Browsing the Internet, I had an idea.

There are currently prototypes of “3D printers for printing houses“. As an extension to this, and especially interesting for the developing world: how about a robot that can autonomously dig a house underground, consuming just water and electricity and needing nothing in addition to build the full house? It would be able to create no-cost housing anywhere.

Here is how:

The digbot / underground 3D mill will use a water jet cutter for cutting the soil, maybe photovoltaics for electric energy, and be totally autonomous, controlled by a CAD drawing. It will harvest stones from the cutting area, cut them with the water jet also, and use them to build the walls and ceiling (employing a vault for stability). It should be a self-moving tracked vehicle. It should also be able to carry the cut-off material to the outside itself, or this should be delegated to another self-moving tracked robot.

The underground facilities produced that way can be living space in developmnet countries; in many parts of Africa, no inner anti-groundwater equipment is necessary, as the groundwater level is below 30m; else, a waterproof full inner plastic sealing, insulation and pump is the simplest form. The bot also should be able to create its own abrasive for water jet cutting from hard stones it finds, and to create sand etc. from the stones for mixing concrete, and to apply the concrete for connecting stones (only if necessary) and for creating some. It is no problem if the bots operate quite slow, as it is an unattended, unmanned build process.

The first step to realize this invention would be a tunnel-cutting robot, which can be a shield-shaped one using sprayed concrete and transporting the cut-off stuff on a band conveyor, and receiving concrete, abrasive, electricity etc. likewise in tubes.

Oh, by the way: here are some prices for used water jet cutters.

The Internet contains a subculture for everything imaginable. Here is the Fabber subculture. This is especially cool that such a thing exists, as I envisioned something in that direction, esp. also for EarthOS. Here it is: the culture of creating your products yourself.

They have, so far:

  • the public inventory list for the “official” MIT fab lab specification
  • the FabCentral tools list for fab labs
  • the Makerbot, a fully open source plastic 3D printer to build yourself, backed by a company
  • the Bits from Bytes RepMan V3.1, an affordable, high-quality 3D printer for building yourself (based on RepRap Darwin principles)
  • the Bits from Bytes BFB 3000, the first fully assembled 3D printer for under  GBP 2000 (based on RepRap Darwin principles, but improved, and seemingly not that “open” as Makerbot / RepRap Mendel etc.)
  • the RepRap project, aiming at creating a self-replicating 3D printer machine, can also be built at home
  • the Fab@Home project, also an open source 3D printing (and also robocasting) project; currently, mainly printing with silicone, either direct objects from that or molds for filling in Epoxy
  • the Machines that Make project from the MIT Center for Bits and Atoms; I especially like the “fab in a box” project, which is close to the fab lab concept I have in mind
  • upcoming lower-cost commerical 3D printers, like the HP Designjet 3D printer for 13,000 EUR
  • the Thingiverse, which is like the Fabber’s SourceForge, containing downloadable data for products to mill, lathe or 3D print, tool descriptions, supplier registration for products etc.; one can already find hundreds of geometry files to download to make ones own products. Nice examples:
  • open source 3D modeling software like Art of Illusion
  • the Mobile fab lab, kind of what I want for my A-2 equipment
  • a first fab lab in Germany, open to everybody
  • FabAcademy, something like the online university for digital fabrication (as of 2010-04, they offer self-accredited certificates and diplomas, but no officially accredited Bachelor or Master yet)
  • YouTube videos on the fab lab
  • MIT index of more material on the fab lab

Some background knowledge from Wikipedia:

Ok, and what do I want to do with this stuff when I have my own fab lab? Research, how to use it. What to do with it. Make my own things. Design my Equipment System so that many things of it can be made in the fab lab. And: check if development countries can profit from fab labs. There, transportation and logistics is a big problem, so making all the parts instantly in place when demanded would be a solution. I imagine a hackerspace in Africa where people help themselves to build everything up. Inspirations:

The printed plastic parts can even be re-used to make new ones. This would be about adding the intelligence of a fab lab to local materials, to create wealth out of nothing, in an autarchic community. It would include working with stone in a 3 axis CNC mill, or even on a CNC angle grinder for cutting stone. I currently have a draft for such a machine in my TEQ4 Equipment System notes, which can create CNC-cut, LEGO brick style stones to build houses and many other structures from. Very durable stuff, made from cost-free material that just lies around!

Something happened today that has not happened for a long, long time since I know the Internet. I was seriously bedazzled. Totally speechless. I read through complex scientific texts for hours, understanding less than half, and still wondered if all this is just a big fat joke.

Fact is, I found a blog of a guy who claims to have done nuclear fusion at his home … a star in a jar, including a 200 million degree plasma. And now he attempts to build a fusion reactor, at home. And there are several other hobbyists, approx. 24 worlwide [source], who also achieved nuclear fusion at home. I have read about home-made electron microscopes etc., and that would not be stunning to me any more … but nuclear fusion? This is so awfully crazy … hope he succeeds with the reactor 🙂

See for yourself:

I spent the day tracing some really bad bugs. Here are some good 1972 quotes from Dijkstra, who recognized the danger of unmanaged software complexity that early.

