Category Archives: materials

Instant buildings: Kinetic architecture

Revisiting an idea I raised in a blog in July last year. Even I think it was badly written so it’s worth a second shot.

Construction techniques are diverse and will get diverser. Just as we’re getting used to seeing robotic bricklaying and 3D printed walls, another technique is coming over the horizon that will build so fast I call it kinetic architecture. The structure will be built so quickly it can build a bridge from one side just by building upwards at an angle, and the structure will span the gap and meet the ground at the other side before gravity has a chance to collapse it.

The key to such architecture is electromagnetic propulsion, the same as on the Japanese bullet trains or the Hyperloop, using magnetic forces caused by electric currents to propel the next piece along the existing structure to the front end where it acts as part of the path for the next. Adding pieces quickly enough leads to structures that can follow elegant paths, as if the structure is a permanent trace of the path an object would have followed if it were catapulted into the air and falling due to gravity. It could be used for buildings, bridges, or simply art.

It will become possible thanks to new materials such as graphene and other carbon composites using nanotubes. Graphene combines extreme strength, hence lightness for a particular strength requirement, with extreme conductivity, allowing it to carry very high electric currents, and therefore able to generate high magnetic forces. It is a perfect material for kinetic architecture. Pieces would have graphene electromagnet circuitry printed on their surface. Suitable circuit design would mean that every extra piece falling into place becomes an extension to the magnetic railway transporting the next piece. Just as railroads may be laid out just in front of the train using pieces carried by the train, so pieces shot into the air provide a self-building path for other pieces to follow. A building skeleton could be erected in seconds. I mentioned in my original blog (about carbethium) that this could be used to create the sort of light bridges we see in Halo. A kinetic architecture skeleton would be shot across the divide and the filler pieces in between quickly transported into place along the skeleton and assembled.

See The electronic circuitry potential for graphene also allows for generating plasma or simply powering LEDs to give a nice glow just like the light bridges too.

Apart from clever circuit design, kinetic architecture also requires pieces that can interlock. The kinetic energy of the new piece arriving at the front edge would ideally be sufficient to rotate it into place, interlocking with previous front edge. 3d interlocking is tricky but additional circuitry can provide additional magnetic forces to rotate and translate pieces if kinetic energy alone isn’t enough. The key is that once interlocked, the top surface has to form a smooth continuous line with the previous one, so that pieces can move along smoothly. Hooks can catch an upcoming piece to make it rotate, with the hooks merging nicely with part of the new piece as it falls into place, making those hooks part of a now smooth surface and a new hook at the new front end. You’ll have to imagine it yourself, I can’t draw it. Obviously, pieces would need precision engineering because they’d need to fit precisely to give the required strength and fit.

Ideally, with sufficiently well-designed pieces, it should be possible to dismantle the structure by reversing the build process, unlocking each end piece in turn and transporting it back to base along the structure until no structure remains.

I can imagine such techniques being used at first for artistic creations, sculptures using beautiful parabolic arcs. But they could also be used for rapid assembly for emergency buildings, instant evacuation routes for tall buildings, or to make temporary bridges after an earthquake destroyed a permanent one. When a replacement has been made, the temporary one could be rolled back up and used elsewhere. Maybe it could become routine for making temporary structures that are needed quickly such as for pop concerts and festivals. One day it could become an everyday building technique. 


Mega-buildings could become cultural bubbles

My regular readers, both of them in fact, will know I am often concerned about the dangerous growth of social media bubbles. By mid-century, thanks to upcoming materials, some cities will have a few buildings over 1km tall, possibly 10km (and a spaceport or two up to 30km high). These would be major buildings, and could create a similar problem.

A 1km building could have 200 floors, and with 100m square floors, 200 hectares of space.  Assuming half is residential space and the other half is shops, offices or services, that equates to 20,000 luxury apartments (90 sq m each) or 40,000 basic flats. That means each such building could be equivalent to a small town, with maybe 50,000 inhabitants. A 10km high mega-building, with a larger 250m side, would have 60 times more space, housing up to 300,000 people and all they need day-to-day, essentially a city.

Construction could be interesting. My thoughts are that a 10km building could be extruded from the ground using high pressure 3D printing, rather than assembled with cranes. Each floor could be fully fitted out while it is still near ground level, its apartments sold and populated, even as the building grows upward. That keeps construction costs and cash flow manageable.

