked by a high time-preference world thrust onto a society wedded to order and planning.

Little wonder they answered the call of a dangerous populist. Beware the orderly person thrust into chaos!

And what of today? Our highest-trust, lowest time-preference societies are in a strange kind of bind. The same nations that brought about the Messmer Plan (a two-decade nuclearization of French electricity), that drilled for offshore oil at the limits of technology and laid down motorway networks and Concorde seem scarcely able to repeat those feats today. We are stuck in a short-termist pincer, being pinched to death. On the one side, the faux-rationality of the spreadsheet class and the quarterly cashflow statement. On the other side, the siren call of social media and the TikTok-ification of our attention spans.

And now, like the rental crisis in Ireland, electricity markets across Europe and transport and housing everywhere in the Western world, we shy away from the infrastructure that we'd once have built and instead pledge handout after handout. Buying people and votes one day at a time until the whole awful edifice collapses in on itself. 

Just so long as it doesn't collapse today.

Were we always like this? Maybe, but it's hard to be sure. Perhaps we were no more patient decades ago, just less encumbered by paperwork.

Or perhaps we really have begun a slow shift to higher time preferences and less social trust, as we lose ourselves in atomised microcosms, delivered by dopamine. Less patience, less community, fewer kids and more Self. Inward-looking and fixated by the minute, more and more, no longer building because we forgot that it's an option. 

It's all about the next-year commitment and not about leaving your grandchildren something.

Hopefully this is just grouchy dad-vibes and I'm wrong. Hopefully our time horizons aren't really shortening, because if they are then we're in a heap of trouble: The Western world's big problem is infrastructure, and that requires commitment over time.

We're still living on the infrastructure of the old world, put down by men with more vision than you or I, but it won't last forever. One day it'll fail and crumble, the cracks in the concrete spreading, the paint falling away, leaving the ruins of a world that thought in centuries and only lasted that long.

So let's ignore the 5-year investment return for once and build something for our children's children. 

Let's build a house.

Let's plant a tree, a forest.

Dams and river defenses.

A nuclear power plant.

A city on Mars.

The future. It's for them, not us.

“Is anyone out there!?”

We can't handle infinity, or being alone, but we know these places aren't really infinite, so most of us resist the temptation, clamp our lips shut and hold our counsel to the dark places.

After all, there's always the fear that they might reply.

And so it is with the night sky, with a few differences. Firstly, while the universe may be finite, it’s unhelpfully big: There are between a hundred billion and four hundred billion stars in our galaxy alone, which is a number so inconceivably massive you'd thirst for a stiff drink just trying to hold it all in your head. And with hundreds of billions of stars, there must also be hundreds of billions of planets.

If even a tiny proportion of these were, Goldilocks-style, just right to support liquid water, that's hundreds of millions of worlds in this galaxy alone that could potentially support life, and with such geologically overwhelming odds, the question isn't really why we hear nothing when we scream into the void…

…The real question is why the void hasn't screamed at us first.

1: Alone in a vast, locked, room.

The question we’re trying to answer is “are we alone?”, and the vast majority of creatures in this world simply wouldn’t care. At the end of the day we're clever apes, and this comes with a locker-full of excess baggage that doesn’t apply to anything else on this globe. 

For one, we’re social creatures. If you want to drive a human being insane, you deprive them of company. If you want to make a person feel threatened, you deprive them of support or communication. We don’t have overpowering physiques, sharp claws or lethal venom, or many defences at all which work on the individual level, past simply ‘throwing a rock’, so we need our buddies to survive. 

Secondly, we’re intelligent, which means we can think in abstracts. It’s very unlikely that the wandering albatross throws a glance skywards and views the infinity of heaven with a weary sigh, but put a human being in the open to camp under pinwheeling stars and our minds are drawn to The Question. 

Is there anyone else out there?

Perhaps I’m wrong. Perhaps Orcas in the Arctic take a break from traumatizing seals to gaze upwards with a sense of spiritual ennui. Or perhaps it goes in the opposite direction, and hundreds of lightyears away a sentient slime mould oozes through an incredible city, casually regards the glory of creation and doesn’t give a shit. But until I’m proven wrong we’re looking skywards and wondering, and that creates a problem because there really, really should be something to see. 

You see, as mentioned before there are an absolutely colossal number of stars and planets, so logically there must be life out there somewhere, and if there’s enough life in enough places then presumably there’s intelligent technological life in a few places as well. Except we don’t see them, despite looking, and we’re not silent, so there’s no reason to believe that they would be.

High power planetary radar pulses from specialist facilities are potentially detectable up to 12,000 light years away (about one-fifteenth the width of our galaxy) with equipment like our own radio telescopes, and that potential radius would cover billions of stars. We only occasionally emit signals so powerful however, and they’re directional, so you’d have to have them pointed directly at you. Deep space transmissions used for communicating with craft such as the Voyager deep space probe are maybe detectable out to 60 light-years, which would cover thousands of stars, though again these would be directional signals. Omnidirectional signals such as TV and radio broadcasts can be detected by the very best current radio telescopes out to a distance of 16 light-years, or 70 star systems. There is ample time for an ET in the local neighbourhood to blast back a message saying “Stop showing so many bloody Friends reruns! It was never that good in the first place!”

So we’re not exactly stealthy. Why can’t we hear anyone else, or even see them in the sky?

Space travel is hard, interstellar travel might be ridiculously hard and interstellar colonization could be damned near impossible, but if it’s possible at all then all it needs is one civilization capable and willing to do it, plus time. The sky should be thronging with the techno-signatures of intelligent life, yet it isn’t. What is going on?

This is the Fermi Paradox.

I’m not here to solve Fermi, because nobody anywhere has the information needed to do that, but I am going to lead you on a pleasant walk through the most plausible explanations, and recommend some good fiction on the way that you can flick through if you want. It’s nice to take your imagination for a wild ride, once in a while.

So, what do you say: Shall we go find Fermi?

2: Shouting at locked doors.

The first solution could simply be: We are all there is.

Perhaps life really is astonishingly rare and unlikely, the chance formation of order from chaos a cosmic freak that requires an entire cosmos to stack the decks. We don't know how it happened, so we can't be sure.

Or maybe life is common, but technological life is the real super-rarity. There are no scintillations out there in the black, because the spark of extraterrestrial intelligence is just too dim: Dull creatures browsing algae and slime, suckling on rocks and turning rheumy eyes to a heaven they can never comprehend.

It's impossible to know if either of these are likely, but I feel that both lack a certain drama. The all-human galaxy is a narcissistic sort of vision, but one burdened with terrible purpose: If we really are all the intelligent life there is, then we owe it to the universe to tend the spark of sentience and never let it go out. There are cruel things out there in the black, and we must never succumb to them!

That said, surely the all-human galaxy leaves fiction a little monochrome, a little lacking in novelty? You'd think so.

You'd be wrong. Frank Herbert's ‘Dune’, for example, is a dense masterpiece where humans have twisted themselves into becoming alien to each other, characters speak in their inner voice like this and, lacking computers or AI, mankind has spent thousands of years training the mind. The action centres around the desert planet Arrakis, source of the mind-altering Spice needed for interstellar travel, where colossal sandworms and hostile natives make for danger in a brutal world riven with treachery: Treachery which is every bit as tangled as you'd expect from feudal leadership castes bred for cunning over millenia.

It's ferociously dense and hard work at times, but Dune is worth your time without a single alien in sight.

Except for the worms, I guess.

Or perhaps we're not alone, but stuck in a jail cell of relativity, the door locked by lightspeed. It's possible that there's intelligent life throughout the cosmos, but the difficulty of crossing the interstellar gulf is so spectacular that nobody anywhere tries it and succeeds.

I've written on this before, and the reality is that interstellar travel isn't actually impossible, that there are well-studied ways of making it happen, but they are all way up on the civilizational difficulty dial: It's playing on permadeath God-mode, no fast-travel allowed.

But it's not actually forbidden.

For the locked-jail-cell interpretation of Fermi, where all civilizations can do is shout across the ether, you don't need interstellar travel to be prohibited by physics. You merely need interstellar colonization (as opposed to probes or warheads) to be so unlikely to succeed that a hypothetical colonization wave never gets off the ground, or ebbs to glowing embers after a couple of lucky attempts.

It's hard to find fiction in this category, though you could claim the movie Species is an example: An interstellar communication is received and it's a genetic code, with instructions on how to make an alien/ human hybrid. We then do exactly that, like the gullible mugs we are, and the resulting creature escapes and attempts to breed, with predictably horrifying results.

But in a way, the schlock-horror of Species is a refutation of the lightspeed-jail hypothesis, because there are ways around it. For sure, we humans are poorly equipped for interstellar colonization; we need too much stuff, too much food, too much oxygen and we're bulky, fragile creatures who reproduce slowly. Any putative human colony ship would be a colossus unless the colonists travelled as sperms and ovum. Or a sequence on a flash drive. Or a signal beamed to another world.

A civilization of alien slime moulds, or similarly robust creatures, might have no such limitations, and yet they're not here.

To end this section and move onto the next Fermi solution, let's recommend my favourite work of fiction that deals with the ‘all alone’ scenario: Stephen Baxter’s Time.

In this, the space entrepreneur Reid Malenfant, an Elon Musk-style disagreeable genius, mounts an expedition to the asteroid Cruithne. The experimental mission is piloted by genetically engineered intelligent squid rather than inflexible robots, and finds an artifact that gives glimpses of the distant future: A future where the stars are stained green by the blossoming of a vast galactic civilization. Hope, perhaps, in humanity’s manifest destiny? A tonic given to a cynical population in a time of decline.

It is not to be.

The squid reproduce and take matters into their own tentacles, opting to colonise ice-rich Cruithne for themselves. Meanwhile, something is happening on Earth, as a scattering of super-genius children are born; the birth of a new type of human being inspiring both awe and superstition. 

Belatedly, humanity realizes that its destiny really is to germinate life that spreads throughout creation, but it won't be us doing it. This gives pause for thought in today's world, where interplanetary ambitions are rising once again, alongside the mewling cries of an infant silicon sentience. The first being to reach the stars might come from us, but not be one of us.

Now, what about the other solutions to Fermi? There are darker ones out there…

3: Crying into Dark Forests.

Picture an infant, cold and alone on the bracken, crying into a forest at night as the wolves circle and approach her.

Probably the most chilling resolution to the Fermi Paradox is that the aliens are out there, but they've learned to stay quiet!

More fool us, as we bicker into the radio spectrum.

There is a certain logic to this, since if you can traverse the space between stars, it's easier to send a warhead or kinetic impactor than a colony ship. If you don't know the predisposition of the creatures you've found at Alpha Centauri, or wherever, it might make sense to play it safe and weld them all to the bedrock just in case.

And there's energy levels to consider: If you're capable of traversing interstellar space with any sizeable payload in less than a human lifetime, that means you're already making something move so damned fast that there'll be a serious crater when it impacts.

So far, so logical, but perhaps we're being too hasty?

The Dark Forest is borne from our own evolutionary past, where there really were wolves out there, and worse besides… the Rape of Nanking wasn't conducted by wolves but human beings after all. Sometimes the very societies that prize peace and harmony for the in-group are capable of mind rending atrocities against the out-group. There are enough examples of that just in the last century.

But that doesn't make it a rule of life. Our closest relatives, the chimpanzee, certainly wage war as we do, albeit not quite so terrifyingly. But Orca don't do this, and neither do dolphins, even though they're horrible violent bastards in different contexts. Perhaps it's luck of the draw, then? If you encounter an alien civilization, are they more simian or cetacean?

