6-bit Rays & Dimensions
(1) 6-Bit Rays : A device generates sound and light pattern from subatomic particles and radiations. (2) Dimensions : Shapes and sound from sampled 2-Dimensions from actual 3-D radiation field.
produced by: Philip Liu
(1) 6-Bit Rays
There are so many things in the world, we cannot see or hear, than we can. Range or human hearing is just a fraction of entire vibrations exists in the earth, also visible spectrum of human eye is extremely limited. As technology develops, human are gradually being able to hear and/or see more things, and it is one of the desire that modern human has. ‘I want to figure out all of the abstract things in the universe by my ears, eyes and hands’. And interestingly, visualizing/sonifying invisible/inaudible things often yields interesting patterns, images and sound which are highly likely not be able to be reproduced by human.
This work, 6-Bit Rays is about sonifying and visualizing one of those things, subatomic particles and radiations.
Stochastic process is also an important element of this work. The word stochastic means ‘having a random probability distribution or pattern that may be analysed statistically but may not be predicted precisely’. In other words, stochastic process can be reproduced similarly if we have all of the mathematic equations and values, but it can’t be exactly same as before.
This idea of stochastic process is very closely related to many things in art or music (even though it is not actually defined as a stochastic process). For example, can a violin player make exactly sound twice? the answer is no. It can never be the exactly same in terms of pitch, amplitude and timbre. Can a painter draw exactly same paint twice? no.
Subatomic particles used in this work, such as Muon, is an obvious example of a stochastic process. It is almost completely a random information, and it’s real, compared to pseudorandomness in computer. Muon is generated from cosmic rays from the sky, and it exists everywhere on the earth. Approximately 10,000 muons per minute strike each square meter of the earth's surface .
-The device : The device is a stand-alone light and sound object. It just needs electricity input and signal output to two speakers. No laptop computer is needed. This device is powered by microcomputer Bela, an embedded device for sound and signals.
-Detecting subatomic particles and 6-Bit to integer conversion : How can the device detects subatomic particles? with Hodoscope. Hodoscope means 3-D array of geiger tubes, and geiger tube detects subatomic particles and radiations. Each geiger counter detects all kind of radiation particles individually and it makes the corresponding bit of the 6-Bit system 1, otherwise it is 0. Each bits are used to turn on and off corresponding bulbs, and also defines a sample value of the sound (= the radiation particle information makes the sound).
-Muons and coincide detection : For the cosmic rays such as Muons, they are usually from the sky and the angle of incoming particles should be close to perpendicular to the ground. so if two vertical tubes detects something at the same time, we can say it is highly likely Muon, not other particles around. It is called coincide detection. If coincide detection occurs, the microcomputer makes significant change in sound.
-Enclosure design : Top and bottom of the enclosure is laser cut wood and the pedestals are 3-D printed PVA. All of the processes are done using Rhinoceros and Grasshopper. On the picture below, left side is actual picture, and the right side is Rhinoceros rendering. All pedestals have different shapes and heights. The front side symbolises order, it depicts a typical detecting pattern of geiger tube, and the heights are calculated from geometric series. The back side is chaos, noise is added to the geiger tube pattern and the geometric series.
-Circuit design : A Geiger tube I've used for this project needs 400V, and Bela needs 5V. It means a separate 400V power supply is needed. Schmitt trigger generates a pulse from a geiger counter, then the pulse width needs to be shortened to obtain more precise detection, so one more Schmitt triggering stage has applied. Then the voltage of the pulses are limited to 3.3V by limiters, so that it does not destroy the Bela circuit. Bela digital I/O pins accepts pulse up to 3.3V.
I think there's a natural extension of this project, it is number of tubes and bulbs. On this work I've focused on making a small and well designed object, but bigger scale often gives a stronger impression. For example, Nine 14-Bit system, which needs 126 tubes/bulbs and 18 speakers would be great. Also I can modify the code for sound generation, to obtain more interesting sound.
Second work of visualizing/sonifying invisible/inaudible things series.
Connecting sound and image is always one of the main interests of artists. There are several ideas of sonifying 2-D and 3-D shapes, but none of them can be said as authentic, because in digital or analogue environment sound is just an array of numbers. It means it is 1-dimensional. It is not as simple as sonifying things already 1-dimensional.