My concern is that although we will have the technology to build such buildings in the 2040s, I’m not aware of much discussion about how cultures would evolve in such places, at least not outside of sci-fi (like Judge Dredd or Blade Runner). I rather hope we wouldn’t just build them first and try to solve social problems later. We really ought to have some sort of plans to make them work.

In a 100m side building, entire floors or groups of floors would likely be allocated to particular functions – residential, shopping, restaurants, businesses etc. Grouping functions sensibly reduces the total travel needed. In larger buildings, it is easier to have local shops mixed with apartments for everyday essentials, with larger malls elsewhere.

People could live almost entirely in the building, rarely needing to leave, and many might well do just that, essentially becoming institutionalized. I think these buildings will feel very different from small towns. In small towns, people still travel a lot to other places, and a feeling of geographic isolation doesn’t emerge. In a huge tower block of similar population and facilities, I don’t think people would leave as often, and many will stay inside. All they need is close by and might soon feel safe and familiar, while the external world might seem more distant, scarier. Institutionalization might not take long, a month or two of becoming used to the convenience of staying nearby while watching news of horrors going on elsewhere. Once people stop the habit of leaving the building, it could become easier to find reasons not to leave it in future.

Power structures would soon evolve – local politics would happen, criminal gangs would emerge, people would soon learn of good and bad zones. It’s possible that people might become tribal, their building and their tribe competing for external resources and funding with tribes in other mega-buildings, and their might be conflict. Knowing they are physically detached, the same bravery to attack total strangers just because they hold different views might emerge that we see on social media today. There might be cyber-wars, drone wars, IoT wars between buildings.

I’m not claiming to be a social anthropologist. I have no real idea how these buildings will work and perhaps my fears are unjustified. But even I can see some potential problems just based on what we see today, magnified for the same reasons problems get magnified on social media. Feelings of safety and anonymity can lead to some very nasty tribal behaviors. Managing diversity of opinion among people moving in would be a significant challenge, maintaining it might be near impossible. With the sort of rapid polarization we’ve already seen today thanks to social media bubbles, physically contained communities would surely see those same forces magnified everyday.

Building a 10km mega-building will become feasible in the 2040s, and increased urban populations will make them an attractive option for planners. Managing them and making them work socially might be a much bigger challenge.



Colour changing cars, everyday objects and makeup shows how graphene can be used to make displays with each pixel changing colour according to mechanical deformation.

Meanwhile, Lexus have just created a car with a shell covered in LEDs so it can act as a massive display.

In 2014 I wrote about using polymer LED displays for future Minis so it’s nice to see another prediction come true.

Looking at the mechanical pixels though, it is clear that mechanical pixels could respond directly to sound, or to turbulence of passing air, plus other vibration that arises from motion on a road surface, or the engine. Car panel colours could change all the time powered by ambient energy. Coatings on any solid objects could follow, so people might have plenty of shimmering colours in their everyday environment. Could. Not sure I want it, but they could.

With sound as a control system, sound wave generators at the edges or underneath such surfaces could produce a wide variety of pleasing patterns. We could soon have furniture that does a good impression of being a cuttlefish.

I often get asked about smart makeup, on which I’ve often spoken since the late 90s. Thin film makeup displays could use this same tech. So er, we could have people with makeup pretending to be cuttlefish too. I think I’ll quit while I’m ahead.

Sky-lines – The Solar Powered Future of Air Travel

High altitude solar array to power IT and propel planes

High altitude solar array to power IT and propel planes

A zero carbon air travel solution. Well, most of the bits would be made of carbon materials, but it wouldn’t emit any CO2.

The pic says it all. A linear solar farm suspended in the high atmosphere to provide an IT platform for sensors, comms and other functions often accomplished by low orbit satellite. It would float up there thanks to being fixed to a graphene foam base layer that can be made lighter than helium (my previous invention, see which has since been prototyped and proven to be extremely resilient to high pressures too). Ideally, it would go all the way around the world, in various inclinations at different altitudes to provide routes to many places. Carbon materials are also incredibly strong so the line can be made as strong as can reasonably be required.

The flotation layer also supports a hypersonic linear induction motor that could provide direct propulsion to a hypersonic glider or to electric fans on a powered plane. Obviously this could also provide a means of making extremely low earth orbit satellites that continuously circumnavigate the ring.

I know you’re asking already how the planes get up there. There are a few solutions. Tethers could come all the way to ground level to airports, and electric engines would be used to get to height where the plane would pick up a sled-link.

Alternatively, stronger links to the ground would allow planes to be pulled up by sleds, though this would likely be less feasible.