And perhaps we should shoot first, just in case.

There are many, many examples of the Dark Forest in fiction, most notably the Three Body Problem series by Liu Cixin (recommended!), but to me the quintessential example is Greg Bear's The Forge Of God. 

In this, a book that starts with the sudden disappearance of Jupiter's moon Europa, the overnight appearance of small mountains and cinder cones around the world signifies the arrival of an extraterrestrial force. In this cold war-themed book, what follows is the exploration of a particularly nasty resolution of the Dark Forest, as it emerges that Earth has become the target of self-replicating Von Neumann machines whose sole goal is planetary destruction. The Killers, a race that is never seen and might be long dead, released these aeons ago to clear out the forest by annihilating everyone else in it: An extreme paranoid response that has a certain grim, human sort of logic.

The wolves are getting closer and we didn't shut up in time…

Is there a nicer solution to Fermi?

4: Speaking Truth To Jellyfish.

Perhaps the reason we haven't seen or heard a single alien is because they're just too… weird. Maybe we wouldn't recognize what they do as talking, see any intelligence in them or even notice that they're alive at all.

We have no way of knowing if carbon-based protein structures are the most likely form that life could take. Perhaps we're a minority in the universe and the throng of civilization all around takes the form of endlessly patient silicon-based creatures, or gas giant dwellers, or deep-space computers yearning to be cooled to absolute zero. 

Or maybe it's life forms like Stephen Baxter’s enigmatic enemies, the Qax; vast self-organizing turbulent cells in roiling oceans or proto stars. Things so alien you could look right at them and never recognize them as life.

A fun example of this, with plenty of hijinks and space operatics, is Iain Bank's The Algebraist, where to stop a war the protagonist must venture into the atmosphere of a gas giant planet to talk to the quixotic ‘Dwellers’. These are an alien race billions of years old that keep to themselves and are… very… very… slooooooow. The Slow Seers that talk to them must bring their bodily processes to almost geological levels of sloth, while the world outside races on.

Or in Wil Mccarthy's novel Bloom, we see the apparently lethal Mycora, a nanotechnology plague that has eaten the inner solar system and rains spores down on humanity’s refuge in the outer system. The nanotech bloom is thought of as a dumb self-replicating killer plague, until telescope surveys discover something odd on Venus, now consumed totally by the Mycosphere: A clearing, where human shapes walk and live. 

Could it be that the computational infinity held within a solar system of self-replicating processors has an intelligence, even a civilization of its own? And if so, what became of the humans swallowed by the nanotech bloom?

But before we go scouting for gas giant philosophers, or sentient nano plagues, perhaps there's another explanation.

Maybe the aliens are all out there looking in, and we're just not meant to see them yet.

5: Exploring The Zoo.

Ever looked into an aquarium and considered how the fish feels about this?

At least the fish gets to occasionally see you walk past and stop, placing your gross distorted face against the glass to smile and point in a gesture completely lost on anything aquatic.

You get where I'm going with this. Perhaps, just perhaps, we're being watched and studied in secret, trapped in an enclosure the size of a planet while things watch us from afar. It's one of the most conspiratorial of resolutions to Fermi, and somehow even more narcissistic than the one where we're all alone. What makes us so special that we'd be a zoo exhibit anyway?

Maybe we're a bit disgusting, or primitive or dangerous. Maybe it's all a simulation, or perhaps we're a harvest.

It's one of the less likely solutions to Fermi in my opinion, but narratively rich. My favourite ‘Zoo’ novel is Iain Bank's State of The Art, written from the viewpoint of the crew of the starship Arbitrary who visit Earth in the late 1970s. The Arbitrary, a character in its own right, is a superintelligent AI and its crew is very nearly human, needing only minor alterations to pass unnoticed on Earth. The novel is made more delicious by using characters and settings from Banks’ ‘Culture’ series of novels, depicting a vast AI controlled communist space-utopia, and viewing Earth through their eyes. The crew are divided between those who want to ‘fix’ the flawed human civilization from the shadows and those who would formally contact it, bringing it into the Culture fold.

The crew are likewise split between those disgusted by our riven and sordid state in the late cold-war, and those who fall in love with Earth, choosing perhaps to settle here for good.

Well, you would, wouldn't you?

6: Here We Go Again…

A very, very unlikely solution to Fermi, but one that yields great narrative potential, is that we're all in this together: There are thousands of intelligent technological civilizations arising at the exact same time, each one the first within its local sphere and so looking on the world with new eyes. Everyone will meet, in the foreseeable future, in a grand competition of equals.

How very convenient!

Given the age of the universe this seems impossible without a precursor event, such as a galactic-level mass extinction that periodically wipes the slate clean, so every new civilization that builds itself up out of the rubble encounters the Fermi Paradox in the same way.

An example is one of my absolute favourite works of fiction, Stephen Baxter’s Space, which deals with exactly this premise. In this, humanity is stunned to find signs of an alien presence in the outer solar system. The cybernetic ‘Gaijin’ are contacted, and reveal that they entered through an ancient fast-transit portal far beyond the orbit of Pluto. Recurring adventurer Reid Malenfant visits and passes through the portal, discovering that it's part of a grand network that predates both humans and Gaijin.

Meanwhile, other explorers start finding the wreckage of ancient terraforming attempts within our own star system. Technological leftovers of events hidden in history, pointing to an unsettling realization: All of this has happened before!

As Malenfant bounces back-&-forth through the portal network, the relativistic time dilation provides a narrative lens to observe the evolution of human society in a series of time-lapses. Decades, then centuries, then millennia pass and our initial advancements become lost potential as we regress into scattered colonial outposts. Meanwhile the stars turn green or start to flare as the colonization wavefront of every other species gathers pace towards us.

And, at the end of it all, Malenfant must journey out to find the source of the Great Reset and see if he, and humanity, can find a way of closing the Paradox forever.

7: The Great Filter.

There are countless solutions to the Fermi Paradox and I invite you to warm up your imagination-muscles and conjure your own! All we know is that a sky that could be full of life is, unaccountably, silent.

Maybe the other Earth-like worlds are all continuous unbroken oceans. Perhaps abundant metals and liquid water almost never coexist on a planet together and so a civilization with jet engines and the microwave oven never gets off the ground.

Or perhaps there is a Great Filter that stops almost all life from reaching the space-faring stage. This filter might be in our past; simply the unfathomable good fortune required to create life in the first place, in which case we have little to fear.

Or it might lie in our future, which means we have to pass through it, whatever it is. Perhaps the first questing tendrils of true Artificial Intelligence into the genetic code will answer us with a genocidal plague, or our swelling numbers will bring our end with an almighty psychic scream, or it'll turn out the dolphins were in charge the whole time.

Or perhaps all this will be answered tomorrow, when the spreading sphere of our radio emissions finally crosses a civilization capable of answering in kind.

And on all the television screens, across our eyes and the skies themselves, a message.

We are here. We are not alone.

Would you feel better after reading that? Or worse?

That applies even if the factory builds pacemakers, like the one I used to work in. Life likes irony.

How do you check the health of a factory?

You'd think that if raw materials are going in and sold products are streaming out then everything is rosy, but that's not always the case. That big pile of goods out back might just be fat in the arteries, killing the patient.

Let's roll back: A factory to most people is just an unappealing box that makes widgets, and for all the hand-wringing about de-industrialization, the average person doesn't care that most of them are in China now. After all, who wants to work in a factory, right? This is an appealing thought, but wrong.

For, you see, a factory has a soul.

In its habits and early-bird rising, a factory is a living creature, and you need to see a few of them before you start to understand how they work, and the kind of things that are good, and bad, for them. For example, a gigantic pile of finished product standing ready to ship is often not a symbol of industrial muscle. That massive pile of 22-inch touchscreens, or whatever, is often just fat. And just like fat, enough of it can kill.

But what makes it prosper?

Every engineer who works in a factory knows the importance of yield and OEE. This is the obvious stuff, so let's define it here: Yield is just the percentage of conforming product that makes it through a process. On a factory scale, yield tells you how much of your input ends up as usable output and not scrap. Higher is better.

OEE, or Overall Equipment Effectiveness, is another obvious one. It multiplies yield by the percentage of available time a process is actually active and then again by process speed relative to design speed. This tells you how efficiently you're using your assets.

There are other measurables, but these are the big ones that engineers tend to micro-focus on. The one that's often missed out is the big pile of 22-inchers out back, which tells us:

“Are we actually building what the customer wants today?”

A pile of finished goods means that you made something that can't immediately be sold, and what's the point in that? How does this happen?

Every day your customer buys or orders stuff, and the signal to replenish shelves shuffles down to you, the factory. Once a day or perhaps once a week, a list: “This many thingies of these varieties, ASAP. Thanks!” This is the demand signal. Now if a factory can fulfill that demand signal by making the right widgets before the next signal arrives, and get them on the truck outta here, it's doing great and there's no need for a big pile. You make, you ship, you get paid. Perfecto!

But if the factory can't respond quick enough, then the only way to respond quickly to the signal is to have a big pile to pick from, and that means that you have to guess what goes into the pile: A reactive, 100% accurate signal is replaced by a raw-guesswork inaccurate one way up the chain, with a buffer in the middle. This is how you mess everything up.

And here's the dirty secret: Factory products spend most of their time waiting around. Actual processing time is pretty short for most things, so if it takes a week getting raw materials to become a shiny new widget, I guarantee that most of that time is spent in a queue somewhere.

In short: A big pile at the back implies lots of little piles all over the place, hidden from view. You can deny it, but it's there. A good step is to conduct a value stream map (VSM): Modern MES systems (think ‘factory IT’) make this a breeze, with timestamps for task completion on each batch and serial number. Run this over a week for a family of products, strip out the known process time, and what remains is queue time.

The magic bit: If your accumulated process time is less than the gap between your customer demand signals (it usually is), then all you have to do to make your factory work twice as smoothly is stop things sitting around so long between operations.

Because it's not just about process efficiency. It's also about product flow.

So you only make what your customer tells you to make.

Putting it into practice.

“OK, that's lovely, but have you actually done this for real Jordan?”

Why yes I have, Mr. Hypothetical Questioner! Would you like to hear that story? ‘Course you would!

A few years ago I worked in a dull brown rectangle of a place next to the little town of Clonmel in Tipperary, Ireland. This dull brown rectangle is special because it makes life-saving implantable pacemakers, defibrillators and neuromodulation devices, thousands of them a day. It's one of those ignored places that props up our entire world in secret, that you'd never know about if someone didn't point it out. There are lots of dull boxes full of secret miracles in this world.

Anyway, while I was still a newish engineer there I was introduced to a problem:

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So far, so flared trousers and tie-dye. Now let’s insert the engineering.

The inside of a jet engine’s turbine stage is just about the most hostile environment you’re ever likely to sit next to. Inside, a combustion-powered hurricane nearing the speed of sound roars at temperatures that can melt just about anything, including the engine itself. The turbine blades that live here survive only because of constant film-air cooling from chillier bits of the engine, delivered through a labyrinthine heart and tiny, subtle vents. They can rotate in excess of two hundred times a second and pull twenty thousand g’s of acceleration, which is the equivalent of you, dear reader, being tied by your bootstraps to about 1,600 tons. You’d be torn to pieces in an instant, but the Nickel superalloy turbine blades that fly us to sunny islands don’t, and they can live happily in an environment about two hundred degrees above their own melting point.

