This kind of ‘secret plant behaviour’ has been researched before in the seventies. A remarkable collection of experiments is summarized in the 1975 publication ‘The Secret Life of Plants’ written by Peter Tompkins and Christopher Bird. The book casts light on the rich psychic universe of plants, and explores among many things their response to human care and nurturing, their reaction to music, ability to communicate with humans, curative powers and even lie-detector abilities. Although these experiments have on many occasions been dismissed as pseudoscience, they do suggest that plants have a richer way of interacting with the environment than is commonly believed.
Inspired by these curious experiments, The Secret Life of Plants experiments at Mediamatic explores the effects of musical stimulation on the well-being of plants. Of course it is impossible for us humans to know if our vegetative companions actually ‘listen’ to the music played to them, let alone whether they particularly like or despise certain genres or songs. Obviously, we as human beings do not have the same senses as plants and therefore will always be constricted to the basic five human senses in which we experience the world around us. However, what we can do is observe how the plants react to the music or, better yet, how plants react to audio vibrations we humans call music.
These vibrations - also referred to as frequencies - can be physically felt, as one experiences standing very close to a loudspeaker at a concert. As audio waves travel through space these vibrations can penetrate the organic cells. And dependent on the frequency level, playtime and repetition of the sound it can either stimulate cell renewal (growth) or cause cell degradation (shrinkage and atrophy). The right music can thus have a positive influence on the growth of plants.
However, this growth can also be related to the process of photosynthesis - a form of biosynthesis in which light energy is used to convert carbon dioxide into among other things carbohydrates such as glucose. While most of the carbohydrates are used by the plant to feed itself, excess carbohydrates (called rhizodeposits) are eaten by bacteria naturally present in the soil. Interestingly, these bacteria produce protons and electrons when consuming the rhizodeposits, thus indicating and converting the plant’s energy production. This implies these plants may be used as a natural source of renewable energy - commonly referred to as a Plant-Microbial-Fuel-Cell (PMFC).
Logically we can state that when the plants grows, more leafy area is formed to receive sunlight, hence more photosynthesis can take place, more nutrients are produced for bacteria to consume, and subsequently more energy is produced. Measuring the voltage and current level is therefore a good indication of the amount of cell renewal or degradation (growth or shrinkage) of a plant.
Naturally, we would like to know and keep under control the energy production’s correlation with other possible changes in the plants’ environment. To identify and closely monitor the latter, we measure on an hourly basis conditions of humidity, light intensity, temperature and soil-humidity.
The plants in the experiments are tested under three conditions. Greenhouse #1 will function as a control group and will be used to compare the results of the other two conditions. This group will be tested in the exact same setting as the others, but in silence. In greenhouse #2, plants are exposed to a variety of classical rock music from the seventies and eighties. Characterized by heavy drums and loud guitars, these songs constitute a counter condition for the one tested in greenhouse #3. In the latter, plants are exposed to Classical Vedic Music originating from India. These songs, called Gandharva Vedas or 'The Eternal Music of Nature', are traditionally played on Gandharva Veda instruments: the flute, violin harmonium, and veena. The aforementioned experiments by Tompkins and Bird, conducted in the seventies, demonstrated that these Vedas have a frequency and decibel that indeed stimulates cell renewal and growth in plants. The plants are exposed to the different musical conditions for 3 hours each day.
Dependent on natural processes, the experiments have to run for at least a month before significant insights can be gained from data correlations. My next blog will elaborate on the first observations and findings as well as diving a bit deeper into the choice of music and the precise mechanics of a PMFC.