Scintillocartography
(This text is the results of my participation within the “Nuclear Sessions” workshop hosted by Madrid’s Medialab. It’s explicitly revealed beneath a CC-by-sa 4.0 license.)
The difficult factor about ionizing radiation is that it can’t be seen by the bare eye; it can’t be heard, or felt by human senses. We will solely sense it via indirect means.
The tactic that arguably has permeated essentially the most into standard tradition is the Geiger counter. Its most important element, the Geiger-Müller tube is crammed with an ionized noble gasoline; each time radiation within the type of a gamma particle hits the gasoline, it produces a phenomenon often known as an electron avalanche that produces a powerful electrical pulse. If {that electrical} pulse is fed to an audio loudspeaker, it would produce a attribute crackling sound.
Thus, the sound of a Geiger counter will not be the sound of radiation, however of an oblique strategy of interactions between purposefully-made parts: it’s the sound of a loudspeaker being fed an electrical pulse produced by an electron avalanche born in an encapsulated and ionized gasoline.
Our human brains are often not within the interior workings of such a bit of equipment; as a substitute we wish a dependable software with a transparent cause-effect correlation: when gamma radiation is available in, a noise comes out. We ignore the interior workings as a result of the work of engineers has been exactly to summary and obscure the (often uninteresting) interior workings.
Most strategies of detecting and measuring ionizing radiation are likewise oblique: radiation hits A, which impacts B, which in flip impacts C, which impacts D, which impacts one thing that may be lastly perceived by human senses.
The inventive strategy of deconstruction, which has been generally used to interpret a topic, or to research the place a that means comes from and the way it behaves, can’t be utilized to nuclear radioactivity. It both requires complicated instruments, which defy the deconstruction itself, or lethal quantities of radioactive materials, which might clearly be extremely harmful. No scientist of their sane thoughts would expose themselves to the quantities of radioactive materials because the pioneers of the early 20th century did to themselves; even among the many flat-earthers and the vaccine deniers one can’t discover a single one that thinks that licking enriched uranium is protected, or that there’s a world conspiracy simply to forestall the usage of thorium to remedy complications. The written reviews of sickness and dying from the primary many years of the 20th century have ensured so.
Observing the direct results of radiation, though potential, requires extraordinary circumstances.
A kind of circumstances is being near a nuclear reactor submerged in water, which permits Cherenkov radiation to be noticed. In layman’s phrases: gamma radiation exits the reactor on the pace of sunshine in a vaccuum, however the pace of sunshine in water is decrease, and photons need to decelerate someway. The direct, observable impact is that water glows blue.
This blue glow has barely entered standard tradition. The one two examples I’m conscious of are the cinematographic depictions of the Chernobyl catastrophe, and the ficticious Nuka-Cola Quantum non-alcoholic beverage within the Fallout videogame collection.
Amazingly sufficient, most different depictions of radioactive glow are both inexperienced (within the supplies, to indicate toxicity) or orange (within the reactors, to indicate heat). Nuclear energy is so alien that it even defies the semantics of colors.
The opposite extraordinary circumstance that enables observing radiation in a direct manner is being exterior of the earth’s magnetosphere. Astronauts travelling to (and from) the moon have reported a phenomenon known as both Astronaut’s eye, light flashes or cosmic ray visual phenomena.
This phenomenon will not be absolutely understood because of the very restricted quantity of occurences, however the scientific consensus is that cosmic radiation hits the astronaut’s eyes (both the vitreous humour, the retina, or the optic nerve), which interprets within the particular person “seeing” (principally) white dots, (typically) white strains, and (hardly ever) clouds or blobs.
I’m most on this phenomenon, because it is among the few observations of radiation that people can expertise instantly, and likewise has parallels to some oblique technique of remark used. This sudden look and dissipation of white dots is known as scintillation (from the latin scintillāre that means “to glitter, glitter, gleam, flash”); and there even exists a whole department of nuclear physics named scintillography, which research learn how to file radiation via observing the sparkles that it leaves behind.
This notion of radiation as its sparkly file, I argue, may be generally understood by the scientifically inclined. In any case, the form of atoms – specifically, the Rutherford model – is taught as a part of high-school physics, as is Rutherford’s gold-foil experiment. We all know {that a} managed radioactive supply will imprint white dots on a photographic plate, or on a phosphorescent materials. If now we have ever listened to a Geiger counter, we are able to additionally think about the random cadence at which these dots are imprinted.
Maybe this analogy will probably be misplaced sooner or later. We stay in an period the place cathode-ray tubes (these in televisions or scientific tools akin to oscilloscopes) are however a museum piece, and the technology of people that operated computer systems by watching inexperienced phosphor screens is rising previous. Again within the Eighties, everyone knew that shutting down a tv would depart a lingering white line, then a lingering white dot at its middle, a logo of what occurs when the human mechanisms of controlling rays of power fail expectedly.
