Gas Tube Number Generator

Randomness isn't a property of anything. It isn't part of nature; it's a made-up human "problem". Any consensus of what constitutes a definition of "random" is local to some particular discipline that needs it. The whole business is a bit disturbing. For a taste of this, check out this Wikipedia entry on random sequence.

(True randomness is a slippery and difficult concept, entirely unnatural. Vast fields of rigorous study require random sequences; while some portions of the concept of random are easy enough to grasp, there are subtleties that make it deeply weird. (And deeply boring, to most people, many of whom might in fact stop buying lottery tickets if they bothered to know anything about statistics and probability. The people who run lotteries certainly do.)

The Gas Tube Number Generator contains a hardware true random number sequence generator, from which it "extracts" (sic) umm, nothingness whatsoever, and upon a hand-wave (literally!), selects a visual graphical symbol from a random sequence of binary digits. It is therefore an oracle of nothing; it rigorously, provably, provides nor contains any information, bias, opinion, or predictability whatsoever. Which, as it turns out, is a lot of work.


Left alone, the Gas Tube Number Generator internally produces random binary digits at a rate of approximately 100,000 to 250,000 per second. The computer samples this stream approximately 10,000 times per second, assembling a 16-digit binary number that in effect ranges from 0 to 65535, decimal. This process remains hidden inside the machine.

Every so often -- randomly! between 20 to 30 seconds -- one of the numbers from this random stream is sampled, and used to create a symbol on the visual character display on the front of the machine. This character persists for a few seconds, and the display reverts to shuffling through randomly lit segments.

There is also a light-sensitive device on the front panel, below the white lamp. When "sufficient" change in lighting occurs (eg. from a rapid hand-wave) the machine produces a randomly selected character. Smaller changes in light, insufficient to produce a character, serve to perturb the noise tube's magnet current. This certainly affects the distribution of chaotic electrons within the tube, which are the source of the noise. If hand-wagging is continuous, the perturbations become larger, hence the magnetic field grows very large or very small, which is clearly audible in the loudspeaker on the front panel of the machine.

(Here is a small movie of a symbol being selected randomly.)

What is the affect of this human (or environmental) perturbation of the magnet have on the random sequence produced? I have no idea.

(Here is a small movie of digit distribution visualized by the Magic Eye tube.)


The fundamentals here speak to many things:

matter and energy are different states of the same thing. under extreme circumstances matter can be converted directly to energy; atom(s) of one element splits into one or more atoms of other elements, and release energy. however, state changes of this kind are rare (eg. "nuclear energy").

far more common are lower-energy state-change within atoms involving mainly electrons. this is called "chemical" or "electrical" energy. these interactions are unthinkably frequent and are the basis for overwhelmingly-most change in matter, living or otherwise.

information is a state (a property) of matter; information is pattern observed or imposed upon matter. there is no information without matter, and all information transfer involves energy transfer.

patterns "emerge" -- are observed (or created) by us, beings composed of matter -- defined as information, against a background of non-information -- chaos, or noise.

"randomness" is defined by states of matter in which humans or their agents cannot detect patterns. non-patterned states of matter humans declare to be informationless.

there is no ground state, the earth beneath our feet is in motion, everything is literally, measurably, relative to everything else. there are no absolutes, anywhere, and all patterns are temporary, even yours and mine.

these things we know.


At the very dawn of automatic electronic computing machinery, 1948, the Rand Corporation built an electronic machine with which to generate the contents of a book titled "One Million Random Digits and 100,000 Normal Deviates". The book is a large mathematical table, rigorously proven, perversely or hilariously, to contain absolutely no information -- it is an anti-table. Instructions for its use read like a card trick. It contains a random sequence of decimal digits from an anti-oracle; the heart of it an electronic component that reliably produced noise when operated outside of it's original design parameters. Rand's machine was a difficult challenge for the time, but the "high quality" sequence of random numbers so produced, at great expense, was sorely needed for theoretical work on nuclear bombs, amongst other things.

The Rand machine's internal generator of randomness was a noise source, a type 6D4 gas-filled thyratron electron tube, in a crossed magnetic field. The 6D4 was designed during World War Two to be a simple electronic relay, but it was found to have a second career as an excellent source of electronic noise. As far as I can tell, the underlying phenomenon, the chaotic motion of electrons within the tube, was first exploited by Cobine and Curry, 1946, with practical ramifications of electrons in a magnetic field documented back to the beginning of the 20th century. How or why Cobine and Curry came upon this phenomenon and applied it to noise generation remains unknown to me after months of research. I am fairly certain that the above paper is the first publication of this as a usable source of noise, as nearly all applications of the 6D4 as noise source date after it's publication.