Concept of this work is sonifying and visualizing 3-D radiation field. Radiation fields, whether it is electromagnetic or other thing, most of them is invisible and inaudible. But it is everywhere in the world, and is filling the space around us. It is like a completely transparent paint floating around, and what I wanted to do was to see and hear that.
An alpha radiation source, often used in a smoke alarm, emits alpha radiation. It means it forms a radiation field around it, a continuously moving 3-D shape. By a radiation detector called spark detector, It is possible to indirectly see radiations through dots. As a spark detector I made is 2-D plane, I was able to obtain 2-D slices of the radiation field.
-First thing I did for this project was to purchase alpha radiation source, make spark detectors, generate sparks using the radiation souce, take a video and apply chroma key to remove background. As a result, I could obtain 87 videos that only shows sparks (= shape of alpha radiation). The shape, size and number of sparks are changed depends on what kind of resistor I drop on the cathode of generator. I applied 1Mohm, 5Mohm, 8.7Mohm and 10Mohm resistors. The picture below is a collection of screen captures, from selected 16 videos.
-Sound materials were generated via Physical Modelling Synthesis. The 2-D slice is deemed as very thin metal plate that has same volume to that of a shape generated by connecting the brightest incoming sparks. Due to limits of computing power(unless you have a very high-end computer), in this case, Physical Modelling Synthesis needs to done in non-realtime. So I generated 168 sound samples via Physical Modelling Synthesis first, and then synced it with the shapes. If you want details, see 'codes' link.
I think Physical Modelling Synthesis is ideal method of sonifying 2-D and 3-D shapes, because it actually represents the shape, and through that, a clear mathematical connection between image and sound is established. It is like having a percussion instrument that looks exactly same as an image on the screen. No other image-sound connection is more clear than this. The first picture below represents a procedure of sampled shape to triangles to modes conversion, and the second one shows actual sparks from the spark generator.
-Playback : There are four virtual windows on the screen and each one continuosly selects and plays one of the 87 videos randomly. That is where everything starts. An algorithm recognizes the dots in video, and generates some 2-D shape by connecting the brightest ones. Then it calculates size of triangles, and finds closest sound sample among the 168 samples(generated from physical modelling). As there are four windows, resulting sound output is also four channels. As a result, the video and sound files are pre rendered one, but whole selection and playback process is real-time.
I think this project is going to be more interested if I actually bring spark detector to an exhibition. So that galleries can appreciate actual sparks, video and sound together. But this couldn't be done this time because of two reasons. First, the spark detector operates on very high voltage, so It could be danger. Second, as originally I'm not a hardware type of guy, I have had not enough skill and time to make the spark generator safe, and also not enough to make it stable, so that It can endure 4 days of running time. It only worked for about 3 hours, that was the time I could take the videos. If my skill is improved in the future, I think I'm able to make a 'live' version.
If you want to see even more technical things, such as code, logics and detailed descriptions, check this page : https://www.philipl.net/finalcode
There were some downsides during I'd been preparing this project. First, I couldn't contribute much to the common. I realized that a form 'exhibition' needs much more cooperation from members than a ‘concert’. I came from the (electronic)music composition world, and It is a type of art that barely needs co-work. Also there are relatively less thing that I need to prepare, because some other staffs would organise and prepare things for me. But exhibition is different. I’ve realized this myself and also from the course leader Theo’s advice. I’ve learned that I need to communicate well with other members of an exhibition, and also have to prepare most of things myself. Second, time management. I know that time management is very important if I want to be a professional artist. This time, I finished my work 1 hour and 30 minutes after the exhibition started. This should not happen on the professional exhibition such as Ars Electronica. I need to be more clever, try not to make so many things, and also try to finish work at least 3 days before an exhibition.
There’s not much things changed from the final presentation I've done and the actual exhibition. But as mentioned, I needed to change some things like ‘exhibit actual spark generator VS use pre-recorded video’. Otherwise, most of the things worked as I’d intended.
Thank you so much for the teachers, Theodoros, Atau, Tim, Lior, Mick and Phoenix. And also for the wonderful classmates.
(1) 6-Bit Rays
circuit design referenced from : http://hardhack.org.au/book/export/html/2
'How muons are made' image credit : ASPERA/Novapix/L.Bret
spark detector circuit design referenced from : http://www.imagesco.com/articles/geiger/alpha_particle_spark_detector_p2.html