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Express plants activity (vibrations, electricity...) into sounds/music.
It’s lunchtime, and I’m sitting in front of Cochin hospital, taking a break. A small forlorn weed rising in a corner of the building struggles against the wind. I don’t know why, but I can’t stop looking at it. What if this plant could actually speak ? What kind of sound – or noise – would it emit ? What could we learn from it ? Maybe it’s worth checking out. Something about this gray zone between art and science. So I’ve decided.
« Listening to plants » as a first title.
I don’t really have any clue as to go about it. Maybe it’s really stupid as an idea. But then again, one could imagine that any living object generates some kind of vibration, and this vibration could then be translated into an audible sound. The big idea : When I was doing a BTS Technicien Production Bois, I (we) studied some of the mechanical properties of wood. Although I haven’t retained much of the math, I was always fascinated by the idea that one could use math to explore properties of physical objects. Somewhere further back, art history studies echo also. The concept of« nature » came about only once civilisation had cut itself off from « nature ». Revisiting « nature » through digital tools reformulates this essential question about the distance between our mental constructions – civilisation - and the physical world surrounding us.
As I said, I have no clue as to how to investigate. Nevertheless, I see two paths :
- Create artificial vibrations through external stimuli. This could be, for example, applying an electrical current or inducing a vibration through friction.
- Measuring (and then translating into sound) internal movements, whether they be regular oscillations or non regular jumps.
Option 1 is easy and doesn’t get to the point. Option 2 is much harder but potentially more interesting. If something could actually be measured and made « listenable », the project would ideally find its expression in a public space, a park, that would provoke passers-by. Stop, and listen to what a plant can tell you.
Louis says that he wants to join. Yay !
Found some paths to explore this morning.
On Medium, « Can you hear the stars » https://medium.com/the-white-house/can-you-hear-the-stars-7d05db6a7f4#.21e3uhr84 Astrophysicist Wanda Diaz Merced describes « techniques in sonification, or how we translate data into sound signals. Suddenly, it was possible to detect subtle changes in data patterns, simply by listening to them. »
Joel Chevrier told me that there was a show to check out at the Fondation Cartier, « Le Grand Orchestre des Animaux », inspiré par l’oeuvre de Bernie Krause, musicien et bioacousticien américain.
The dedicated web site http://www.legrandorchestredesanimaux.com is both esthetic and informative. Lots of vocabulary that gives keywords for later research, and ideas to frame out intentions.
To do : See the show, gather keywords and begin research.
Brainstorming :
Louis spoke yesterday about the reactions of plants (induced vibrations) to external sources : wind, cars etc. This is one path for interaction.
Research :
A few people already working on the idea.
https://www.pepiniere-botanique.com/autour-des-plantes/boitier-capteur-musique-des-plantes.html
Alors que certaines cultures très anciennes prêtaient à l’ensemble des êtres vivants et à l’univers même des propriétés de conscience et des facultés de communication, notre civilisation scientifique a longtemps réservé à l’homme la caractéristique de l’intelligence. Nul ne conteste aujourd’hui à la plupart des animaux des propriétés cognitives étendues, de la mémoire longue, une sensibilité et la capacité d’entretenir des relations complexes avec leur environnement, les membres d’une même espèce et ceux d’espèces différentes.
Concernant les plantes, des travaux publiés dans les revues scientifiques s’accumulent et montrent qu’elles sont bien plus actives et réceptives que nous le pensions. Les plantes sont sensibles aux sons et modifient leur croissance lorsqu’elles sont placées dans des environnements sonores différents. Par leur système racinaire, en particulier, elles sont capables de ressentir les variations de l’environnent et de réagir en conséquence. Elles peuvent également transmettre des informations dans tous leur organisme et à destination d’autres organismes.
Bien qu’utilisant des processus très différents de ceux rencontrés chez les animaux Il est possible de mesurer la façon dont elles appréhendent leur environnement extérieur et la manière dont elles y réagissent. Ces mesures utilisant l’état électrique de la surface des feuilles peuvent être transcris en sons moyennant l’utilisation de matériels adaptés et ouvrent alors la voie à des possibilités de compréhension et d’interaction totalement nouvelles avec les plantes.
https://www.pepiniere-botanique.com/concerts-botaniques.html
https://www.humanosphere.info/2014/09/les-plantes-font-de-la-musique-venez-les-ecouter/ https://www.francebleu.fr/infos/societe/gaujacq-les-plantes-vous-jouent-de-la-musique-1433522704 http://www.sudouest.fr/2015/10/09/landes-decouvrez-la-musique-des-plantes-au-plantarium-de-gaujacq-2149608-3452.php
Acceleromètres https://fr.wikipedia.org/wiki/Acc%C3%A9l%C3%A9rom%C3%A8tre L'accélération vibratoire[modifier
Les accélérations vibratoires sont considérées comme des accélérations de niveau moyen (généralement une centaine de g).
Elles nécessitent un capteur de bande passante allant jusqu'à 10 kHz et de précision de l'ordre de 1 % de l'échelle de mesure du capteur.