Power levels? Well, the engines on a Boeing 777 generate about 8.25MW. A high altitude solar cell, above clouds could generate 300W per square metre. So a 777 equivalent plane needs 55km of panels if the line is just one metre wide. That means planes need to be at least that distance apart, but since that equates to around a minute, that is no barrier at all.

If you still doubt this, the Hyperloop was just a crazy idea a century ago too.

Carbethium, a better-than-scifi material

How to build one of these for real:


Halo light bridge, from

Or indeed one of these:



I recently tweeted that I had an idea how to make the glowy bridges and shields we’ve seen routinely in sci-fi games from Half Life to Destiny, the bridges that seem to appear in a second or two from nothing across a divide, yet are strong enough to drive tanks over, and able to vanish as quickly and completely when they are switched off. I woke today realizing that with a bit of work, that it could be the basis of a general purpose material to make the tanks too, and buildings and construction platforms, bridges, roads and driverless pod systems, personal shields and city defense domes, force fields, drones, planes and gliders, space elevator bases, clothes, sports tracks, robotics, and of course assorted weapons and weapon systems. The material would only appear as needed and could be fully programmable. It could even be used to render buildings from VR to real life in seconds, enabling at least some holodeck functionality. All of this is feasible by 2050.

Since it would be as ethereal as those Halo structures, I first wanted to call the material ethereum, but that name was already taken (for a 2014 block-chain programming platform, which I note could be used to build the smart ANTS network management system that Chris Winter and I developed in BT in 1993), and this new material would be a programmable construction platform so the names would conflict, and etherium is too close. Ethium might work, but it would be based on graphene and carbon nanotubes, and I am quite into carbon so I chose carbethium.

Ages ago I blogged about plasma as a 21st Century building material. I’m still not certain this is feasible, but it may be, and it doesn’t matter for the purposes of this blog anyway.

Around then I also blogged how to make free-floating battle drones and more recently how to make a Star Wars light-saber.

Carbethium would use some of the same principles but would add the enormous strength and high conductivity of graphene to provide the physical properties to make a proper construction material. The programmable matter bits and the instant build would use a combination of 3D interlocking plates, linear induction,  and magnetic wells. A plane such as a light bridge or a light shield would extend from a node in caterpillar track form with plates added as needed until the structure is complete. By reversing the build process, it could withdraw into the node. Bridges that only exist when they are needed would be good fun and we could have them by 2050 as well as the light shields and the light swords, and light tanks.

The last bit worries me. The ethics of carbethium are the typical mixture of enormous potential good and huge potential for abuse to bring death and destruction that we’re learning to expect of the future.

If we can make free-floating battle drones, tanks, robots, planes and rail-gun plasma weapons all appear within seconds, if we can build military bases and erect shield domes around them within seconds, then warfare moves into a new realm. Those countries that develop this stuff first will have a huge advantage, with the ability to send autonomous robotic armies to defeat enemies with little or no risk to their own people. If developed by a James Bond super-villain on a hidden island, it would even be the sort of thing that would enable a serious bid to take over the world.

But in the words of Professor Emmett Brown, “well, I figured, what the hell?”. 2050 values are not 2016 values. Our value set is already on a random walk, disconnected from any anchor, its future direction indicated by a combination of current momentum and a chaos engine linking to random utterances of arbitrary celebrities on social media. 2050 morality on many issues will be the inverse of today’s, just as today’s is on many issues the inverse of the 1970s’. Whatever you do or however politically correct you might think you are today, you will be an outcast before you get old:

We’re already fucked, carbethium just adds some style.

Graphene combines huge tensile strength with enormous electrical conductivity. A plate can be added to the edge of an existing plate and interlocked, I imagine in a hexagonal or triangular mesh. Plates can be designed in many diverse ways to interlock, so that rotating one engages with the next, and reversing the rotation unlocks them. Plates can be pushed to the forward edge by magnetic wells, using linear induction motors, using the graphene itself as the conductor to generate the magnetic field and the design of the structure of the graphene threads enabling the linear induction fields. That would likely require that the structure forms first out of graphene threads, then the gaps between filled by mesh, and plates added to that to make the structure finally solid. This would happen in thickness as well as width, to make a 3D structure, though a graphene bridge would only need to be dozens of atoms thick.

So a bridge made of graphene could start with a single thread, which could be shot across a gap at hundreds of meters per second. I explained how to make a Spiderman-style silk thrower to do just that in a previous blog:

The mesh and 3D build would all follow from that. In theory that could all happen in seconds, the supply of plates and the available power being the primary limiting factors.