“Finally, although the subject is not a pleasant one, I must mention PL/1, a programming language for which the defining documentation is of a frightening size and complexity. Using PL/1 must be like flying a plane with 7000 buttons, switches and handles to manipulate in the cockpit. I absolutely fail to see how we can keep our growing programs firmly within our intellectual grip when by its sheer baroqueness the programming language —our basic tool, mind you!— already escapes our intellectual control. And if I have to describe the influence PL/1 can have on its users, the closest metaphor that comes to my mind is that of a drug. I remember from a symposium on higher level programming language a lecture given in defense of PL/1 by a man who described himself as one of its devoted users. But within a one-hour lecture in praise of PL/1. he managed to ask for the addition of about fifty new “features”, little supposing that the main source of his problems could very well be that it contained already far too many “features”. The speaker displayed all the depressing symptoms of addiction, reduced as he was to the state of mental stagnation in which he could only ask for more, more, more… When FORTRAN has been called an infantile disorder, full PL/1, with its growth characteristics of a dangerous tumor, could turn out to be a fatal disease.”


I now suggest that we confine ourselves to the design and implementation of intellectually manageable programs.

[…] Argument one is that, as the programmer only needs to consider intellectually manageable programs, the alternatives he is choosing between are much, much easier to cope with.

Argument two is that, as soon as we have decided to restrict ourselves to the subset of the intellectually manageable programs, we have achieved, once and for all, a drastic reduction of the solution space to be considered.

[…] We all know that the only mental tool by means of which a very finite piece of reasoning can cover a myriad cases is called “abstraction”; as a result the effective exploitation of his powers of abstraction must be regarded as one of the most vital activities of a competent programmer. […] Of course I have tried to find a fundamental cause that would prevent our abstraction mechanisms from being sufficiently effective. But no matter how hard I tried, I did not find such a cause. As a result I tend to the assumption —up till now not disproved by experience— that by suitable application of our powers of abstraction, the intellectual effort needed to conceive or to understand a program need not grow more than proportional to program length.

[…] Up till now I have not mentioned the word “hierarchy”, but I think that it is fair to say that this is a key concept for all systems embodying a nicely factored solution. I could even go one step further and make an article of faith out of it, viz. that the only problems we can really solve in a satisfactory manner are those that finally admit a nicely factored solution. At first sight this view of human limitations may strike you as a rather depressing view of our predicament, but I don’t feel it that way, on the contrary! The best way to learn to live with our limitations is to know them. By the time that we are sufficiently modest to try factored solutions only, because the other efforts escape our intellectual grip, we shall do our utmost best to avoid all those interfaces impairing our ability to factor the system in a helpful way.

[…] Hierarchical systems seem to have the property that something considered as an undivided entity on one level, is considered as a composite object on the next lower level of greater detail; as a result the natural grain of space or time that is applicable at each level decreases by an order of magnitude when we shift our attention from one level to the next lower one. We understand walls in terms of bricks, bricks in terms of crystals, crystals in terms of molecules etc. As a result the number of levels that can be distinguished meaningfully in a hierarchical system is kind of proportional to the logarithm of the ratio between the largest and the smallest grain, and therefore, unless this ratio is very large, we cannot expect many levels. In computer programming our basic building block has an associated time grain of less than a microsecond, but our program may take hours of computation time. I do not know of any other technology covering a ratio of 1010 or more: the computer, by virtue of its fantastic speed, seems to be the first to provide us with an environment where highly hierarchical artefacts are both possible and necessary.

This quote was originally published in the journal “Commununications of the ACM”, 15 (1972), 10th edition, on pp. 859–866. Sources:

I’m jus’ sitting here, listening to some Reggae on Radio Paradise and having dinner. Doing so, I solved the squaring of the circle problem.

This happened when I was slicing a cylindric piece of sausage. Tired of round slices, I put the piece upright and noticed that the slices are now rectangles of different sizes. Then, I transfered this to the circle as something like an “infinitely thin piece of sausage”. Cutting it in “upright position” (sounds strange with height=0, though) and cutting inifinitely thin slices gives rectangles of height zero, that is, lines. Now, you can connect the lines piece by piece to one infinitely long line, and cut that into an infinite number of other lines, each the lenght of one edge of the desired square. Now put the lines next to each other like matches in a box (but only one layer) and you have the square.

I looked the problem up in Wikipedia afterwards, and solutions like this one are probably meant where they state: “Bending the rules by allowing an infinite number of compass-and-straightedge operations […] also makes squaring the circle possible.” (English Wikipedia, on the impossibility of squaring the circle).

The static reach of the world’s exploitable Uranium is 70 years. Which means it’s fairly easy to solve the problem of nuclear weapons once and for all.

A state would have to devote itself to consume as much nuclear material in reactors as possible. They’d build new reactors and buy nuclear material worldwide. That way we’d get rid of all consumable Uranium worldwide within 15-30 years. Nobody could build a nuclear weapon again. Forever.

Start date: 2009-01-19
Post date: 2009-01-19
Version date: 2009-01-19 (for last meaningful change)