Seeing the Invisible

Illustrasjon: Linn Hovde Hestnes

There are several motions our naked eye cannot observe, and they surround us on a daily basis. Movement of sound and light waves, pressure and vibration, and the energy that is essential for every living creature; the machinery of the body. 

This machinery consists of the heart, an engine that creates energy through the hearts motion, consequently pushing the blood through our vessels, creating warmth and oxygen to the circulatory system. To make the unobservable motion observable to the naked eye, technology and machines can be applied, but who devised these methods? Moreover, how were scientific methods applied to visualize previously unobservable phenomenon? 

The French physician and physiologist, Etienne-Jules Marey (1830–1904), saw his passion in documenting and making movement observable. With an extreme interest within machinery and physics, Marey investigated the body as «a human machinery», and saw the opportunity to read and map the body to get a better understanding of the different forces that control humans. Marey’s scientific investigation, was precisely movement, which he saw as a characteristic of life. 

Throughout history there has been many scientific approaches for observing, storing and documenting data, as well as recordings, which have been predecessors of our everyday technology today. Especially in the medical field, but also in the art and movie industry. It is interesting to see how it is possible to translate the energy around us into specific visualizations. In picturing time, space and movement, Etienne-Jules Marey played a central role. Marey’s interest in machinery and science would give us the ability to see the invisible, as well as developing and perfect the predecessors to some of the medical devices used in modern days hospital around the world today.

The human machinery and the natural force

In his early days as a medicine student, Marey turned towards the field of human mechanics, cardiology and blood circulation. He wanted to explain the mechanisms of the heart and blood vessels and shed some light upon the purely mechanical process of the circulatory system. Marey believed there was a life process that an intelligible causality could be measured, and also make the physiology field an exact science, like physics and chemistry. These life processes meant the natural «laws», which are the natural forces later named «energy», were causes and manifestations of the phenomenon we observe. The phenomenon of the unobservable force. This brings us to the scientific field of the nineteenth century, positivism, and the discovery and principle of the conservation of energy. The principle of conserving energy proved that energy itself can be neither created nor destroyed. Energy could only be transformed through different forms. This led to a new symbolization of nature; motion, dynamics and energy.

The invisible

Energy, the often invisible force, is vital to our body. It facilitates pressure that pulsates from the heart, through the blood arteries, and allows us to remain warm and alive. The pressure inside our blood vessels is not visible to us, other than the brief pulse at the surface of the skin. With a stethoscope, and thorough sound waves, it is possible to hear this energy within the body, demonstrating the translatable qualities of energy. A healthy body produces a firm, rhythmic movement, representing the hearts muscular aspect, but also its symbolic value as the vital organ sustaining life. By capturing the movement of a radialis pulse, it is possible to draw and picture life itself. 

Picturing life is partly picturing the human mechanics, and expanding the knowledge concerning how our bodies function. Therefore, it is possible to make life itself visible. In the same way as capturing sound waves, it is possible to make sound visible. It is possible to categorize vibration and energy, time and space into movement, a field which Etienne-Jules Marey made his speciality. But how is it possible to capture the invisible? What is capable to capture and depict the natural force of nature? Etienne-Jules Marey’s answer was machines. 

Illustrasjon: Linn Hovde Hestnes

The graphic instrument

As the principle of energy was well known when Marey started his career, it led him to the development of an instrument which could trace and make a graphic presentation of movement within the body. But capturing these delicate movements would prove to be difficult, as most of them are imperceptible to humans and have an intricacy. The intricacy of regularity, duration and amplitude were challenging to record and properly visualize on paper. An instrument would therefore have to be made in a way, where it would not interfere with the motions it was designed to measure. The complexity of the motions had to be made visible, also including their temporal, as well as spatial dimensions. The recordings of the results had to be written down in a permanent form, to enable analysis between measurements and subjects. Instruments which depicted change over time, were not a new invention in the mid-nineteen hundreds. Graphical inscriptors developed for physics started to emerge in the physiological field.

In order to understand the machinery of the body, Marey had to construct an apparatus which would mechanically translate the organs energy, and make this energy visible. As other inventors before him, Marey’s apparatus made a graphical description and recordings of pressure. This graphical invention was a development based on the first graphing instrument within the physiology field, the kymograph, which was placed inside the body of an animal. Marey’s invention, on the other hand, was not placed inside the body, but on the outside. The graphing instrument could measure rapid movements and capture its temporal context. Marey named the instrument the sphygmograph. The sphygmograph was an automatic pulse writer, which led Marey to create a language of time and motion. Marey’s invention was one of the most important contributions to the cardiologic field, and would later lead to other medical inventions, like the electrocardiogram.

By introducing a new and accurate way of recording bodily movement, the sphygmograph would usher in a modern understanding of the human body to the scientific field. Providing the opportunity to trace movement within the body, Marey showed that the machines could go beyond the human perception. Marey’s instrument made it possible to collect data about what was sensed. This data was what the instrument saw, touched and heard, but also traced in relation to time and space, like the «the essence of motion»19, and again made the invisible life and language visible. The machines has the ability to make that which to us is invisible, visible. By visualizing these previously invisible aspects of life, a world of previously unknown and not accessible, present itself. Like recreating nature’s mechanical movement, transforming it into machines enabling an easier, healthier life. To understand muscle activities, and how the animal mechanism works, we can see what must be done to ensure that nature’s creatures perform as best as they can. 

Litteratur:

Dagognet, François. Etienne-Jules Marey: A passion for the Trace. Translated by Robert Galeta with Jeanine Herman. New York: Urzone Inc., 1992.

Braun, Marta. Picturing Time: The Work of Etienne-Jules Marey (1830–1904). Chicago: The University of Chicago Press, 1992.

Lüderitz, Berndt. «History: Etienne-Jules Marey (1830–1904)». Journal of Interventional Cardiac Electrophysiology, 12 (2005): 91–92. 09.11.20. DOI: 10.1007/s1084+-005-

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