And as if that wasn’t enough, a single high-pressure turbine blade in an aerospace gas turbine engine can generate one thousand horsepower, which is the same as a Bugatti Veyron, delivered from something not much larger than your thumb. How in heaven’s name can any creation of man do such a thing?

Well one answer is that this clever little blade isn’t what it seems, for under its dour face is a single perfect crystal.

Want to know how it’s made?

1: Hot summer days in the PCF.

Yes, it’s another anecdote from my days in Rolls-Royce. Settle in and get comfy! You’ll feel comfier than I did in my time at the Precision Casting Facility anyway, because that place was a furnace.

(Ba-dum-tsssh…)

A huge uninspiring windowless block of a building, the PCF was a summertime heat trap, filled with fire and exertion. It was the type of place where if you had a desk fan you’d best write -no, carve your name on it, because it’d disappear in the scorching evening, stolen by the night shift to make someone’s shop floor hours bearable. Guard your fans, or else get used to sweat. It’s up to you.

The Precision Casting Facility’s purpose was to cast the metallurgically & dimensionally perfect turbine blades that Rolls-Royce needed in its jet engines; the creatures of the flame, who would graduate from the mild simmer of the PCF to the screaming inferno of the jet, to live forever more. Once casted, etched, inspected, barrelled and prepared they’d then move on to the building next door, the much fancier Turbine Blade Facility, where the blades would be machined, the impeccable cooling features added, load-bearing fir-tree features shaped, and thermal coatings applied. Us guys in the PCF were the unglamorous front-end, but we did get to apply our own brand of sorcery, which was the creation of single-crystal blades made out of Nickel superalloy. 

Serious engineering, for serious people!

But before we get into the manufacturing process behind these jewel-like creations, it might be worth taking the scenic route and explaining exactly why we’d want to cheat metallurgy so. There is a very good reason…

2: Crystals, crystals, everywhere.

Find something metal, right now!

Maybe it’s a wedding ring, maybe a hubcap, maybe it’s part of your phone, or a knife & fork or… whatever. It may look smooth and continuous, but in reality a metal is made up of a vast number of tiny crystal grains, all pushed up against each other. These can be all sorts of sizes and orientations and they have a huge effect on its behaviour. 

A crystal is essentially a lattice in which the atoms are arranged in a particular orientation. A group of crystals arranged in the same direction form a grain, whose growth is prompted by a number of physical interactions, but mainly when the metal first solidifies from a liquid state. 

There’s no rule stating that all these crystals should line-up, so they usually don't, and when two un-aligned grains butt up against each other they form a grain boundary. These boundaries are crucially important, because they impede the motion of discontinuities through the metal and directly affect its strength and plasticity. 

Let’s explain.

Inside every grain is a bonded crystal lattice, but within this are also dislocations, aligned crystals that aren’t bonded and so can move up & down along the plane of the molecular lattice. When you twist or bend a metal, you’re not actually stretching molecular bonds but instead moving billions of these dislocations up and down. This takes some thinking about, but the critical thing is what happens when one of these travelling dislocations meets a grain boundary.

When they meet a boundary, because the angle of the slip-plane has significantly changed, they tend to stop and pile up. They can still propagate to the next grain in line, but it takes a serious stress concentration to do so, and the result of this is that the more grains there are in a metal, the stronger it is, both in terms of ultimate yield strength and also fatigue strength, as cracks also find it harder to propagate through a material with lots and lots of grain boundaries. 

So: A few big crystals means more plasticity and lower strength. A large number of teeny-tiny crystals means more strength. The number, size and orientation of crystal grains in a metal can be influenced by heating & cooling (crystal growth usually happens when cooling from elevated temperatures) and by work or impact on the metal, which also encourages recrystallization. This is one of the primary levers engineers have to tweak the mechanical properties of the built world… And the lever is probably heat treated, too.

At the atomic scale, the inside of a metal can be a complex and dynamic place!

So what has this to do with jet engine turbine blades? 

Let’s jump back from the metallurgy, just for a second, and consider what a turbine blade has to do. These bad boys sit in the insane backdraft of a super-hurricane furnace just behind the combustion chamber and have the unenviable, -but deeply impressive!- task of translating the expansion of the hot exhaust air into mechanical energy, to spin the shafts that spin the compressors and fans that power the whole shebang. There are typically two or three stages of these: A high-pressure turbine stage (which operates the high pressure compressors), an intermediate-pressure stage (for the IP compressors) and a low-pressure turbine stage (for the big fan at the front of the engine). Generally speaking the low pressure ones are bigger, cooler and slower while the high pressure ones are smaller, faster and crazily hot!

And they have to be, because the thermal efficiency of a gas turbine engine is linked to how hot you can run it! At the ideal ratio of fuel and air (the ‘stoichiometric ratio’, where all fuel and oxygen is consumed) you get the highest burn temperature, but most engines don’t run stoichiometric as the temperatures involved would slag the engine. So they get as close as they can, and use a combination of cooling air, thermal barrier layers and impressive metallurgy to survive hell. 

So, dear reader, what type of crystal structure would you expect to see on a turbine blade?

From what’s been said so far, you’d be forgiven for assuming that the ideal structure would be lots of small grains with an equiaxed structure (grains orientated in random directions). This would presumably give the most strength, meaning that you could support more force with less blade, which is good for something that has to fly. 

You’re almost right, but for the hottest turbine blades there’s an exception: If you subject a metal to constant load over long periods of time over 40%-50% of its melting point then you get a phenomenon known as ‘creep’, where molecules within the metal slowly rearrange themselves under constant load. Grains re-orientate and slip past each other, resulting in a lengthening and twisting of the object under tension. For a jet engine’s turbine blades, which duh, really do operate at high temperatures and constant ridiculous load, this is A Big Deal. Blade lengthening would ruin design clearances, lower efficiency and potentially cause failure. 

There are a couple of ways to minimize creep. One of these is to align the grains using directional solidification, introduced by Pratt & Whitney in the 1960s and creating a lattice of nifty-looking columnar grains, all in a line. 

But the other even better way is to simply cut out the middle man completely: If the entire turbine blade is one giant crystal then there won’t be any grain boundaries at all, meaning no grain re-orientation is possible and the fastest modes of metal creep are eliminated at source. This was also developed by those eggheads at Pratt & Whitney, before being introduced to the unique superfast J58 engines for the SR71 ‘Blackbird’ spyplane. Well, it figures that you’d need something special in a plane designed to out-speed a bullet. 

And now they’re everywhere! You’ll see them in both military and civilian gas turbines, and no wonder: Make a blade super high-temperature and creep resistant and you can run your engine hotter, with better-fitting blades generating more power with less. This means more kilometres per kilo, more bang for your buck and, crucially, lets you cheaply fly somewhere sunny in winter to turn your skin a fetching shade of lobster red.

Or spy on the Soviet Union. Your choice. 

Anyway, with that preamble out of the way, do you want to know how to make a single-crystal blade? Of course you do! Here we go…

3: Production Perfection: Casting crystals.

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Tune in next week when I fill my bomb shelter full of canned goods and preserved seeds! No, not really.

Did you think this was going to be an article about Iran and war? It’s not. It’s going to be an article about nonsense; specifically, the nonsense in our heads that we all agree is real. Like company shares, kings, and the value of gold.

This morning my daughter, who is only four and therefore hasn’t got all the grown-up filters fully installed, showed me her princess tiara, which was made out of shiny metallic plastic with inset blue plastic “special gems”. She said it had special powers, and that she wouldn’t tell me what they were, except that those powers come to life in woodland.

OK…

Anyway, cue a very serious but slightly odd conversation about princess tiaras. It seems one of the other kids in preschool is a bit of a meanie and told her that she couldn’t be a princess, because there was already a princess and it wasn’t her. This obviously made my daughter quite upset. My wife and I were quite emphatic in telling her that, no, nobody else gets to decide if she’s a princess! She can be a princess if she wants to be!

Which is a very good parental lesson, while obviously being factually wrong in every respect, because I’m not a king.

But what’s a king anyway? It’s only a bloke who everyone agrees is the king, which means he has to be kingly because they believe he is. It’s not a material description: There’s not a single atom of Kingium anywhere in the universe, and certainly not in King Charles. But he’s still the King, even though it’s all a bit makey-uppy.

And during playtime, my daughter is a princess. That’s how it works. No special tiara with blue sparkle-gems required… although I really do want to know what its special woodland power is.

So much of what we take seriously is basically made-up nonsense, when all is said and done. The shares I have in various companies are just records in a computer somewhere, their value is just what an average shlub is prepared to pay for them to get my imaginary computer titles, and it’s paid for in imagination money, to buy more imagination products, like insurance or bitcoin. 

Actually I don’t own any bitcoin, because I’m not totally divorced from reality; just divorced enough to be normally human. That’s why at home I play imagination king to my daughter’s imagination princess and drink imagination tea and have imagination cakes and nibbles. It’s all very macho.

But everything is that way, isn’t it? The money we spend has value because we play a big imagination game and all try to guess the same answer. Our laws are imagination games (especially the silly ones like taxation, or the types of windows allowed on the second story of a house), our companies are imagination games and our gods, kings and presidents are imagination-people. That’s why we can say things like “Donald Trump closed the Strait of Hormuz!” and really mean it, as if a mile-high orange man with a bad hairdo had actually waded out into the Strait to bat away incoming tankers.

Obviously he didn’t, but wasn’t it fun reading that and imagining a mile-high Donald? 

No, Trump didn’t pick up an oil tanker and hurl it onto a mountaintop with a roar of victory. He just waggled his lips at people, who waggled their lips at other people, until somewhere down the line the people doing the lip-waggling were in charge of big ships, that put a hundred thousand tons of steel in menacing places. It’s an imagination game, but with a really big princess tiara.

Leading people is the same thing. As the Alpha Chimp you get special privileges; a big salary, first choice of fancy food and the ability to boss people around, and in return you have to make decisions for people so they don’t have to. It’s another imagination game, but one where people get to rent space inside your head for a while: I’ll make you leader if you let my brain rest. Thanks!

None of us have had to leg it from sabre-toothed lions anytime recently, and none of us have scavenged for food in prickly bushes or tracked big game with sharpened sticks to feed our family, so what we mostly live in is a world of our own imagining. No wonder this shiny little box is so alluring; a smartphone is a natural next step for a species that believes in kings, God and gold. It lets you live somewhere else for a while. 

But reality finds us eventually. At some point the turbines need to spin, the fuel needs to burn, milk needs delivering and houses need heating, so we turn bitterly back to the world of the real.

And we’re slightly glad of it when we do.

I moved that pallet of coal to the fuel shed. It took quite a while, but I smiled when I did it, because while money disappears in the night, and kings come & go, coal will always remain coal. 

And if you’re running out of ideas, you can always burn it.

There is a kind of industrial magic that is almost lost to the ages, because we barely need it anymore: This is the exacting science of how to create oil, gas and petrochemicals and cheat nature with industrial chemistry. It’s a science that signposts our greatest visions of the future, and propped up the most odious regimes of the past. 

If you’re of a thoughtful frame of mind you might have watched the endless World War II programs that make up every history channel with a question in your mind: Amidst the grinding Panzers and screaming Stukas, where black & white images distil & dramatize the worst conflict in history, where did the Germans get all their damned oil? 

They certainly needed it, because tanks don’t run on happy feelings and you can’t fuel bombers with an IOU. You also need hydrogen to make ammonia for fertilizer and explosives, and Germany didn’t have huge amounts of natural gas that could be converted to that either. How did the world’s most evil empire keep going as long as it did?