The Gas Tube Number Generator uses the same component as its source of randonmess. Like Cobine and Curry, I have placed the 6D4 thyratron in a cross magnetic field of approximately 375 gauss, oriented exactly as described in the article. I obtained exactly the same results, as seen on my late-20th-century oscilloscope (such gear unavailable to the authors), photo below. My machinery deviates from theirs in that I made my magnet electrical, the current for which is regulated by a small computer, so that can be influenced by human behavior, as described further on.

In 1948 the electronic state of the art was such that it was a substantial engineering feat to eke reliable non-sense from the thing; RAND's George W. Brown jests in a 1949 RAND history (document P113):

My own personal hope for the future is that we won't have to buld any more random digit generators.�h

Things have changed such that it is now feasible in a (demented) artist's workshop.


Where my Atomic Number Generator used the natural decay of uranium ore from Grants, New Mexico for it's own particular story, the Gas Tube Number Generator explores messier human ends.

Clearly, if a sequence of numbers is truly random, it does not follow any pattern. But what is "pattern"? There are patterns that humans perceive innately, and many more patterns discernable only through aids such as mathematics or machinery. There are other criteria for determining randomness, but that's a central one for human purposes. It is certain that a truly random number sequence, that meets whatever rigorous standards you'd like to apply, shall contain no pattern.

Hold that thought for a minute.

Now the pursuit of science has been for some time moving away from external absolutes ("the sun is the center of the universe") in both practical and theoretical ways. Even matter hardly stands still; it turns out that there is no "ground" from which to measure anything, quite literally everything is measured against some (often arbitrary) standard.

That said, many "absolutes" remain, but they are all essentially relationships (ratios), not concrete "things": the ratio of circumference to radius, speed of light (though that is being assailed, it hasn't budged yet), quanta, etc. Many things that seem like "things" are made up, like an ampere of electrons, or side-effects of biology, like "red".

Back to randomness: random sequences are one of the few remaining external absolute standards. There exists the concept of "absolute zero" temperature, the utter lack of thermal energy, but I do not think anyone has any illusion that it "exists" in any concrete way. But the complete lack of information -- true randomness -- while as abstract as absolute zero temperature, still requires a physical, existent, machine to produce it, though even that isn't that simple -- for a hardware random number sequence generator used as a source for mathematical ends can't really be trusted, as is, it must be constantly tested -- "yup, still can't find any pattern in there".

So what the hell is really going on here? We (humans) make a black box to exacting standards, a thing that dynamically gets rid of any pattern, information, whatever. But this can never truly be proven, the best that can be said is "none of the patterns has been found". I'm not implying that the machine will produce an arbitrarily long un-discerned "pattern" (like the pattern of digits of pi, that visually formed a circle, in the movie CONTACT) or other quasi-religious paraphenomena.

I consider a true random number sequence generator -- such as mine, though I will likely never bother to rigorously test it -- to be different from pre-quantum "standards" apparatus (standard cells, platinum meter bars, etc), and more analogous to modern "relative standards" -- time and length measurement based upon the resonance of a particular molecule, where the accuracy is determined by our ability to measure it. But even here randomness is an inverse of measurement -- it requires believing that we can't measure anything.

I just think this is a little bit weird. Not doubting it's usefulness or correctness, just saying it's a little bit weird. So I made a weird machine.


I was recently asked, 'why do all this?', the implication being that i could have simply faked it. To me, this question drags in a complex of assumptions about what art is; and questions like this are why, when asked 'what i do', i say 'i make things'. i don't generally offer to call myself an artist. i am an artist; i make art; i'm not ashamed of it, or confused, or being arch or contrary. but so many people drag in unquestioned baggage with label-words like 'artist' that i try to describe myself with verbs, instead.

Why do this? (Meaning, why make an arguably real, rigorous hardware random number generator when simulation would seem to suffice; no one would notice.) Because i wanted to know. I think to many, maybe most, people art means 'artifice', illusion, or fake. Often it is, and that's great. But there's a lack of dialog in assumptions that belies indifference or ignorance.

I make things to ask questions, not answer them, to interrogate the world. Physics and science and the philosophy thereof is what's interesting to me.

Construction details

Details of the electromagnet wiring procedure. Not shown (sic) is the spreadsheet used to design the things. 600-something turns of #30 magnet wire. Started out solenoid wound, by halfway it turned jumble-wound. No matter, shellacked paper hides the ugliness. And electrically it doesn't matter, as they're operated at basically DC anyway.

