Daily Archives: October 13, 2017

Quantum rack and pinion drive for interstellar travel

This idea from a few weeks back is actually a re-hash of ones that are already known, but that seems the norm for space stuff anyway, and it gives alternative modus operandi for one that NASA is playing with at the moment, so I’ll write it anyway. My brain has gotten rather fixated on space stuff of late, I blame Nick Colosimo who helped me develop the Pythagoras Sling. It’s still most definitely futurology so it belongs on my blog. You won’t see it in operation for a while.

A few railways use a rack and pinion mechanism to climb steep slopes. Usually they are trains that go up a mountainside, where presumably friction of a steel wheel on a steel rail isn’t enough to prevent slipping. Gears give much better traction. It seems to me that we could do that in space too. Imagine if such a train carries the track, lays it out in front of it, and then travels along it while getting the next piece ready. That’s the idea here too, except that the track is quantized space and the gear engaging on it is another basic physics effect chosen to give a minimum energy state when aligned with the appropriate quantum states on the track. It doesn’t really matter what kind of interaction is used as long as it is quantized, and most physics fields and forces are.

Fortunately, since most future physics will be discovered and consequential engineering implemented by AI, and even worse, much will only be understood by AI, AI will do most of the design here and I as a futurist can duck most of the big questions like “how will you actually do it then?” and just let the future computers sort it out. We have plenty of time, we’re not going anywhere far away any time soon.

An electric motor in your washing machine typically has a lot of copper coils that produce a strong magnetic field when electricity is fed through them, and those fields try to force the rotor into a position that is closest to another adjacent set of magnets in the casing. This is a minimum energy state, kind of like a ball rolling into the bottom of a valley. Before it gets a chance to settle there, the electric current is fed  into the next section of coil so the magnetic field changes and the rotor is no longer comfy and instead wants to move to the next orientation. It never gets a chance to settle since the magnet it wants to cosy up with always changes its mind just in time for the next one to look sexy.

Empty space like you find between stars has very little matter in it, but it will still have waves travelling through it, such as light, radio waves, or x-rays, and it will still be exposed to gravitational and electromagnetic forces from all directions. Some scientists also talk of dark energy, a modern equivalent of magic as far as I can tell, or at best the ether. I don’t think scientists in 2050 will still talk of dark energy except as an historic scientific relic. The many fields at a point of space are quantized, that is, they can only have certain values. They are in one state or the next one but they can’t be in between. All we need for our quantum rack and pinion to work is a means to impose a field onto the nearby space so that our quantum gear can interact with it just like our rotor in its electrical casing.

The most obvious way to do that is to use a strong electromagnetic field. Why? Well, we know how to do that, we use electrics, electronics and radio and lasers and such all the time. The other fields we know of are out of our reach and likely to remain so for decades or centuries, i.e. strong and weak forces and gravity. We know about them, and can make good use of them but we can’t yet engineer  with them. We can’t even do anti-gravity yet. AI might fix that, but not yet.

If we generate a strong oscillating EM field in front of our space ship, it would impose a convenient quantum structure on nearby space. Another EM field slightly out of alignment should create a force pulling them into alignment just like it does for our washing machine motor. That will be harder than it sounds due to EM fields moving at light speed, relativity and all that stuff. It would need the right pulse design and phasing, and accurate synchronization of phase differences too. We have many devices that can generate high frequency EM waves, such as lasers and microwaves, and microwaves particularly interact well with metals, generating eddy currents that produce large magnetic forces. Therefore, clever design should be able to make a motor that generates microwaves as the rack and the metal shell of the microwave containment should then be able to act as the pinion.

Or engineers could do it accidentally (and that happens more often than you’d like to believe). You’ve probably already heard of the EM drive that has NASA all excited.

https://en.wikipedia.org/wiki/RF_resonant_cavity_thruster

It produces microwaves that bounce around in a funnel-shaped cavity and experiments do seem to indicate that it produces measurable thrust. NASA thinks it works by asymmetric forces caused by the shape of their motor. I beg to differ. The explanation is important because you need to know how something works if you want to get the most from it.

I think their EM drive works as a quantum rack and pinion device as I’ve described. I think the microwaves impose the quantum structure and phase differences caused by the shape accidentally interact and create a very inefficient thruster which would be a hell of a lot better if they phase their fields correctly. When NASA realizes that, and starts designing it with that theoretical base then they’ll be able to adjust the beam frequencies and phases and the shape of the cavity to optimize the result, and they’ll get far greater force.

If you don’t like my theory, another one has since come to light that is also along similar lines, Pilot Wave theory:

https://www.sciencealert.com/physicists-have-a-weird-new-idea-about-how-the-impossible-em-drive-could-produce-thrust

It may well all be the same idea, just explained from different angles and experiences. If it works, and if we can make it better, then we may well have a mechanism that can realistically take us to the stars. That is something we should all hope for.

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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 https://timeguide.wordpress.com/2016/07/25/carbethium-a-better-than-scifi-material/. 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.