Romania helped, and the Soviet Union exported oil before the war and had it stolen during, but after 1943, when the allies struck the former and the Red Army started pushing back on the latter, why didn’t Germany collapse like a house of cards, un-fuelled and un-lubricated? 

The answer lies in a mucky miracle of industrial chemistry that we should be mindful of, now that another distant war has cut off a fifth of the world’s oil supply and a third of its fertilizer. We could choose to ignore it, here in the developed world, secure and smug in our ability to out-bid everyone else for scarce imports, but that just moves the problem elsewhere. It also might not work next time. 

Whether by pragmatism or Just Stop Oil idealism, it would be wise to find an alternative source of the arterial blood of civilization. One that didn’t ooze from the crushed remains of ancient plants, but sprang from the creative heart of humanity. It would be wise if we re-learned how to make oil again, just in case. 

Like the NAZIs, except nicer.

There are several ways to do it, some cleaner and less stained by history than others, so let’s explore the Pragmatist’s Guide for making your own oil. 

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1: Why on earth would we do this?

I know, I know. We’ve been told time and again that all that oil and gas should stay in the ground, and the climate is in danger of teeter-tottering over a precipice. I’m no expert and I’m not about to disagree with the predictions of doom-by-weather, but I do think that we’ve got some of the incentives all arse-backwards. 

Human beings need energy, and that’s all there is to it. It’s very noble and well-meaning to say, as some do, that we should reduce our energy consumption and our impact on the world, but the trouble is that you can only do so much: If you want to reduce pollution by reducing consumption, then this logically trends towards zero, leaving you scratching a living eating bugs in a hempen tent before being finished off by winter. Not ideal. 

We could electrify, of course, and thereby keep our energy use high but clean. This does, however, leave out a few things: Firstly, not all fuels are replaceable by the spark, such as aviation or specialist mining vehicles, or ships. Secondly, our pharmaceutical system, fertilizers and entire food chain is entwined with petrochemicals, and we can’t easily remove them without starving ourselves. 

Thirdly, of course, we might be in a nation under blockade, or simply fall over the tripwires of geopolitical happenstance, as war in a heat-blasted foreign place or strategic chokepoint renders entire nations suddenly, embarrassingly, without the black stuff.

Or you may just want to invade Taiwan. Or Poland. 

In all cases there’s a need to synthesize petrochemicals, whether it’s a noble endeavour like Rivan, a synthetic fuels company that’s about to convert solar energy, water and captured CO2 to usable methane in the UK, or something more nakedly commercial, like ultra-pure specialty fuels.

Or, just perhaps, you might be on the bad side of history, and need a helping hand from industrial chemistry, and coal…

2: Not Quite Fairy Dust.

In World War 2, Germany didn’t have much oil, but it did have some very good chemists and engineers, and that counts for a lot. It also had coal.

With coal and a little bit of effort & ingenuity you can pump the pulsing blood of global warfare. This is done with something called syngas, and something called the Fischer-Tropsch process.

Syngas is better known by two other monikers, ‘town gas’ and ‘coal gas’. It was what was often used to light lamps, heat homes and cook meals in the late 19^th and early 20^th centuries, before drilling and exploitation technology advanced sufficiently to make clean natural gas available to the masses. Syngas is a mixture of hydrogen and carbon monoxide, with some carbon dioxide, methane and other impurities for flavour, and you can immediately recognize that it’s altogether less pleasant than the methane we all know and love/ hate today. 

However syngas has a couple of useful properties, one of which is that you can synthesize it from coal, which unlike oil & natural gas is available in all sorts of places, particularly in oil-starved Europe and China. You make it using a process called ‘coal gasification’.

In coal gasification, milled coal is blown by oxygen and steam in a hot, high temperature environment, typically 800-1,000 Celsius and 20-100 atmospheres of pressure, though ranges outside this are possible. The oxygen supplied is at an insufficient level to allow for full combustion, and so the carbon in the coal reacts with the hydrogen and oxygen in the steam and gas flow to create syngas. The supply of oxygen helps balance the energy of the reaction, rendering it only slightly exothermic (producing net energy) by balancing the generation of carbon monoxide & hydrogen (endothermic) with the reaction of oxygen and carbon to make carbon dioxide (exothermic). 

Once you have syngas, this needs to be cleaned of carbon dioxide, waste water and sulphuric acid, among other things, before being passed into the Fischer-Tropsch reactor.

Fischer-Tropsch is a triumph of industrial chemistry developed by those clever Germans Franz Fischer and Hans Tropsch in 1926. It produces hydrocarbon fuel!

In Fischer-Tropsch, the carbon monoxide and hydrogen in the syngas is reacted in a lower temperature reaction (about 150-300 degrees) in the presence of a catalyst such as iron or cobalt, to form precious hydrocarbons and water. This can be done in a slurry tank with suspended catalysts, a fluidized bed reactor for high-temperature Fischer-Tropsch, or a tube-based FT reactor where solid catalyst is introduced to the reactants in tubes cooled by water. 

The ultimate output of Fischer-Tropsch is hydrocarbon chains with a carbon number of 10-20, which puts them in a perfect range for diesel and kerosene (aviation fuel) production. Handy, that. The reaction can be biased one way or another by tweaking temperature and pressure, and the output obviously needs a level of refining to separate the light stuff from the heavy stuff.

So: Fischer-Tropsch, or FT: Combined with coal gasification, it allows you to turn the black rocks into light synthetic oil, and therefore the basis for all kinds of stuff! All you need is coal and water.

And a cryogenic air separation unit, and a water-shift gas reactor, and acid removal, and a Fischer-Tropsch reactor, and hydrocarbon distillation, and waste management, and… it goes on a bit. This is not a cheap activity, and the economics of using coal to create synthetic fuels are dominated by capital spend. This is not a replacement for simply buying fuel on the global markets, unless something has gone badly wrong like, say, a blockade. Hence, Fischer-Tropsch is less an economic strategy than it is an insurance policy for civilizations.

A more efficient alternative is the Bergius process, which skips a lot of the complexity of Fischer-Tropsch and simply introduces hydrogen to ground, dried coal and a little heavy oil in a catalytic reactor at between 400 and 500 degrees and an ungodly 200-700 atmospheres of pressure. It has the advantage of running more efficiently than Fischer-Tropsch, but in a tradeoff produces much lighter fuel fractions, more volatile gases and leans more towards gasoline than diesel or kerosene. Between the two coal-munching processes, Bergius is efficient while FT is flexible. Season to taste.

But coal is messy and we don’t want to power a nation on coal, do we? Yuck! That’s too mucky by half, and the connection with the NAZIs is a little bit on the nose. Irrational, I know, but there you are. 

Coal-to-liquids: An insurance policy for a nation, but not a clean or a cheap one. We can do better…

3: Water Into Wine.

Now let’s talk about something shiny clean!

A startup company, Rivan, is doing something a little bit special, and difficult, in the UK and intends to create Europe’s largest synthetic methane plant. It will not be using coal, or biomass or anything of the sort. 

It’ll use water.

Britain, like many developed world nations, has an interesting conflux of problems: It wants to reduce its carbon emissions, it’s increasingly dependent on imported natural gas at an ever-increasing market price and its plans for electrification are being stymied by huge grid connection backlogs, at precisely the same time that the loss of old-school thermal power plants and the rise of low inertia power sources like solar & wind render the grid increasingly unstable. 

That’s quite the pickle!

Rivan attempts to bridge this gap and forge a path as a zero-carbon synthetic fuel provider, using something called the Sabatier process, which combines hydrogen and carbon dioxide with a catalyst at 30 atmospheres and 300-400 degrees to produce methane gas, of the sort that you use to heat your home. That sounds straightforward enough, but the real fun comes with how you get the hydrogen and carbon dioxide. 

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The online fracas was triggered by a recent poll by the Institute of Economic Affairs, a think tank. It revealed that most Brits believed that the UK, if it were hypothetically a US state, would be perhaps the 7th richest in the Union. In reality it would be dead last at 51, behind even Mississippi. Cue the banjos.

Ouch!

Well, it's true, so let's not pretend it isn't. By averages, medians or the great state of Mississippi, the Americans get paid more. I work in US multinationals in Ireland so I get to see first hand the difference in cost rates and it's real, there's no point stressing about it: Either get a work visa or don't.

I'm also British, so I've seen both sides of the divide and know that comparing ourselves to America is silly, because it's on a completely different planet. But Germany, the Netherlands and Sweden, among many others, do more with what they have than us, so what gives?

Firstly, let's shoot down the obvious nonsense: British people aren't lacking in spirit or vigour, or animal instincts or innovation. It's not a nation of losers or a giant crab bucket of bitter malcontents… no more than anywhere else, anyway. There's probably an extra frisson of class-based snobbishness, but people are people everywhere and Brits are more of the same, so the country's underperformance isn't some kind of divine judgement on our character.

Secondly let's stop thinking about Britain as a monolith, because in reality it's two economies, not one. This island has other islands inside it, which outperform much of the world: London, Cambridge, Oxford and half a dozen others casually take in globally-leading research, finance, engineering and practically all of Formula 1. Then there's oil, jet engines, pharmaceuticals, fusion and AI. There's stuff going on in the UK that flies vanguard for the entire world.

But there's the other Britain, which I was born into (Scarborough, North Yorkshire, just so you know). This is the vast hinterland that spreads outside the islands of wealth and sees echoes of itself in the dingy flats and drawn faces of Britain's very successful, and deeply depressing, soap operas. This Britain is physically, and psychologically, separated from the rich Brits by choked under-invested transport infrastructure and abominably-priced housing.

And this disconnect is a big deal. Where I live in Ireland is also a slightly downtrodden rural town, but because Ireland is usefully small and square I can live out in the boondocks and still commute into a city full of multinational money. That's not the case for many places in the British hinterlands. Many places are just… stranded.

Thirdly, however, it's not all bad and it's not all about the money. Manchester may be a lot poorer than similarly-sized Dublin or Minneapolis but it's also a lot more vibrant and fun. There are a hundred reasons a Brit might want to stay put instead of shipping out to Boston: Culture, community, football or just not wanting your kids to get weird accents. All good reasons, but we're still not doing as well as we should be. What gives?

The gap between economies is certainly more infrastructural than culturally-driven, but if there really is a character distinction between Brits and Americans, it's well illustrated by TV soaps: There's no aspiration in British ones, no tanned, botox'd models, sunlit beaches or conspicuous wealth. We like to be poverty voyeurs and see stories from the downtrodden, the gritty and the miserable. Except for Made In Chelsea, I guess: Perhaps the younger generation are sick of the grime.

So let's face reality, fellow Brits. We're not the richest kids on the block or anywhere close to it: Our woodwork is decaying, our lawn is ragged, our car is old and we're keeping up appearances with fresh coats of paint. Nevermind comparing ourselves to the USA, because Poland will probably overtake us soon, in PPP terms at least. There's no point coping about it online, pretending that ‘Our NHS’ makes up for it or lambasting immigrants, because that won't help either.

What will?

Britain's already good at flashy stuff. It grows more unicorns than anywhere else in Europe, it has cutting edge science and technology, a gigantic financial centre and is getting more proficient at linking University R&D into the commercial sphere. It's got the stable rule of law and all the tricky bits sorted, but struggles with the basic stuff…

Britain doesn't build.