Similarly, a shield or indeed any kind of plate could be made by extending carbon mesh out from the edge or center and infilling. We see that kind of technique used often in sci-fi to generate armor, from lost in Space to Iron Man.

The key components in carbetheum are 3D interlocking plate design and magnetic field design for the linear induction motors. Interlocking via rotation is fairly easy in 2D, any spiral will work, and the 3rd dimension is open to any building block manufacturer. 3D interlocking structures are very diverse and often innovative, and some would be more suited to particular applications than others. As for linear induction motors, a circuit is needed to produce the travelling magnetic well, but that circuit is made of the actual construction material. The front edge link between two wires creates a forward-facing magnetic field to propel the next plates and convey enough intertia to them to enable kinetic interlocks.

So it is feasible, and only needs some engineering. The main barrier is price and material quality. Graphene is still expensive to make, as are carbon nanotubes, so we won’t see bridges made of them just yet. The material quality so far is fine for small scale devices, but not yet for major civil engineering.

However, the field is developing extremely quickly because big companies and investors can clearly see the megabucks at the end of the rainbow. We will have almost certainly have large quantity production of high quality graphene for civil engineering by 2050.

This field will be fun. Anyone who plays computer games is already familiar with the idea. Light bridges and shields, or light swords would appear much as in games, but the material would likely  be graphene and nanotubes (or maybe the newfangled molybdenum equivalents). They would glow during construction with the plasma generated by the intense electric and magnetic fields, and the glow would be needed afterward to make these ultra-thin physical barriers clearly visible,but they might become highly transparent otherwise.

Assembling structures as they are needed and disassembling them just as easily will be very resource-friendly, though it is unlikely that carbon will be in short supply. We can just use some oil or coal to get more if needed, or process some CO2. The walls of a building could be grown from the ground up at hundreds of meters per second in theory, with floors growing almost as fast, though there should be little need to do so in practice, apart from pushing space vehicles up so high that they need little fuel to enter orbit. Nevertheless, growing a  building and then even growing the internal structures and even furniture is feasible, all using glowy carbetheum. Electronic soft fabrics, cushions and hard surfaces and support structures are all possible by combining carbon nanotubes and graphene and using the reconfigurable matter properties carbethium convents. So are visual interfaces, electronic windows, electronic wallpaper, electronic carpet, computers, storage, heating, lighting, energy storage and even solar power panels. So is all the comms and IoT and all the smart embdedded control systems you could ever want. So you’d use a computer with VR interface to design whatever kind of building and interior furniture decor you want, and then when you hit the big red button, it would appear in front of your eyes from the carbethium blocks you had delivered. You could also build robots using the same self-assembly approach.

If these structures can assemble fast enough, and I think they could, then a new form of kinetic architecture would appear. This would use the momentum of the construction material to drive the front edges of the surfaces, kinetic assembly allowing otherwise impossible and elaborate arches to be made.

A city transport infrastructure could be built entirely out of carbethium. The linear induction mats could grow along a road, connecting quickly to make a whole city grid. Circuit design allows the infrastructure to steer driverless pods wherever they need to go, and they could also be assembled as required using carbethium. No parking or storage is needed, as the pod would just melt away onto the surface when it isn’t needed.

I could go to town on military and terrorist applications, but more interesting is the use of the defense domes. When I was a kid, I imagined having a house with a defense dome over it. Lots of sci-fi has them now too. Domes have a strong appeal, even though they could also be used as prisons of course. A supply of carbetheum on the city edges could be used to grow a strong dome in minutes or even seconds, and there is no practical limit to how strong it could be. Even if lasers were used to penetrate it, the holes could fill in in real time, replacing material as fast as it is evaporated away.

Anyway, lots of fun. Today’s civil engineering projects like HS2 look more and more primitive by the day, as we finally start to see the true potential of genuinely 21st century construction materials. 2050 is not too early to expect widespread use of carbetheum. It won’t be called that – whoever commercializes it first will name it, or Google or MIT will claim to have just invented it in a decade or so, so my own name for it will be lost to personal history. But remember, you saw it here first.

Future sex, gender and design

This is a presentation I made for the Eindhoven Design Academy. It is mostly self-explanatory


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The future of vacuum cleaners

Dyson seems pretty good in vacuum cleaners and may well have tried this and found it doesn’t work, but then again, sometimes people in an industry can’t see the woods for the trees so who knows, there may be something in this:

Our new pet cat Jess, loves to pick up soft balls with a claw and throw them, and catch them again. Retractable claws are very effective.IMG_6689- Jess (2)

Jess the cat

At a smaller scale, velcro uses tiny little hooks to stick together, copying burs from nature.