Analogies to the behaviour of human-made contraptions have failed prior to now. Reminisce, if you’ll, about «the colour of a tv turned to a lifeless channel» in William Gibson’s “Neuromancer” novel, or «the sounds of large plane warming up on the ends of their runways» in J. G. Ballard’s post-nuclear wasteland. Televisions have gone from silvery noise to blue to black to psychedelic swirls, and planes have gone from propeller blades to turboprops to ramjets to turbojets to turbofans to scramjets. How many individuals keep in mind the sound of the Concorde’s hypersonic afterburners revving up? How many individuals keep in mind how connecting to the web gave the impression of within the Nineties?
It may be argued that now we have already handed the height level of historical past when the social imaginary most correlated scintillation with radiation. I’ll say that the height was somewhen between the nuclear utopianism years of 1950 and 1951, when the Gilbert U-237 Atomic Energy Laboratory, a youngsters’s instructional toy, was within the cabinets of toy shops. It notably included a cloud chamber: an equipment the place alcohol vapour momentarily condenses, forming little cloud trails that sparkle into existence.
Cloud chambers appear to be a factor of the previous. One can ask to see the array of gamma detectors at a civil radiology laboratory, however there are not any cloud chambers to be seen. And, alas, I found a bit too late that the CERN (Conseil Européen pour la Recherche Nucléaire) provides instructions on how to build your own, with pharmacy-grade isopropyl alcohol and frozen carbon dioxide (AKA “dry ice”):
(Nonetheless picture crom CERN’s video: LHC communicator Sarah Charley explains learn how to make a cloud chamber)
A cloud chamber, although it’s nonetheless an oblique methodology of remark, replaces the synthetic shell of a Geiger counter’s plastic casing, and the thick lead partitions of a gamma counter, with a pane of glass. Whereas nonetheless a human-made assemble, it’s a rawer remark, unencumbered by inscrutable digital parts.
(Nonetheless picture crom CERN’s video: Cloud chamber exhibiting vapour trails of radiation)
I consider that graphical scintillation is an acceptable manner of conveying radioactivity. I is likely to be mistaken, and it would develop into out of date, however that gained’t forestall me from, not less than, making an attempt.
The core of my skilled expertise lies on the conjuction of cartography, web site growth, and laptop graphics. I inform computer systems how to attract maps, throughout the handicap of an internet browser, whereas making an attempt to squeeze essentially the most out of a graphics card. For the last few years I’ve been working on a software library called Gleo; certainly one of its targets, maybe one too pretentious, is to replace the variables obtainable to graphic semiology.
Graphic semiology in maps has remained principally unchanged since French cartographer Jacques Bertin revealed Sémiologie Graphique in 1967. Cartography works with six variables: measurement, worth, texture, color, orientation and form. However a map on a pc display differs from a map on paper (amongst different issues) in that it will possibly change with time, i.e. it will possibly embody an animation; DiBiase et al revealed Animation and the Role of Map Design in Scientific Visualization in 1992 arguing that laptop graphics enable for extra variables: length, price of change, order; and after MacEarchen’s work we think about show date, frequency, and synchronization.
With these animated semiological variables we are able to attempt to convey radioactive scintillation via a map. It’s potential to twinkle cartographic simbols into and out of existence, in a way that can’t be performed in a static graphic. I intend to use scintillation to cartography, therefore the time period scintillocartography.
The realm of scintillocartography began, maybe, in 2010, as an post-conference alcohol-induced dare, the place just a few fellow cartographers had been discussing if it will be potential to use the expertise of glittery-looking animated GIFs of the Nineties to map photos. And certainly it was: an image animation process to mimick glitter was utilized to a restricted variety of map tiles (sq. photos that make up internet maps), and so TEH GLITTERMAP!!!1! was born, a comedy-by-excess approach to reminisce the meme of 90s glittery webpages.
The second iteration of TEH GLITTERMAP!!!1! swapped the offline picture processing for WebGL shaders. As an alternative of getting to precalculate the glitter animation beforehand, it’s potential to inform an internet browser to use the scintillation to the map picture in actual time. The WebGL shader runs an edge detection algorithm (in order that solely pixels in areas of fixing color are affected), a color area transformation (from red-green-blue to hue-saturation-value), and applies a pseudorandom variance to the brightness (worth) of pixels.
It’s price noting that The Book Of Shaders by Patricio González Vivo has been instrumental in enabling the understanding and creation of WebGL shaders. It is usually price noting that whereas radioactive decay shows true randomness, it isn’t potential to realize true randomness in computer systems with out important work. Computer systems can generate pseudorandom numbers simply – although they’re not match for purposes the place true randomness is required (akin to cryptography), these look random sufficient to the human senses, specifically when paired with numerical strategies to cover their patterns.