I made a jig to feed wire from the spool, directly onto the solid-iron core (DC, no eddy currents).The cores were simply chucked into a Ryobi hand drill, run at very low speed. The core was insulated with a layer of paper and shellac. Teflon blocks corralled the wire into shape, and shellac doesn't adhere to the teflon. Shellac was painted on after each winding layer. The shellac was allowed to dry, mounted in a vise, with the flying leads restrained. The somewhat delicate coil was then paper wrapped and dipped in shellac once a day for half a week. It took about a week to make the two coils (with little effort other than the winding).

This is the second test jig for the 6D4 and newly-wound magnets. (The first one was just a crap kludge where I waved magnets around by hand for proof of concept, before I began any construction.) The 'scope display shows the noise voltage on the tube (eg. chaotic noisy electron current between cathode and plate), textbook grass noise.

Box construction and layout. I couldn't find a ready-made box so I constructed one from 3/8" thick Micarta with a welded steel frame. Rather overkill and a pain to assemble. Exposed metal is aluminum, with brass hardware. The Micarta is shellacked, sanded, then waxed.

Chassis layout, of even the most mundane technical gear, is an art. Especially with human-interface components, proper placement is more a matter of avoiding bad layout than worrying about corrent layout. Good design is invisible; more accurately, good layout lets the functional components speak without confusion; emphasizes what is important and leaves lesser details to be found as necessary or not at all.

The phosphor screen for the electromechanical/laser oscillograph (sic) was developed tediously, try after try. The reticle is #32 litzendraht wire (aka litz wire) stretched over glass, affixed with urethane, then coated with strontium aluminate powder. The devil is in the details. Took four attempts to get one to work; the first one took a week, the last one about four hours. There's a photograph taken at 4X magnification showing how crossed wires are treated; before the urethane has fully cured, each wire-cross is pressed down with the tip of an exacto blade. When this was not done, phosphor powder got under the crossings and made the reticle blurry.

The magic eye tube, super high tech in 1938 (still pretty today) is an awkward thing, but not hard to work with. It does get hot though. The photo here shows one "eye" open, there's actually two.

The 13-segment DIPlite display uses incandescent wire filaments. A very nice display, about twice as power-hungry as an LED display, but the physicality of the light is nicely visceral. These are not "obsolete" displays; they are still used in avionics. They are rugged, variable brightness, and readble in full daylight.

The sole input device is this simple cadmium sulphide cell. However, fancy-pants differentiation/integration (actually, a PID algorithm (proportional integral derivative)) extracts changes in light. In fact, all of the devices in this box are analog and all are driven with integral or differentiation functions, or both. This is the most math-heavy box I've made to date.

The most obvious idiosyncracy in this box is the longwave UV laser. (Most of my boxen have some bizarre anachronism). $12, post-paid, from China! Came in a lovely fake-velvet-lined black box. The case is electrically hot so it needed this plastic mount.

The most visible output device is the electromechanical oscillograph. Making optical devices is a pain in the ass; so fussy! The laser shoots up from inside the box, hits the tiny front-surfaced mirror affixed to the pretty brass thing between the legs of the horsehoe magnet of the mirror galvonometer.The fixed mirror mount is adjustable.

The mirror galvonometer -- this example probably made around 1940 but they date back to the 19th century, pretty much as it appears here -- is an extremely sensitive (nanoampere) device, a tiny coil of wire suspended on a taut wire, in a magnetic field. They're simply beautiful, working or not.

This assortment of technologies from three major eras requires a lot of interface, a lot of wiring, and lots of different voltages. 5V, 6V (mainly tube filaments), 12V (mainly analog signal processing, and fans), and 250V (tube plates aka anodes). All that power required careful airflow design, not particularly obvious here, but the plexiglas top cover will trap the heat of the two tubes as well as act as a dust collector. Air filtration was required.

The final wiring was not as messy as it appears here, in-progress. The excess length is required though, so that the top can be removed and set on it's side and not damage anything. The last picture in this table is what it looks like, "ready to go".

The trickiest part of assembling this box was the 3D puzzle made by objects attached to the top plate, rear panel and front panel, and the base of the box having to fit together when assembled. There's not a lot of extra room in there, and the tube turret sockets have high voltage on them, nesting down between 5V Arduino logic so mistakes would be costly.

The machine is starting to take it's final shape, though the airflow design isn't finalized here; I ditched the neon high-voltage lamp in the top back left corner and installed the plexiglas cover's positive ventilation/filtration system there.

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