Decades of not building infrastructure or housing doesn't kill you immediately, but over the decades it paralyses a country, and that's what we're seeing. A discretionary over-centralised planning system whose prime commandment is “Thou Shalt Not!” squeezes private building just as much as endless legal challenges hamstring new national infrastructure.

And this saps energy and belief in what is possible by us regular folk.

I mean, come on: The last major reservoir in the UK was built in 1992, yet after 34 years and fifteen million extra people we prefer hosepipe bans to building more reservoirs. Doesn't that say it all? This is in the nation that discovered graphene, for crying out loud!

Just as bad, we're not alone. The same infrastructural constipation that is most bowel-twistingly acute in the United Kingdom is now rife all across the English speaking world, and making inroads into the European continent as well. It isn't writ in stone and it can, and should be reversed, or more countries will fall into the pit. Britain would very much like to be an example to the world, but not that kind of example.

Don't get me wrong: A lack of building and expensive infrastructure is not Britain's only problem, but it does exaggerate most of the existing ones. Abundant housing & electricity, plus a quick clean commute and new hospitals, would take the sting out of a lot of things. We don’t need to literally live in the Victorians’ shadow. That way we might stop losing our brightest & best to Heathrow Terminal 5.

The cult of ever-increasing house prices is, on these sceptered isles, nothing more than an acute case of under-building. This is reversible: We didn't forget how to stack bricks.

And the moral of this story? We've got the hard bits right but the basics wrong. That's not the worst position to be in, because it means it's fixable. Our future can still be built.

On the one hand, the only thing standing in our way is ourselves.

But on the other hand, we've only got ourselves to blame.

A box wing and two small pusher propellors gives the game away: This is no ordinary chopper, but something odd that’s only been tried a few times in history, usually ending in embarrassment. It's a compound rotorcraft.

This is the RACER: Part helicopter, part plane and all odd, it’s a ninja-quiet, super-fast cruiser that sips fuel and pulls hard manoeuvres, all while keeping the ability to land important people on rooftops & hills. Or cardiac victims, injured mountaineers or soldiers, depending on how you use it. 

But the Racer plays tricks on you. The compound helicopter may look like someone bolted wings and propellors onto a chopper in a Scrapheap Challenge-style bout of bodging, crossed their fingers and hoped for the best… but Racer is altogether more sophisticated than that, being the kind of genius engineering compromise that just might revolutionize vertical flight. It’s exactly what you’d expect from its maker, Airbus: A sort of super-slick compromise that bores you while it excites you.

It's also precisely the kind of thing we want to see out of Europe, a continent which has lost out, economically, spiritually and diplomatically to China and America in the last couple of decades and now stands awkwardly, unsure of itself, not quite daring to look the world in the eye.

What are we for now? Are we a spent force, a museum continent, an exasperated release of breath? What can we still do well?

We can do a few things, one of which is definitely aviation!

So let’s dive deep into this racy rotorcraft, and ask what makes Racer so special, since this year it finishes its flight test program. Is it just a chopper with wings, or a subtle miracle? 

And why would you want a compound helicopter anyway? Let’s find out!

1: The search for speed. Compound rotors & historical mistakes.

Not just a rich boy's toy…

Helicopters have a bit of an image problem. Maybe it's all those Vietnam movies; it's hard to have sympathy for anyone leaning out of a sliding door with a machinegun, cutting down natives. Or maybe that's just Stanley Kubrick.

Either way, helicopters don't always inspire warm feelings in us. We tend to think ‘fatcat’, ‘police’ or ‘army’, and it's the first one that attracts the most ire. This is completely unfair. I remember as a boy the dull whalloping sound of the big yellow Sea Kings as they crossed the Scarborough cliffs and cruised out to sea with all the grace of a sick goose. They were lifesavers, and that's the other thing that helicopters can be: Search and rescue, hospital transfers and last-minute heroes. They can also just be taxis, blockish air Übers dropping off oil rig workers over vicious seas, continuing their vital work of keeping the lights on.

Helicopters are crucial… but could they be faster? The compound rotorcraft says “Yes!”

Adding a wing and a prop to a helicopter isn’t brand new, and those enterprising Americans had done it a whole bunch back in the 60s before giving it up as a bad idea, along with flared trousers, poofy hair and wars in South-East Asia. 

Some of them even had jet engines!

The principle behind it is simple. When a helicopter is flying forwards, the velocity of the air over the aircraft means that one of the rotors (the advancing one) is seeing a much higher airspeed than the other (the retreating one). As you keep flying faster and faster, this difference increases until eventually it reaches the point at which the retreating rotor starts to stall and the aircraft can’t fly anymore. That’s unfortunate.

However, early on it was realised that you can cheat aerodynamics, just a little, if you try to fly with something other than a rotating rotor blade. If you add lifting wings to the chopper, that generate proper lift at high speeds, and a propellor (or jet engine, if you’re crazy) then you can start being a little less whirlybird and a little more aeroplane, which means you can de-load the main rotor, delay the loss of controllable flight and go really, really fast! It also lets you fly more efficiently, and quietly, which is always a plus in these litigious, climate-conscious times. In a society where young adults are happy to walk around with gigantic headphones over their ears all day (seriously, what’s that about?), you probably can’t get away with being too noisy. And helicopters are bloody noisy. 

So: High speed, efficiency and silence. Sounds good. Why isn’t it already everywhere?

Well, it was tried. In the 1960s, Lockheed produced the AH-56 Cheyenne fast attack helicopter, with a high-speed dash capability of over 200 knots, a single pusher prop at the back and a pair of sizeable lifting wings. The design was such that the fixed wings would de-load the main rotor in a fast cruise, allowing for higher efficiency and a higher speed envelope: During fast flight, the main rotor would produce only 20% of the required lift of the aircraft, the remainder being supplied by the fixed wing, turning the Cheyenne into something resembling a conventional aeroplane. 

And a conventional aeroplane is quick!

It was still a helicopter, however, and the single fixed axis pusher prop at the back did nothing to counteract the torque of the main rotors, which needed cancelling with a conventional side-mounted tail rotor. This design choice led to a busy back-end!

The Cheyenne’s pusher prop allowed it novel abilities above & beyond mere speed. Because it could accelerate and decelerate laterally without inclining the main rotor, it had the ability to maintain a hover in high crosswinds and could even ‘bow’ to airshow crowds. It’s interesting to speculate what other manoeuvres this opens up that are denied to regular rotorcraft. Between this, the speed and other novelties such as a gunner’s seat that rotated in-line with the gun position and targeted with a helmet mounted sight, Lockheed’s offering had a lot going for it. 

Alas, the Cheyenne was not to be, and the program ended with the ten prototypes. The technical difficulties and complexity of the system, combined with a heavy sprinkling of politics, terminated the program and we ended up with the blockish gang of uglies we know today: Especially the AH-64 Apache that replaced this generation of heli gunships, so renowned for its graceful good looks and buoyant charm…

Or not. Blockish brutality it is.

Anyway, the fall of the Cheyenne marked the start of a drought of compound rotor designs. There was the odd concept, but the field stayed mostly dry until recently when a couple of new designs suddenly popped up. One was the Boeing-Sikorsky SB-1 Defiant, which in 2019 flew to compete for America’s Future Long-Range Assault Aircraft program. It certainly looked the part, seeming ready to mount an invasion of Mount Olympus and steal lightning from Zeus. The Defiant was itself based on an earlier experimental design, the Sikorsky X-2, which first flew way back in 2008.

And in-between was a European contender, the Airbus X-3 experimental compound rotor, a twin-prop powerhouse that broke an unofficial world speed record for helicopters in 2013 when it reached 255 knots in level flight. At this point, you’d think things were looking up for compound rotors. The drought was surely over, right?

Not so much. The Defiant, a daring design by any account, was beaten to the punch by a tilt-rotor design, the V-280 Valor. This resembles a conventional aeroplane with gigantic propellors that turn into rotors for vertical flight, on the ends of engine pods that can tilt from horizontal to vertical. The United States is fond of tilt-rotors, the quicker but madly complicated alternative to compound rotor craft, so this is a disappointment.

In Europe, however, the speedy X-3 eventually gave way to something new: A slicker and more well-optimized design that we now know as the Racer, a bucket of clever features with a much friendlier look than its American counterparts, more civvie-street than GI-Joe. It doesn’t look like it could invade Mars, but it could be a space-age air ambulance instead.

The Racer is amazing, and we’ll get onto it shortly, but first it’s worth discussing why compound rotors tend to fall at the first hurdle: Why, time and time again they are beaten to the punch, either by tilt-rotor specialists or ordinary helicopters.

Will the Racer lose the race to something much more basic?

2: Jack Of All Trades…

Pity the poor compound helicopter.

It’s neither one nor the other, neither racehorse nor mule. In theory the compound rotor occupies a glorious compromise-zone, more capable, quiet, long-legged and speedy than regular helicopters but also cheaper and simpler than the engineering Fabergé egg that is the tilt-rotor aircraft. Common sense tells us that it should therefore be wildly popular, and yet it isn’t. 

For the man looking to commute to work on an oil rig, where speed is secondary to stolid reliability, a compound velocity-machine holds no wonder. And for the US Marine Corps, which wants to drop tooled-up killers anywhere, anytime, as fast as possible, they’re happy to pay extra for something with a little more zip. 

And so the compound rotor is left high & dry, too sensible to be a star and too pretentious to ply a simple trade. We’re creatures of vigour and whimsy, us hairless apes, and we like a direction to be nice & clear. Compromises are a little too foggy and soft for us, a little too diplomatic, a little European for our tastes. So it figures that only Airbus wants to take it further.

The challenge of the compound rotor is a serious one: To appeal to anyone in particular it needs to be all things to all men, no longer a jack of all trades but a master of many, and it might just be capable of it. 

In the low speed regime it needs to be able to manage the missions that make up most of a helicopter's calling, without trading-off efficiency and handling. -And for the high speed missions it needs to keep up with tiltrotors for efficiency, silence and speed. It’ll never quite match it, but near enough might be just enough.

And it needs to do it for cheap, which means that any extra expense arising from its mechanical complexity needs to be paid for by fuel efficiency or the ability to do more, faster. 

That’s a tall order. Has the Racer managed it?

3: Novel Wings and Clever Things.

Before we start nerding-out on the features of this clever chopper, we should probably guess whether it’s even possible to be a master of both domains: Can you have the bonus without the grind, the soup without the spill? For the Racer, the two questions this devolves into are as follows:

1. Is it at least as agile in the low-speed regime as a conventional helicopter, and doesn’t compromise on payload, shape or price?

2. Can it keep up with the raw speed and payload capacity of a tiltrotor aircraft, but at a more affordable price point?

Well, is it?

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You may laugh, but I think that with a passing technological wind and the right incentives we could burst upon the solar system like an exploding dandelion seed, bringing life & mind to a dull, dead heaven… and that this time might be near.

Fanciful? You bet! 

But perhaps not as much as you think, so here's my optimistic screed on unlocking absurd sci-fi futurism.

And the big clue is that it involves something right overhead, that a group of astronauts returned from just the other day. The moon.

Artemis II was many things: A beacon of hope, a statement on the unity of mankind, an American national triumph, a practice run, a theatrical set-piece, the spear-tip of a vast bloated bureaucracy. All true, but what it also is, unavoidably, is a lesson in kinetic energy and the Tsiolkowsky rocket equation.

1: Inconvenient ratios & the fulcrum of giants.

