Every day thousands of people play with Anish Kapoor’s Cloud Gate in Chicago’s Millennium Park. Affectionately nicknamed “the bean” for obvious reasons, the immense mirrored sculpture is made up of 168 stainless steel plates welded together and placed on the ground. It’s about 10 meters tall, with a base of about 20 by 13 meters. That’s what it takes – smaller is not possible. Such an impressive size is needed for the sculpture to impose itself in the Millennium Park and to achieve the ambition of the project, to play with the light and mix all the reflections of Chicago and its environment, day and night.
It’s striking: the city of Chicago is the right place for Cloud Gate, with a very simple surrounding geography. On one side is the Midwest, the flat American plain over seemingly infinite distances. Unlike France, where the landscape can change completely within just a few kilometres, in the Midwest, you can drive for hours and nothing will change. On the other side of Cloud Gate is Lake Michigan, its surface equivalent to 10% of the area of France. Water goes to the horizon on one side and endless cornfields are on the other. In this flat world, the city’s skyscrapers point to the sky. More than 100 culminate at more than 150 meters, with 442 meters for the highest. At night, it’s just magical.
Cloud Gate is in Millennium Park, between downtown Chicago and Lake Michigan. Depending on the position you take, Cloud Gate is the mirror you choose for yourself. You can mix the elements as you wish: the sky, the city, the space above the lake and, and of course, the skyscrapers. It is gorgeous night or day, when weather is good and when it is not. You can be in the image you construct or not. If you want, you can even walk underneath to hide everything. Thousands of photos on the Web show all the possibilities.
Geometric optics, rules the game with light
Mirrors and lenses are two pillars of geometric optics, the basic tools for changing the direction of light rays. Transmission, reflection and refraction are the associated words. What we want to look at and how we observe determine how we build and assemble these optical elements. Professionals of this game are astronomers and microscopists. Anish Kapoor does the very same thing with Cloud Gate. But anyone who plays with light does not do so without consequences. Light brings into our eyes pictorial information about the world at the speed… of light. Having this information, seeing it, determines our lives. Nothing less.
Mirrors and lenses allow us to see at different scales: from the infinitely large with the Hubble Space Telescope to the invisibly small all around us with optical microscopes. Imaging at different scales has always been one of the major issues in science. Anish Kapoor approached sculpture with this idea, so he ended up building curved mirrors. This is no surprise for a physicist, but what Kapoor does with it artistically is amazing. Say why with a physicist’s eyes is the subject of this article.
Galileo’s telescope changes the view of the universe
The most famous example of this game, in which one looks beyond the visible with an optical instrument, is the observation of the surface of the Moon with a telescope by Galileo in 1609. Two references help to situate the importance of the event. First of all, in the 1610 treatise “Sidereus Nuncius” (Messenger of the Stars), Galileo makes it evident at the very first page:
“Great, certainly, are the subjects that in this thin treatise I propose to each of those who observe Nature, so that they examine and contemplate them. Great, I say, first because of the importance of matter itself, then because of its unprecedented novelty over the centuries, finally, also because of the Instrument through which these subjects have offered themselves to our perception.”
As an experimental physicist, I particularly appreciate the capital I of the word instrument. As a teacher, I have always noted the phrase “are offered to our perception”. The result of the observation, in other words, is that any viewer in Galileo’s time, even one previously convinced that the Moon is an ideal celestial sphere, would see it like the Earth, “covered on all sides with enormous protuberances, deep hollows, and sinuosities”. Too late, you should not have looked… Believe what you may, but with one look at the Moon with a telescope, and it will immediately lose its status as the ideal sphere to become like the Earth itself. Your vision of the world and the universe will be irremediably transformed, as Galileo emphasised in his book.
The philosopher Hannah Arendt, in The Human Condition, underlines the radical break that this Galileo experience introduces. For her, three events founded modernity: the discovery by Europeans of the New World, the Reformation and the invention of the astronomical telescope:
“What Galileo did and what nobody had done before was to use the telescope in such a way that the secrets of the universe were delivered to human cognition ‘with the certainty of sense-perception’, that is, he put within the grasp of an earth-bound creature and its body-bound senses what had seemed forever beyond his reach, at best open to the uncertainties of speculation and imagination.”
We do not play with light with impunity – it opens doors and transports us far away. Today, the images of the Hubble telescope show us the incredible diversity of deep space.
With Cloud Gate of Anish Kapoor, a return to Earth
In this context, which combines the technical capacity of observation and its overwhelming implications for our vision of our situation on Earth and in the universe, how can Anish Kapoor’s mirror sculpture be approached? In “I have nothing to say”, Anish Kapoor insists on the link between his mirrors and their place of installation, the space they open by deciphering the world around them.
Chicago, with its elementary geography of an immense plain, lake and magnificent man-made urban landscape, is made for Cloud Gate. The sculpture, in a dialogue with the skyscrapers that create verticality in this flat space, is an instrument that allows everyone to play with light to propose all the mixtures, all the distortions, all the reconstructions of this landscape. It is a new scope, which, by distortion and dilatation, changes how we see us in the world. This sculpture processes the elements of the landscape around the viewer, and changes his or her perception. The Skyline is now in front of us. We are in immediate proximity with the massive buildings behind Michigan Avenue. This new kind of scale focuses our attention on what is immediately around us.
The contrast with Hannah Arendt’s analysis of Galileo’s observation of the Moon and its bezel is radical:
“We always handle nature from a point in the universe outside the earth. Without actually standing where Archimedes wished to stand, still bound to the earth through the human condition, we have found a way to act on the earth and within terrestrial nature as though we dispose of it from outside, from the Archimedean point. And even at the risk of endangering the natural life process we expose the earth to universal, cosmic forces alien to nature’s household.”
You don’t play with light without consequences…
We’re now back on Earth, but times have changed. With the exception of Elon Musk, perhaps, we all now know our planet is a finite one and the only one.
Sculpting one’s environment
In its simplicity, Cloud Gate is just a giant mirror, after all. Its curved shape provides all kinds of mirrors with different curves and viewing angles. This is how everyone builds their own image of Chicago. Unlike Galileo’s telescope, the viewer sets up his or her own presence, choosing a place and that of others during the construction of the image. For a moment, we all becomes sculptors of our own environment and its ephemeral representation. And one day I will have to write how the discovery of exoplanets is again changing everything… after an artist seizes it.
Joel Chevrier, Professeur de physique, Université Grenoble Alpes
Cet article est republié à partir de The Conversation sous licence Creative Commons. Lire l’article original.