Suppose you make a tiny little ball that has even tinier little retractable spines or even better, hooks. And suppose you make them by the trillion and make a powder that your vacuum cleaner attachment first sprinkles onto a carpet, then agitates furiously and quickly, and thus gets the hooks to stick to dirt, pull it off the surface and retract (so that the balls don’t stick to the carpet) and then you suck the whole lot into the machine. Since the balls have a certain defined specification, they are easy to separate from the dirt and dust and reuse again straight away. So you get superior cleaning. Some of the balls would be lost each time, and some would get sucked up next time, but overall you’d need to periodically top up the reservoir.

The current approach is to beat the hell out of the carpet fibers with a spinning brush and that works fine, but I think adding the active powder might be better because it gets right in among the dirt and drags it kicking and screaming off the fibers.

So, ball design. Firstly, it doesn’t need to be ball shaped at all, and secondly it doesn’t need spines really, just to be able to rapidly change its shape so it gets some sort of temporary traction on a dirt particle to knock it off. What we need here is any structure that expands and contracts or dramatically changes shape when a force is applied, ideally resonantly. Two or three particles connected by a tether would move back and forwards under an oscillating electrostatic, electrical or magnetic field or even an acoustic wave. There are billions of ways of doing that and some would be cheaper than others to manufacture in large quantity. Chemists are brilliant at designing custom molecules with particular shapes, and biology has done that with zillions of enzymes too. Our balls would be pretty small but more micro-tech than nano-tech or molecular tech.

The vacuum cleaner attachment would thus spray this stuff onto the carpet and start resonating it with an EM field or sound waves. The little particles would wildly thrash around doing their micro-cleaning, yanking dirt free, and then they would be sucked back into the cleaner to be used again. The cleaner head doesn’t even need to have a spinning brush, the only moving parts would be the powder, though having an agitating brush might help get them deeper into the fabric I guess.


Smart packaging: Acoustic sterilisation

I should have written this on the ides of March, but hey ho. I was discussing packaging this morning for an IoT event.

Imagine a bacterium sitting on a package on a supermarket shelf is called Julius Caesar. Now imagine Brutus coming along with a particularly sharp knife and stabbing him hundreds of times. That’s my idea, just scaled down a bit.


This started as a slight adaptation of an idea I developed for Dunlop a few years ago to make variable grip tires. (Still waiting for Dunlop to make those, so maybe some other tire company might pick up the idea).

The idea is very simple, to use tiny triangular structures embedded in the surface, and then pull the base of the triangle together, thereby pushing up the tip. My tire idea used electro-active polymers to do the pulling, and sharp carbon composites to do the grip bit, or in this antibacterial case, the sharp knife. Probably for packaging I’d use carbon nanotubes or similar as the sides with which to stab the bacteria, but engineers frequently come up with different nanostructure shapes so I’m pretty agnostic about material and shape. If it ruptures a bacterium, it will be good.

An easier to use alternative for widespread use in packaging would be to ditch the electro-active polymer and associated electronics, and instead to use a tuned acoustic wave to move the blades in and out of the surface. All that is needed to activate them is to put out that frequency of sound through a speaker system in the supermarket or factory. The sound needed would likely be ultrasonic, so it doesn’t irritate all the shoppers, and in any case, nano-structures will generally be associated with high frequencies.

So the packaging would include tiny structures that act as the dagger attached to a particular acoustic mass acting as Brutus, that would move when the appropriate resonant frequency is broadcast.

This technique doesn’t need any nasty chemicals, though it does need the nanostructures and sound and if they aren’t designed right, the nanostructures could be just as harmful. Anyway, that’s the basic idea.


Self-sterilizing surfaces & packaging


How to make a Star Wars light saber

A couple of years ago I explained how to make a free-floating combat drone: , like the ones in Halo or Mass Effect. They could realistically be made in the next couple of decades and are very likely to feature heavily in far future warfare, or indeed terrorism. I was chatting to a journalist this morning about light sabers, another sci-fi classic. They could also be made in the next few decades, using derivatives of the same principles. A prototype is feasible this side of 2050.

I’ll ignore the sci-fi wikis that explain how they are meant to work, which mostly approximate to fancy words for using magic or The Force and various fictional crystals. On the other hand, we still want something that will look and sound and behave like the light saber.