The Artemis II crew module, finishing its historic journey, re-entered the atmosphere at a little under twenty five thousand miles per hour and touched town, somewhat slower, into a calm Pacific Ocean off the Californian coast. That ended a journey where some of the haunting photos returned from deep space contained in-frame  just about everyone who has ever lived. One beautiful rock, alone in heaven.

Wouldn't it be nice if we eventually spread so far and so wide that a single photograph could never encompass us all? That'd be a feat worth trying! A tricky one, though.

Part of the trickiness is evident looking at that little capsule bobbing in the Pacific. The Artemis II crew module weighs about nine tons, making it cramped but a lot roomier than the Apollo capsules half a century ago.

Yet this nine ton return capsule was carried into space by a launch stack that left Florida weighing over two and a half thousand tons! That's quite the difference, and that absurd mass and energy ratio might make interplanetary dreams look naïve, even deluded.

Or maybe, here's a thought, we just need a little more imagination…

Zoom out a little, look up from your phone for a minute or two and what do you see? It might be your lounge, or the illuminated darkness of a sleepless bedroom (in which case, put the phone away!), or a sunlit back road where your dog is sharing a blustery walk, or an office, or a factory. Hopefully you're not looking at the driver's wheel of your car.

In most cases what you will see is evidence of an energy-rich civilization where people raise buildings and travel long distances without a thought but -and this is the critical bit!- not by the strength of their own hands!

We have achieved greatness by becoming a fulcrum balancing huge forces; pulling in the churning energies of nature, dumping entropy and aiming the spare change at whatever glorious enterprise we desire. So, when thinking of flying to other worlds and conquering the infinite, this is how we should see ourselves: As a fulcrum point, carefully balancing the weight of dumb giants with a finger-press of force and intelligence.

How small can we make the fulcrum, and how massive the see-saw?

You quickly get to limits: A massive beast like the SpaceX Starship and Superheavy booster, if ever made fully and rapidly reusable, would amortise their human touch over many launches and only worry about the provision of liquid oxygen and methane, substances where large-scale process industries limit the consumption of that most precious commodity, human time. But even this, by its sheer size, has too heavy a hand on the giant's see-saw.

A full stack of Starship plus Superheavy carries an astronomical 4,500 - 5,000 tons of propellant to deliver up to 150 tons to low Earth orbit. Try to use the same vessel to get a hundred tons to the moon and, provided you want to re-use all your spacecraft, you end up with sixteen launches, mostly tankers, burning five thousands tons of propellant each. That's between seventy two and eighty thousand tons of propellant to get a hundred tons to the lunar surface. That's still better than throwing away an entire disposable rocket, but there's too much human involvement in that oxygen & methane propellant supply chain. We'll never colonise space that way.

So, what can we do?

2: Minimum thresholds and human cannonballs 

Well, first let's consider the lower limit of the energy equation: You need about ten kilometres per second of velocity to reach low Earth orbit, another three and a half kilometres per second to transfer to Mars and another ten on top of that if your goal is to find yourself in the cool embrace of Jupiter. Basically, if you can find twenty-four kilometres per second of velocity change, or ‘delta V’ then you can get to almost everywhere that matters.

How much energy, at the absolute minimum, is needed to do that?

Kinetic energy is 0.5 multiplied by mass (kg) multiplied by the square of velocity (metres/ second), so if you wanted to catapult an eighty kilogram human being to twenty four kilometres per second you'd need twenty three billion Joules. That sounds like a lot.

It is, and isn't. It's the amount of electrical energy generated by a AP1000 nuclear reactor in twenty three seconds, or the same as the chemical energy in forty six thousand cans of coca cola. Conveniently, it takes the Coca Cola company about thirty seconds to sell that much globally, so there's our minimum energy budget in two forms for a trip to Jupiter, each supplied in half a minute.

Not really, of course. You can't just shoot a human being to Jupiter. For a start, while you could put someone on a crash couch in an airtight pod in a linear accelerator tube full of vacuum and get them to 24km/s, it'd need to be big tube: Even for a very uncomfortable acceleration of ten gravities for the poor schmuck inside, you'd need to keep doing it for three whole minutes along a track 2,880 kilometres long!

And that three minutes of hell in an economy-sinking giant accelerator gun would only be the start of their problems, for wherever they emerged on Earth it'd be in atmosphere, meaning that they'd be instantly and painlessly vapourised.

So we're back to rockets again, except the problem with rockets is that they're not just accelerating a person, or a person in a capsule, but also the fuel needed to accelerate it, and the fuel needed to accelerate the fuel, and the fuel needed to… you get the picture. Because a rocket has to carry all its own propellant, you end up in an exponential growth scenario where to change your velocity any serious amount you need a ridiculously colossal rocket to move a teeny-tiny payload. Hence Artemis II.

We need to be more imaginative!

Human beings aren't all that big or heavy, but we have a lot of stuff. We're out-massed hysterically, hundreds or thousands to one, by our creations: Our cities, factories, roads and warehouses, all the dull firmament of civilization, and it's too damned heavy for us to carry it all to the stars.

So we need to build the stuff up there, not down here!

Picture a gun on the moon, a giant electromagnetic mass driver capable of throwing stuff, not human beings, to 4km/s or so. That's enough to put something in a solar orbit, a little closer in than Venus.

Why inside the orbit of Venus? Because it means intense sunlight for solar panels, but not so much heat as to demand exotic metallurgy. The need for this will become obvious soon.

And what would we send? The most valuable things we have! Power (solar panels), intelligence (AI chips), some xenon or argon (for thrust control) and power transmission & communication (lasers or masers). The goal is endless power transmission and propulsion capacity that can be beamed across the solar system: The seedstock of an industrialised solar system and infinite growth into space!

3: Infinite power arrays and senile gods.

To get the required beam coherence across the vast distances of the solar system, a single laser won't do, so you'll need active phased arrays of thousands of generators, orbiting a little closer to the sun than Venus. This uses frequency interference to within a fraction of a wavelength to create finely controlled tight beams of radiation from hundreds or thousands of well-coordinated emitters. It's the same principle used in ballistic missile warning arrays or the latest fighter plane radars… Except here the emitters could be miles apart, using far smaller wavelengths and coordinating to even tighter beamline control.

Oh, and because orbital mechanics is what it is, each laser power flock will be constantly moving and morphing as well. That's why you'd want your power array to be intelligent and arranged into tight ‘flocks’ rather than evenly spread around their orbit.

But the result? Infinite beamed power wherever you want it and the ability to cheat the Tsiolkowsky rocket equation, sailing on beams of radiation instead of burning fuel: The stuff of science-fiction fantasy, a solar civilization and spaceships tacking to winds of light.

And a swarm of flocking philosopher gods, casting power, propulsion and wisdom, the only remaining beings able to take a snapshot with all of humanity in it.

Not perfect ones, though. It's a distressing thought, but cosmic rays and other assorted deep space paraphernalia can damage CPUs over time, so our godlike solar hive minds, entrusted with doomsday rays and the arteries of civilization, might go a bit… senile.

We'll cross that bridge when we get to it, I guess.

But to cheat the rocket equation we must first make our super array and throw millions of laser stations into the hot spaces near the sun. Easier said than done if you're launching from Florida.

So: Moon mass driver!

4:Mass drivers and Von Neumann replicators 

If we're building and launching the power flock from the moon, we can use a solar-powered solution. And because we're launching machines, not squishy humans, we can turn up the acceleration: Make the electromagnetic gun shoot things at fifty gravities of acceleration and you can hit 4 km/s with ‘only’ a sixteen kilometre long track. On the moon.

Suddenly this sounds difficult again, especially since you'd need a lot more than one of these, to account for the slow rotation of the moon. Multiple sixteen kilometre accelerators and millions of power satellites cannot be subject to the rocket equation!

So they must be built on the moon, from materials mined on the moon, and because we can't ship a city there yet, this needs to be fully automated, self-maintaining and self-replicating.

Our finger on the fulcrum needs to disappear entirely!

Let's recap our list of sci-fi prerequisites, shall we? For this to work we need five technology clusters to mature:

1. Low cost orbital launch with rapidly re-usable rockets. Almost there.

2. Reliable agentic AI capable of running an industrial network, optimising a mining operation and controlling robots & laser arrays. Almost there!

3. High precision laser or maser coordination across vast arrays. Not too far off.

4. In-situ resource utilisation on other worlds: Barely tried and needs lots of work but we know it's possible because we do it here.

5. Fully automated self-replicating industrial units: Barely investigated and pointless on Earth, though it should be possible because, well, we do it now with human beings. 

All that, plus a staging post on the moon, unlocks the infinite future. Decades of work for sure, but I see no reason at all why this should be impossible. Lunar regolith has oxygen, silicon, aluminium, iron, calcium, magnesium and titanium plus some trace elements. The rarity of gallium and similar rare earths would lower achievable power conversion efficiencies, but for a bulk solar panel solution (the vast majority of launch mass) it'd be ‘good enough’. There's potential here.

It could be unpalatable, though. Do we have the will, and the vision?

We're a selfish short-term lot, us hairless apes. If there's a benefit to us doing a thing we'll go at it hammer & tongs but if it's a bit too abstract, or benefits someone we don't know then, meh, it can wait. We're cute like that. So what could make it in our interest to develop off world ISRU or self-replicating factory technology? You wouldn’t need everything, just enough for low grade solar panels, electronics and hall thrusters: We could probably ship the AI chips and advanced optics from Earth if needed.

To be frank, the only thing I can think of that would make us raise our monkey digits and solve this is if we already had people living on another world. A base won't do. A flag won't do! Laboratory studies in a stuffy university basement won't do! 

We need skin in the game.

If we never have people living, loving and working off-world then we'll never bother to develop self-replicating factory seeds, or solve the problem of mining on other worlds. Why would we? We've got a whole planet here full of cool stuff, with trees and funny monkeys too. 

That's the chicken-&-egg of space colonisation, and it's an absolute bastard.

We'll know what to do when we get there, but to get there we need to know what to do. Dang it.

One day we'll take that leap of faith, for all of us.

And for the senile gods.

P.S: This was meant to be a lot shorter, but there's a seed of an idea here. I glossed over the awesome difficulties of self-generating industrial systems and Von Neumann replicators (and the laser array!), but that's a subject that's worth a technical article in its own right. I will return to write that one!

The seconds roll into minutes, an appallingly short time for the joining of a big, complex assembly designed to hold the inside of a jet engine together in conditions that would soften steel. It's quick but it's done; the electron beam switches off and the cooling metal prepares to leave the vacuum.

I watched this on a camera, years ago in a Rolls-Royce factory, as the beam danced with inhuman agility and my only thought was “God, but it's fast!”

This is the awe & wonder of electron beam welding and the secret supply chain that furnishes us with the technological miracle that lets us fly around the world.

What God has joined together, let no man separate…

Let's learn about welding, shall we? 

1: Arc Light & Pipelines

Prudhoe Bay, on the North Coast of Alaska, is a frigid, isolated place. It's a land of caribou, aurora and, sometimes, the midnight sun.

And few people. A little over a thousand souls reside here which is not much, but still more than in the year 2000 census, which recorded five.

It's also the origin of a colossal engineering triumph called the Trans-Alaska Pipeline, which carries recently-discovered oil eight hundred miles south to the opposite coast of Alaska, and a connection to civilization. 

The pipeline, a creation of many thousands of people over three frenetic years, needed to be structurally perfect and leakproof across its entire length, operating in brutal temperature swings and cumulative distortions: Every year it grows and shrinks as summer lurches into vicious winter and falling temperatures shrink the metal. It was designed to cope with earthquakes, built in a zigzag pattern to absorb them. One hundred and eight thousand welds joined the entire pipeline!