For the work in Nuclear Sessions I’ve used a 2017 dataset of radon potential, published by the Spanish Nuclear Safety Council. This highlights the geological potential of the terrain to construct up radon gasoline, significantly in built-up basements with dangerous air flow, and when sure varieties of stone are mined from quarries. The default visualization is a plain map with a 5-colour categorical scale:
(Map of Radon Potential in Spain, CSN, 2017)
This dataset was chosen purely on the premise of availability: it was the best (and first) geographic dataset concerning radiation to be discovered. The collection of dataset (and the dialogue of which radiation-related datasets can or needs to be displayed) is out of the scope of this text. The intent is to present an outline of the approach, and to verify (or deny) the hypotheses that scintillation in a map can convey radioactivity.
The prototype implementation depends on easy concepts: as a substitute of drawing the polygons of the radon dataset as colors, they’re drawn as a scalar area – that means one invisible quantity per pixel. At a second go, every pixel is turned white if the worth of the sphere in that pixel is larger than a (pseudo)random quantity. If the (pseudo)random quantity is larger, then the pixel is discarded, which interprets as being clear and letting the background darkish basemap to be seen.
In additional technical OpenGL/WebGL phrases: the primary rendering go renders the polygons right into a framebuffer with a R32F
texture as its color attachment, and shops the numerical worth related to the radon danger. The second rendering go makes use of that texture, in addition to one other R32F
texture containing pregenerated (pseudo)random noise. For efficiency causes, the (pseudo)random noise texture is reused, however a (pseudo)random offset is utilized to its texel coordinates, on a per-frame foundation.
The GLSL program used within the WebGL fragment shader is as follows:
void most important() {
// Fetch the worth of the scalar area for this pixel
float worth = texture2D(uField, vUV).x;
// Fetch the worth of the pseudo-random quantity for this pixel
// Word that uRNGOffset is about to a pseudorandom worth at every rendering body.
float prob = texture2D(uTwinkleRNG, (vUV + uRNGoffset) / uRNGsize ).x;
// If the worth of the sphere is larger than the pseudo-random quantity...
if (worth / uMaxIntensity > prob) {
// ...then give the pixel the specified color (in our case, white)...
gl_FragColor = uColour;
} else {
// ...and if not, discard the pixel, leaving it clear.
discard;
}
}
For the reason that result’s animated, it can’t be correctly conveyed in written type. Its look does resemble a dot density map, with larger values of the dataset variable (radon potential) displaying as larger density:
(Scintillating map, utilizing knowledge of CSN’s 2017 Map of Radon Potential in Spain)
The animated nature of the scintillating map can’t be proven in written type; and since I’m assuming the worst case that you simply’re studying this text printed on a lifeless tree (i.e. paper), these 5 nonetheless frames from a bit of the map ought to illustrate that the scintillating pixels change each body (i.e. 30 instances per second):
(Frames of scintillating map, utilizing knowledge of CSN’s 2017 Map of Radon Potential in Spain)
There’s additionally a webpage with the scintillating map prototype, however beware that it will possibly take a few minutes to load (resulting from an unbeknownst problem within the strategy of triangulating the dataset polygons).
Does this prototype of a scintillating map convey radioactivity? I feel the reply is “sure, however not adequate”.
The (pseudo)random scintillation of the white dots feels adequate at conveying chaos and randomness, and likewise at conveying exercise (as in radioexercise) and a little bit of aggression: the info will not be a transparent particular graphic however an alive-looking amorphous factor; a noise that damages the picture and prevents us from seeing (what we consider to be) the territory.
The various likelihood of a pixel scintillating does work at conveying the relative values of the dataset. Nevertheless, a linear enhance in likelihood (which instantly interprets to density) doesn’t really feel like a linear enhance within the perceived worth. The numerical values of the chosen dataset (which differ from 1 to five) are cubed (making them differ from 1 to 125).
The most important shortcoming of this prototype is the absence of persistence. Ideally, the scintillation would persist in time for an length just like that of a cloud chamber path (between half a second and two seconds), and never disappear on the subsequent rendering body. A graphical scintillation ought to, as properly, come into existence abruptly however fade out easily.
These modifications ought to, hopefully enhance the conveyance results higher. Sadly they don’t seem to be trivial to realize on the technical facet: they might require both a 3rd rendering go (and one other framebuffer to retailer the pixels presently scintillating and their remaining time), or the appliance of a Montecarlo algorithm out of the GPU earlier than the primary and second go (to spawn the scintillations) plus an overhaul of the second rendering go (which might simply draw the scintillations as a substitute of performing calculations on full-screen textures).