The handle bit is pretty obvious. It has to look good and contain a power source and either a powerful laser or plasma generator. The traditional problem with using a laser-based saber is that the saber is only meant to be a metre long but laser beams don’t generally stop until they hit something. Plasma on the other hand is difficult to contain and needs a lot of energy even when it isn’t being used to strike your opponent. A laser can be switched on and off and is therefore better. But we can have some nice glowy plasma too, just for fun.

The idea is pretty simple then. The blade would be made of graphene flakes coated with carbon nanotube electron pipes, suspended using the same technique I outlined in the blog above. These could easily be made to form a long cylinder and when you want the traditional Star Wars look, they would move about a bit, giving the nice shimmery blurry edge we all like so that the tube looks just right with blurry glowy edges. Anyway, with the electron pipe surface facing inwards, these flakes would generate the internal plasma and its nice glow. They would self-organize their cylinder continuously to follow the path of the saber. Easy-peasy. If they strike something, they would just re-organize themselves into the cylinder again once they are free.

For later models, a Katana shaped blade will obviously be preferred. As we know, all ultimate weapons end up looking like a Katana, so we might as well go straight to it, and have the traditional cylindrical light saber blade as an optional cosmetic envelope for show fights. The Katana is a universal physics result in all possible universes.

The hum could be generated by a speaker in the handle if you have absolutely no sense of style, but for everyone else, you could simply activate pulsed magnetic fields between the flakes so that they resonate at the required band to give your particular tone. Graphene flakes can be magnetized so again this is perfectly consistent with physics. You could download and customize hums from the cloud.

Now the fun bit. When the blade gets close to an object, such as your opponent’s arm, or your loaf of bread in need of being sliced, the capacitance of the outer flakes would change, and anyway, they could easily transmit infrared light in every direction and pick up reflections. It doesn’t really matter which method you pick to detect the right moment to activate the laser, the point is that this bit would be easy engineering and with lots of techniques to pick from, there could be a range of light sabers on offer. Importantly, at least a few techniques could work that don’t violate any physics. Next, some of those self-organizing graphene flakes would have reflective surface backings (metals bond well with graphene so this is also a doddle allowed by physics), and would therefore form a nice reflecting surface to deflect the laser beam at the object about to be struck. If a few flakes are vaporized, others would be right behind them to reflect the beam.

So just as the blade strikes the surface of the target, the powerful laser switches on and the beam is bounced off the reflecting flakes onto the target, vaporizing it and cauterizing the ends of the severed blood vessels to avoid unnecessary mess that might cause a risk of slipping. The shape of the beam depends on the locations and angles of the reflecting surface flakes, and they could be in pretty much any shape to create any shape of beam needed, which could be anything from a sharp knife to a single point, severing an arm or drilling a nice neat hole through the heart. Obviously, style dictates that the point of the saber is used for a narrow beam and the edge is used as a knife, also useful for cutting bread or making toast (the latter uses transverse laser deflection at lower aggregate power density to char rather than vaporize the bread particles, and toast is an option selectable by a dial on the handle).

What about fights? When two of these blades hit each other there would be a variety of possible effects. Again, it would come down to personal style. There is no need to have any feel at all, the beams could simple go through each other, but where’s the fun in that? Far better that the flakes also carry high electric currents so they could create a nice flurry of sparks and the magnetic interactions between the sabers could also be very powerful. Again, self organisation would allow circuits to form to carry the currents at the right locations to deflect or disrupt the opponent’s saber. A galactic treaty would be needed to ensure that everyone fights by the rules and doesn’t cheat by having an ethereal saber that just goes right through the other one without any nice show. War without glory is nothing, and there can be no glory without a strong emotional investment and physical struggle mediated by magnetic interactions in the sabers.

This saber would have a very nice glow in any color you like, but not have a solid blade, so would look and feel very like the Star Wars saber (when you just want to touch it, the lasers would not activate to slice your fingers off, provided you have read the safety instructions and have the safety lock engaged). The blade could also grow elegantly from the hilt when it is activated, over a second or so, it would not just suddenly appear at full length. We need an on/off button for that bit, but that could simply be emotion or thought recognition so it turns on when you concentrate on The Force, or just feel it.

The power supply could be a battery or graphene capacitor bank of a couple of containers of nice chemicals if you want to build it before we can harness The Force and magic crystals.

A light saber that looks, feels and behaves just like the ones on Star Wars is therefore entirely feasible, consistent with physics, and could be built before 2050. It might use different techniques than I have described, but if no better techniques are invented, we could still do it the way I describe above. One way or another, we will have light sabers.