And each of those one hundred and eight thousand welds was assessed to perfection through X-ray inspection. No leaks allowed!

This world is joined, brazed, fused and forged together. All of our greatest civilizational achievements depend on metal that is beaten, softened, roasted, squeezed and melted with lightning… and made stronger in the process. 

Welding is a science made art, a creative black magic gifted by the devil and used to make our world. We would be lost without it.

2: God of The Forge (and nuclear fuel).

Years ago, in a stifling hot workshop and donning heavy overalls, I watched a furnace open its doors to a roller conveyor. From inside a blank rectangle, orange with heat, came out, urged on by serious looking men with long metal rods into a roller mill. The great rollers gripped the metal object and, rudely, pulled it through and squeezed!

Out it came: A little thinner, a little longer, onto more roller conveyors in front of another waiting furnace. The serious men stopped it and approached, as angry yellow sparks spat from its surface. They measured its thickness at the corners with long callipers; a fast job with thick gloves and hot metal. Another man made a note and then they urged it onwards into the second furnace to sit for a few more hours. The whole process took less than a minute.

Inside the orange rectangle, cushioned in vacuum, an assembly of zirconium alloy and a small amount of highly enriched uranium was slowly joined together. Eventually the steel jacket would be removed and the freshly born nuclear fuel element would move on for further shaping & processing, to join hundreds more in the reactor core we were making.

We didn't know it at the time, but we were participating in something ancient.

Forge welding predates recorded history, and functions by heating metals to 50%-90% of their melting point, removing the oxides from their surface and exposing them to pressure, often by hammering them together. The two metals stay solid but plastically deform and diffusion bond together, the metal close to recrystallization temperature. The skilled Smith could influence this and the strength of the resultant join through temperature and technique.

Forge welding, and its modern equivalents in roller mills and hammer forges, can create structurally impressive joins but is constrained by the high skill required, and control over force, time and temperature. Blacksmiths were respected for a reason!

Some aspects of this sword-making, chain-linking ancient discipline cast light on what else is important in welding: For one, the need to remove oxides and keep them off. Oxides are formed when high temperature metals react with oxygen in the atmosphere, forming a chemically stable layer that can protect the metal, but that also contaminates further joins, creating weak spots. We don't want this.

In the era of the blacksmith, oxides were removed by flaking, and kept off by using charcoal forges that reduced local oxygen levels. In my Contact Shop, where the nuclear fuel elements started their journey, we were more sophisticated, encasing Zirconium in steel jackets and vacuuming out the air before hot rolling, but in all forms of joining you will see the need to control oxygen, nitrogen and other gases that could ruin your weld.

Another aspect to a weld is the ‘heat affected zone’, or HAZ. This is the volume of surrounding metal that is heated close to, or past the point of recrystallization. This is important because many of the mechanical characteristics of metals are influenced by crystal grain size, which can be changed by impact, heating and cooling. A weld can therefore have very different characteristics to its surrounding metal, possess odd defects and so the HAZ is best kept small. 

Different weld techniques are good at different things, which is why their variety covers hammering, rolling, arc welding, flame torches, beam welding and just rubbing stuff together really really hard! 

There is infinite variety in the black art of welding, so let's prize apart the mystery and take a look….

3: Building With Lightning! Arc welding.

One weld to rule them all…

The arc welder is so archetypal that the technology is taken completely for granted: Tinted visor, face coverings, thick gloves and spark-resistant clothing, the weld is flashed into being by a tiny star, bright enough to burn your eyes. The welder works behind sheet panels or dark curtains, and lighting flashes theatrically between the cracks. 

Behind those curtains, Creation is happening.

The principle behind it is simple enough: To join two metals, even dissimilar ones, you need to locally melt them and introduce a weld filler material that forms a liquid bead which solidifies behind the weld track and joins them. Easy to say, harder to do.

Carbon arc welding was developed way back in 1881 by Russian Nikolay Bernados and used high current electrical discharge between a carbon electrode and the workpiece to locally heat a tiny volume to typically 3,600 degrees, a temperature unattainable by any other means back then.

Arc welding is a form of ‘fusion’ welding, in that it melts a volume of metal, in contrast to ‘solid state’ methods such as forge welding or hot rolling above.

There are three main methods of arc welding in-play today. Yes, welding afficionados, I know I'm missing a few out but let's focus on the big ones: Shielded Metal Arc Welding (SMAW), Gas Metal Arc Welding (GMAW), and Gas Tungsten Arc Welding (GTAW).

We'll start with GTAW first, because it produces the highest quality welds, and because it has a friendly-sounding alternative acronym, TIG (Tungsten Inert Gas). 

In GTAW/ TIG, a non-consumable Tungsten electrode generates a direct current arc between itself and the workpiece, melting a small local weld pool. Filler material is then introduced by a separate weld filler wire, introduced off-axis, while oxidation of the weld is prevented by using an inert shielding gas, usually argon, which is blown continuously over the weld.

TIG is one of the most controllable forms of welding and is very good at shielding against oxidation, which leads to dependable quality and demand from such industries as aerospace and nuclear. TIG is used to weld together nuclear reactor pressure vessels; the pressure cooker that houses entire reactor cores. It's hard to think of a more critical task!

But it's not quick! It's more tortoise than hare and the welding of a nuclear reactor pressure vessel is an operation taking many months, due largely to slow speed (20cm - 80cm per minute), a small weld bead (5mm thickness or less) and the sheer volume to fill-in with such a heavy vessel.

That's grand for something as rare and majestic as a nuclear plant, but not much good for anything more agricultural or mass-produced.

By contrast, MIG (GMAW) is a lot faster. In this, there is no separate electrode, but the incoming filler wire becomes the electrode as it is extruded and is rapidly consumed. This makes it easier to learn and easier to automate than TIG, while also allowing resistive heating (current passing through the filler wire), which speeds things up tremendously.

But nothing is without cost. MIG may be quick and simple, but it's more prone to spatter than TIG and has less control of filler material input rates, so there is an inevitable quality tradeoff. If we stay with the nuclear RPV, for example, TIG makes the structural joins while MIG applies cladding layers to the inside of the vessel, typically corrosion resistant stainless steels.

Use the right tool for the right job!

Moving yet further down the quantity/ quality curve, stick welding (SMAW) doesn’t use inert shielding gas at all, but instead has a consumable electrode coated in flux, a substance which degrades into a shielding gas with heat. The flux also spits, spatters and deposits layers of slag on top of the weld, which needs cleaning off later. It’s a much messier process than either TIG or MIG.

But quick! The technique was adopted in World War 1 for shipbuilding & repair, requiring rapid, deep welds that could be applied in a wide variety of positions & conditions. It’s messy and slowed down by the need to remove slag, but aided by depth penetration on thick sections. Indeed, the Trans-Alaska oil pipeline that we mentioned earlier was mostly welded in-situ by stick-welding (though MIG welders formed the initial root weld between sections). This was largely due to the robustness of the method: The ability to weld without shield gas is useful in arctic conditions where piercing winds can blow away jets of argon and stop them from working. 

So there you go: The three major arc welding methods: Aristocratic TIG, user-friendly MIG and agricultural stick welding. Each of them charming the lightning to unite what was once broken.

But this is merely the beginning of our journey through the weld, for you don’t need lightning to join things, or even flame.

Sometimes, friction will do. For if you rub things together hard enough, strange things will happen…

4: Mocking momentum: Friction welding.

In 1995, Rolls-Royce had a problem. 

It was developing the EJ200 jet engine, a state of the art lightweight, high-thrust turbofan to power the new Eurofighter Typhoon. This was to be a showcase of cutting-edge European aerospace technology, a supersonic knife-fighter that could take on Ivan, teeth bared, over the continent and bring the bear to heel. In theory, anyway; the Soviet Union had disappeared, so the Typhoon would have to find other things to do for a while. 

The engine was something else, though, and contributed to a fighter plane with the fastest climb rate of anything else in service, with the possible exception of the exceptional (and exceptionally rare) American F/A-22 ‘Raptor’. Yet amidst all the glory of training such an athlete, Rolls-Royce had run smack into trouble. 

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“Christ, it's cold. Why didn't I buy an air to water system?”

But cheer up, it's Easter! And sometimes the worst doesn't happen.

Or Eostre, which is apparently what the pagans called it, back when it was about new life in general, not just the resurrection of Christ specifically... Or maybe Eostre was just some local Germanic custom; history's unsure about that.

Whatever. Chocolate eggs, bunnies and a long weekend. In all cases it's a generally upbeat time… Except in Ireland this year, when a storm called Dave has characteristically placed itself smack-bang in the middle of a three day weekend and cancelled all the kids’ easter egg hunts. Typical.

So let's do a bit of doomy-gloom before we rev up the springtime positivity, shall we?

On my regular commute I've noticed, under the wan sunlight of an uncertain Irish springtime, weird crystalline growths sprouting darkly on rooftops. It was rare at first, even worth remarking on, but as the weeks went by I noticed more and more, creeping over aged slate and replacing them with something black and glossy, like an alien growth, which is what it is: Outgrowths of our collective neuroses, made solid by fear.

They are of course solar panels, and I'll be getting my own this week. Sounds mundane I know, but these are fear's fruiting body, raised in the rich loam of the second energy crisis in four years in an already-expensive country.

It's also an outcropping of hope, that twinkles softly under directionless overcast in a land where the sun mostly hides. Please come out and shine. Give me energy that's mine. 

I like that instinct! In the last crisis people mostly sat down and took it, just as they did with Covid before then, waiting for a state-funded saviour. This time they're sick of waiting and are taking their fate into their own hands, with Chinese solar panels and a few tons of Polish coal. Action defeats depression, every time.

Action also prompts pragmatism and fights ideology, which is why I bought pallets of coal for the winter, in anticipation of limited oil stocks. Solar panels and dirty coal make for narrative conflict, but I'm not doing this for Johnny Polar Bear and neither are the families in other houses I see on my route.

Problem, meet solution.

The sky hasn't fallen yet, but we're primed to see threats. When my wedding day was coming we obsessed about the rain (it came anyway but we didn't care). We fretted about our unborn kids during every pregnancy (they were all OK, though one was dicey). I worried before every rugby match that I'd get flattened (I usually didn't) and we're anxious every time our kids seem off-colour (it's always OK, except for that one time it wasn't).

A little bit of action helps make the problems go away, so the end times never arrive. Of all the thousands of homeowners hurriedly installing solar panels this summer, many will be installing batteries as well, in their thousands. It doesn't take much of a leap of imagination to see an outcome where hundreds of thousands of household batteries have created overnight storage in the gigaWatt-hours, quietly shuffling energy from those blustery winter nights into crisp, still mornings. On such scales we'll still need natural gas, but not as much of it, and not because of state-funded saviours.

But because normal people did something to fix their own problems. 

Action annuls worry.

Easter is here and it's tempting, as we stretch out and relax, to gossip, watch a little too much news, doomscroll and fret that the Strait of Hormuz means that there won't be bread tomorrow. Or maybe there'll still be bread but you can't buy it because AI has taken the bread, your job and your girlfriend. Or something-something microplastics. Or fertility collapse, or something about the feminization of modern men, or… God, stop already!

Just give the kids a chocolate egg and watch them tear around on a toy car playing motorway unicorn ghostbusters. There, feel better now?

