610 likes | 738 Vues
Tilting at Windmills. A Reading of a Wind Turbine By Charlotte Ebel. At the Teachers as Scholars Institute held at Princeton in 2005, Professor Michael S. Mahoney challenged the participants to engage in a process that he called “reading a machine.”. Introduction.
E N D
Tilting at Windmills A Reading of a Wind Turbine By Charlotte Ebel
At the Teachers as Scholars Institute held at Princeton in 2005, Professor Michael S. Mahoney challenged the participants to engage in a process that he called “reading a machine.” Introduction
In the opening paragraph of his article by that name, he quoted the title of a paper presented by R.W. Hamming at the International Conference on the History of Computing in 1976: “We would know what they thought when they did it.”
“That notion,” I could say, parroting Mahoney, “took some time to penetrate my literary instincts.” What I Thought When I Did It
It’s not that I feared objects. I have always been comfortable with them and collected far too many of them. I’m more mechanical than many women. I can change a tire, fix a vacuum cleaner or a washing machine, even open up the butterfly valve of my old Ford Mustang when it sticks. I am not afraid to tinker with my computer.
But my literary instincts were so strong to overcome. My whole, long career has been explicating texts, parsing sentences, scanning poems, analyzing statutes, “mining” judicial opinions.
Words are my nuts, bolts, transmissions, motors, governors, pulleys, ailerons, but when it comes to machines, my curiosity surpasses my ken. I suppose it would not be true curiosity if it were not so. What I mean is this is both my strength and my weakness.
Mahoney goes on to elucidate in his article the point that the practice of science and the literature of science do not necessarily coincide. He avers that early in his career, he had “cast about for the primary sources of technology since the Renaissance,” a quest which he discontinued when he realized that “the great ideas we were seeking did not lie in books. They lay in objects.”
Having enjoyed a preview of the course, I had long thought about it and formulated the idea that I wanted to study the Lemieux brothers early work in film production. I later discarded the idea, thinking, because of the published title of the course, that we would be obliged to choose a scientist, inventor, or object more closely related to American history.
I then thought of wind turbines since this alternative form of energy is a topic that has interested me for several years. And later, when the course had begun, a humorous aside by the professor planted the idea that I, a French teacher, might investigate the guillotine.
I would choose the one for which materials were easily accessible, and eureka! The first trip to the library stacks produced what seemed to be just the right books to do the “reading” on the guillotine.
They practically flew off the shelf into my hands with titles promising answers to the central questions of the exercise. As I perused them, the characters, the drama, the history, the moral issues came spilling out and flooded my mind with scenes that I knew well. I would undoubtedly glean some juicy details to take back to my French classes.
However, as I thought of it in the context of the “machine readings” we had done in class, the guillotine seemed less interesting. Where would I find a model this side of France? It lacked the myriad “quotations” that even I could recognize in the wind turbine, but would I ever be able to attribute them all? And I had no model for the wind turbine either.
It was in the summer of 1988 when my family on the return leg of a cross-country trip rolled from the top of a hill into the valley of Altamont in California and there they were, like so any sentinels.
We were awed by their height, enchanted by their grace, mesmerized by their sound – a whir, a whoosh, a blade cutting air, but not as its sharp severance by a sword, rather like a graceful diver cutting through the surface of the water.
I thought of a line in a book I used to read the children, Gilberto and the Wind: “Who has seen the wind? Neither you nor I. But when the leaves blow down the street, the wind is passing by.” Marie Hall Ets, Gilberto and the Wind
No leaves on this treeless plain, but still one knew the wind was passing by from the rhythmical cosmic whisper of these turbines.
We wanted to think then that it was the wind telling us of some magical future when the production of energy no longer polluted our atmosphere but instead gave us elegant machines that through their rhythmic gymnastics unfurled a stream of wind-borne electricity to power our lives.
Now in this course, I ask myself how they came to be, these turbines. Their obvious antecedents were the windmills.
my fascination with Dutch windmills when I read Hans Brinker, or the Silver Skates. I thought about . . .
dear old Daudet writing in his windmill in Provence. I thought about . . .
Don Quixote • jousting with • Windmills. I thought about . . .
. . . when I tilted with windmills, • when I tried to “read” – from an image, no less – • a wind turbine, a modern windmill.
A typical height for a commercial turbine tower is about 230 feet.
The door allows access to an interior ladder. • One may ascend the tower from the inside to perform maintenance. There is a door in the base of the tower.
It encases the engine. • It is about the size of a small school bus. At the top of the tower is the nacelle.
This model has three blades. The blades are very smooth so that the wind may pass easily over them. They are very strong so as not to break in the wind. They are aerodynamic in design. They are connected to a shaft that turns the dynamo inside the nacelle. On the front of the nacelle is the rotor.
Here we see the enormous size and the aeronautical design of a rotor and blades.
The blades are routinely washed to keep them clean. Any cracks are filled to keep them smooth.
The blades scoop up the wind and use its power to turn the gears. The gears make the high speed shaft turn approx. 50x faster than the low-speed shaft. The high-speed shaft turns the dynamo to produce electricity. If the wind speed becomes too fast, the controller computer shuts down the turbine. A cooling mechanism keeps the generator from overheating while it is working so fast. The yaw mechanism orients the rotor to the wind. What’s happening?
This model turbine is very expensive and complex. It is intended for use by a commercial supplier, such as an electric company. It is part of a system.
These large installations are called wind farms. Notice that the wind turbines in this picture have lattice towers.
The turbines connect to a grid that will transmit the electricity to the consumer.
A 1,500-watt wind turbine provides this home in Colorado with electricity. Credit: Jim Green Some of the documents on this page are available as Adobe Acrobat PDFs.Download Acrobat Reader Some consumers, especially in remote locations, install small wind turbines to serve their residence individually.
Environmental Concerns • Birds • Noise • Visual • Climate • Land Use
Reflections On reading a machine
This project has undergone numerous transmogrifications during the two weeks of the Teachers as Scholars Seminar. Each day Aeolus seemed to release research winds from a different direction. I sometimes doubted the ability of my brain to yaw sufficiently in the right direction.
On the last day of class before presentations, two remarks collided with a scene I had observed on the previous day’s field trip to the National Museum of History and created a spark that illuminated a creed I have long held.