Les accéléromètres utilisés, de type non-asservis, sont :
-
à détection piézoélectrique -
à détection piézorésistive ou jauge d'extensométrie -
à détection inductive (ou réluctance variable)
Micromembranes résonantes https://tel.archives-ouvertes.fr/tel-00258395/en/
Détection acoustique des larves xylophages dans le bois
https://hal.archives-ouvertes.fr/hal-00554453/
Measuring vibration https://www.bksv.com/media/doc/br0094.pdf http://www.ni.com/white-paper/3807/en/
Google research term : "plant sound"
cf.Stéphane Douady
Sound Garden: Can Plants Actually Talk and Hear? http://www.livescience.com/27802-plants-trees-talk-with-sound.html
http://passeurdesciences.blog.lemonde.fr/2012/06/13/les-plantes-entendent-elles/ https://gargantua.polytechnique.fr/siatel-web/linkto/?objectId=DOCF0021000001CC000000000000110D00000000
Louis and I pursue our researches and put together our project proposal, although the project seems completely foolish. Several weeks have gone by and we need to get back into the project and find a concrete path to follow. We are still thinking about a piezo sensor. The question of whether or not it would acually be sensitive enough to capture something remains completely open, even more so that internal vibratory plant production seems elusive, limited to certain plants at specific moments such as drought stress.
Our proposition is here : https://drive.google.com/open?id=1phfCsEOTJLYcFH4XENyVGwOY-YmRugIKG3VnI3-fpYc
Saturday and Sunday devoted to research. We still have no idea how this can all come together, and we need to buy parts. The online research gives few clus as to how to actually make something, some kind of circuitry which would actually work. I finally run acroos a project, "Pulsum Plantae", that seems to be very close to what we are looking for, where the artist pursues her idea of plants as forms of bio-sensors, responding to touch, sound, and light. Even moss generates a signal. Their GitHub leaves open many questions. Bribes of ideas, but not enough. I conclude that using an ECG sensor is maybe the trick.
Monday and Tuesday shopping, first to St. Quentin radio (basic parts) and then to HackSpark for the ECG Sensor.
Time passed: 12 hours
Today is the day in class to test our ECG Biosensors. We downloaded the code used with the kit sensor (Arduino and Processing) and plugged everything together. Louis' body served as a baseline ECG measure. It works, but the signal is very noisy. Louis modifies the arduino code to both regulate sampling intervals in order to smooth the signal and at the same time map the signal to predefined tones. I wonder if some kind of low-pass filter (capacitor) could be designed, but this is for later.
We want to have an audio output. I put together a simple amplifier circuit based on an LM386N IC (this circuit needs to be improved) and a small 8W loudspeaker.
Everything works thus far.
After lunch, we buy a plant to begin testing. Our criteria is to have a succulent type plant, ie with an important internal water content, under the belief that this will improve internal conductivity. We choose an Aloe Vera at a local florist.
To our surprise, the plant responds! Or, rather, the ECG signal deviates when moving the branches to which the electrodes are attached. This is a first success, although we have no clear idea of why it works nor of what exactly we are measuring. Some limitations: the plant only responds to direct contact/movement, not changes in sound or light. The questions need to be pursued, as well as refining the circuits. (see photos and video)
Time passed : 8 hours
It occurred to me today that there was something askew using the ECG Biosensors. The ECG uses three cables, but on the Pulsum Plantae board there are only two inputs. And, there is also the inscription on the board, "Galvanico".
More research. In fact, the notion of "biosensor" covers a variety of different methods to capture small electrical signals from biological materials : ECG; EMG, EEG, GSR ...
GSR, or Galvanic Skin Reaction, measures skin conductivity : how much the skin conducts (conductivity) or doesn't (resistance). The two-probe approach and the card inscription "galvanico", suggests this as a method for listening to plants.
The other point is to find acupuncture tools: the Pulsum Plantae project suggests needles for plants such as cactii, and electrode pads which differ from the ECG pads. The only supplier seems to be Phu-Xuan, in the 5th. Needles, magnetic points that could become electrodes (maybe...), plus miscellaneous things like alligator Clips at St Quentin Radio. Time passed : 5 hours, plus arranging Zotero and this journal.
We reassembled the circuit for a new test. The first results are similar to what we’ve already seen. The big question is why it works. Louis finds other docs about “The Bio-Electric Potentials of Plants and Their Functional Significance” and even a Youtube video (links in the bibliography).
We use a multimeter and acupuncture needles to measure the DC voltage between the soil and the plant which gives a positive reading (see photos). Do the plant and the soil act together as a kind of accumulator? What role does the soil humidity play?
Next step. Instead of putting the 3 ECG probes on the plant, we stuff one of them in the soil. We observe a regular cycle, but we need to refine the processing code in order to assign frequency values to the cycle (see photos).
In the afternoon, I work alone. Up until now, we’ve used Louis’ computer. Switching computers gives a surprising result. My computer has a metal back. When I touch the metal surface, the graph changes completely, gaining in amplitude. This suggests a ground fault, but also that the current is passing from the computer through the Arduino, the 8232 card, and then the plant (see photos).
To do:
- repeat the initial experience in a different environment with the least amount of electro-magnetic interference and check results;
- add a common mass as a grounding element for all the components;
- modify the Processing program by adding amplitude and frequency scales.