Last week the supermarkets ran out of eggs. Aargh! Panic! No fuel means no eggs, somehow. Quick, get them while you can! Never mind that six weeks of middle-East war couldn't possibly do anything to Irish egg laying. It still sounds scary, so people swarmed the supermarkets for eggs, just like they did with toilet paper during the Covid pandemic. I know, that didn't make sense either.

At the end of the day, the only shortage was one we created, by buying too many eggs all at once. The enemy was our own fear all along.

And for everything else, like heating oil or electricity… well, we can do something about that, can't we? More agency, less worry and we'll all get through OK.

And maybe the occasional exploration drill into the Irish Atlantic wouldn't go amiss either. Just sayin’.

So Happy Easter! And ignore Storm Dave, he'll go away.

There will be eggs tomorrow. Maybe even chocolate ones.

P.S: Yes, I know that there's a legitimate egg shortage situation and that Ireland is importing a lot of eggs, but it’s nothing to do with the business in Iran. Let’s not get all panicky.

Not quite. Not only is there a feast of innovation under the skin of our sky-bound servants, but there's a company out there making real mavericks, and it's sent one brand new, and often crazy, aircraft design into the sky every year for decades.

It's called Scaled Composites. It's circumnavigated the world, built giants, flown reusable spaceplanes and taken asymmetric-wing oddities to the sky.

And it's spent most of its life led by Burt Rutan, a mutton-chopped CEO and Chief Designer who looks like a Victorian time traveller sent to bring originality to aviation.

He's managed that handsomely.

What follows is a paean to the most inventive aerospace company you never heard of, and its signpost to the future of flight.

1: Oblique wings & the swingin’ sixties.

Before Scaled Composites even existed, there was the Rutan Aircraft Factory, founded by Burt Rutan, who was also chief designer & lead engineer. For some time he had churned out home-build kit aircraft of delightfully unconventional design, making heavy use of composite materials. 

This took a novel turn in the late seventies when Ames Industrial were contracted by NASA, and subcontracted Rutan’s team to design a unique experimental aircraft: The NASA AD-1.

The Oblique Wing. 

Let’s take a step back. The decade previous, the 1960s was swingin’ for a number of reasons, and one of the nerdier ones was the sudden profusion of variable geometry ‘swing-wing’ aircraft in airforces. The swing-wing concept was simple, though complicated to pull off: At low speeds and during takeoff & landing, an aircraft should ideally have a modestly-swept but high span wing (low length, high span width), like an albatross or seagull. This optimizes for high lift at low speeds and also reduces induced drag; a phenomenon dominated by vorticity at the wingtips. More on that later. 

By contrast, at transonic and supersonic speeds, and aircraft should have its wings swept back, because at such crazy-nuts speeds shockwaves will form on the leading edges, with their angle dependent on Mach number, the speed of the aircraft relative to the local speed of sound: The higher the Mach number, the tighter the ‘shock cone’ produced and so the more swept the wing should be for lowest possible drag. As a result of this, many aircraft were designed with variable geometry wings that could articulate back on sturdy rotary joints to let them fine-tune themselves for their conditions.

But back even as far as the second world war, an opportunity had been spotted by bold aerodynamicists to do one better, and create an oblique wing, which pivoted from a single mid-mounted joint in an asymmetric fashion. The images demonstrate this amply, and at first it makes no sense at all: How could something that weird fly and why on God’s green earth would you do it?

A few reasons. 

NASA engineer Robert T. Jones had investigated this concept in detail and realised something big; that an oblique wing could outperform conventional symmetric swept-back wings at supersonic speeds, with much lower wave drag. This takes a little explaining…

Wave drag is drag caused when air is squeezed by a supersonic aircraft that approaches too fast for air to step out of the way. This causes shockwaves to form, a draggy and wasteful physical phenomenon. Minimizing this can be done by adhering closely to something called the ‘area rule’: In short, imagine that you walk down the length of an aircraft and with every step you turn and cut it in half, before prizing it apart and admiring the cross-section. The area covered by this cross-section should change only slowly and gracefully as you move down the length of the aircraft, in a steady curved parabola up & down. No sudden steps or cliffs allowed! This is how you minimize wave drag when flying supersonic.

Now imaging a symmetric swept-back wing, which creates a sudden rise and drop in cross-sectional area. Getting around this is tricky and often requires awkward fuselage contours to fit the area rule (like the F-106's infamous ‘coke bottle’ fuselage). However if you just make the wing oblique, pivoting around the midpoint of the aircraft, then the profile of the wing will adopt a natural up & down curve, adhering to the area rule while remaining sharply-swept. That means minimal wave drag, a more cylindrical fuselage and even simpler mechanical systems compared to a conventional variable-geometry wing.

You just have to put up with a few stability effects and it looking weird as hell.

Rutan’s team designed the AD-1, which flew a limited flight test regime with NASA and proved out the concept. It was not taken further, in part due to the challenges of dynamic coupling in the roll & pitch axes, coupled with difficult to manage aeroelasticity problems, particularly on the forward-swept half of the wing. It was a brave and interesting attempt though, and opened Rutan up to a world of experimental aircraft. Scaled Composites would form soon after. 

And the AD-1 was only the beginning.

2: Starship.

In the eighties, the Beech Aircraft Corporation had a problem. It needed to replace its fabulously successful but long in the tooth King Air series of twin engined turboprops, and in doing so shake up the notoriously conservative general aviation market with something revolutionary. Something head and shoulders beyond the competition: An aircraft from the future.

Their project was the Starship.

The Beechcraft Starship is something from another world that you’ll have seen on the front covers of niche aviation magazines, if you're as weird as me. It was designed to create a step-change in general and business aviation, leaving aluminium behind and turning to carbon composites as a primary structural material. Super lightweight, rigid and exceptionally strong, composites are almost perfect for aviation, and indeed they’re everywhere now… but the eighties was almost too early to introduce these wonder materials, as manufacturing composite structures was still a morbidly expensive act of craftsmanship.

But someone has to be first, and it was to be the Starship! 

But Beech, and Scaled Composites which it had absorbed, was not satisfied with material changes alone, and Rutan’s team was given leeway for truly radical design. It needed to be quiet, comfy and capable of approaching 400 mph while retaining the classic fuel efficiency and short-field capability of traditional turboprop aircraft… and they delivered, but it didn't look normal. At all!

The main wing became rakishly swept-back near the root to assist in stall resistance and high incidence flight for short takeoff, which gave leeway for the rest of the design to become more efficiency-orientated. The propellors were rear mounted in a pusher configuration to maintain the cleanest possible airflow over the front of the aircraft and to reduce cabin noise. This configuration ruled out a tailplane, which drove a canard fore-plane configuration instead.

Well, that's one side of the story. Another is that pusher props and canards were taken as an entry condition of the design, driving compromises elsewhere, and the science-fiction sweep angle was as much to do with managing this than short-field performance. I'll let you draw your own conclusions.

Burt Rutan had explored canards before with kit planes and this was known territory for him, but for a business aircraft it was completely unique.

One of the less appealing aspects of pitch control on a standard aircraft is that the tailplane must often act in opposition to the main wing: A pitch-up motion requires that the tailplane push itself down, producing negative lift and sapping the aerodynamic efficiency of the aircraft. A canard foreplane, by contrast, can act in the direction of the pitching moment, a benefit to short-field performance. 

Another strange feature of the Starship was the lack of a central tailfin, which was a deliberate noise-reducing measure: A pusher-prop configuration places the props a little too close to the vertical fin for comfort, and pressure oscillations from the props can cause cabin vibrations that are amplified by the fin. Rutan’s team chose to remove it, replacing it with extended winglets on the end of the plane’s skinny main wing. In doing so, the function of vertical stabilizer and drag-reducing wingtip sail were combined, saving weight and improving efficiency even further; something that would have been impossible with a conventional configuration. 

Incidentally, if you want an explanation of how tailfins and canard fore planes stabilize an aircraft, check out the article linked below which goes into dizzying detail. 

As for the winglets themselves, the function of these are to weaken the vortices that curl-up at the ends of a wing from the interaction between high pressure under the wing and low pressure above. These vortices push the air between them downwards, which tilts the incoming airflow, creating  a component of lift that acts in opposition to the direction of aircraft flight; in short, drag. We want to reduce drag, and so a winglet, or wingtip sail, aims to weaken this vortex and reduce induced drag on the plane. Scaled Composite’s idea of combining this feature with a vertical tailfin was genius. 

And the aerodynamic sleight-of-hand didn’t end there, for the canards up at the front of the plane had another Weird Trick to play to trim the aircraft…

During takeoff or landing, the main wing needs to generate as much low speed lift as possible, even at the expense of efficiency, and so flaps are extended to change its profile and steepen the lift curve for the wing. This works, but it pushes the aerodynamic centre backwards. To make up for that, a tailplane or foreplane would usually need to apply elevators up or down to counteract the nose-down pitching moment caused by the flaps and stabilize the aircraft. Burt Rutan decided this was wasteful, and thought of another, slicker, way to do the same thing.

He just changed the canard’s angle of sweep, tilting the entire foreplane either forwards or backwards!

Yep, the swingin’ sixies were back… eighties style!

This is why the Starship in cruise shows off a sexy swept-back canard foreplane, but the very same Starship coming in for landing with its flaps extended will have its canards swept forwards against the airflow, like Dick Dastardly's moustache. It was unconventional as all hell, but that’s what the Starship was all about.

And that unconventionality didn’t end on the outside of the plane! Inside, traditional analogue dial gauges had been replaced entirely with an all-glass digital cockpit. This may seem de rigeur now, but at the time the approach was revolutionary, fusing important data streams and reducing pilot workload.

Alas, the Starship was not a commercial success. The new technologies proved difficult to certify, and the 85% composite body difficult to manufacture with the tools of the time. Put together, this delay increased cost to a level where Starship simply couldn't compete, and only 53 were ever built: A classic case of the future arriving before its time, and paying the price. Even the characteristic variable-sweep canards were contentious; sure, they added aerodynamic efficiency, but like all variable geometry systems they also add weight and it's not clear the trade was worth it.

Many other innovations introduced with the Starship would eventually become mainstream, but it would take decades. Being early costs!

Our next entry betrays a little bit more of this unconventional design instinct, and the willingness for Scaled Composites to flirt with the Weird.

3: The Mudfighter.

Military aircraft don’t need to look ‘normal’, so the designers can run off and exercise a little bit of imagination, though not usually as much as Burt Rutan.

The Model 151 ARES was to be a low-cost replacement to the venerable A-10 ‘Warthog’, the gruff and pig-ugly tank killing and close support specialist that has stubbornly refused to die for many decades now. Beloved by soldiers (who like the idea of friendly death orbiting nearby) but less so by the airforce (who don’t like flying a big slow target within range of every missile in the area), the A-10 has been a wart-faced poster-boy for countless years, particularly for its gun.

The A-10 was built around the gun, a terrifying seven-barrel 30mm rotary cannon bigger than a car, designed to rend open battletank armour like Christmas wrapping. As the Cold War drew to an unexpected close, Rutan’s team were tasked with designing a light, low-cost successor to the A-10, and created Model 151, dubbed the Mudfighter.

A high aspect ratio wing with twin-boom tailfins closely coupled to wide canards, the Mudfighter was effectively stall-proof, as the canard foreplanes were designed to stall before the main wing, lowering the nose automatically. This gave the aircraft that distinctive ‘Rutan’ design flair and looked suitably menacing to boot, but the real weirdness was the design of the gun and engine emplacement on this nimble fighter. 

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