See SeventhCities for finished product
Renaissance and Pre-Geometry
Perspective
This is an integrated unit on the Renaissance in Social Studies, Geometry in
math, and Photoshop on Computer. I will speak first on the Perspective Drawing,
Art, Geometry and Computer part of the unit. I am going to explain how my students
created these drawings in order to explain how we teach them to think about
the Renaissance. I teach perspective drawing and the computer project in order
to
give boys a Renaissance experience while at the same time preparing them for
geometry. As perspective art in the Renaissance led to Toscanelli’s perspective
map of the earth which Columbus persuasively used to sail west, our perspective
geometry project leads to creative art done while thinking, reading and writing
about Renaissance history.
It all begins with the horizon line. When we gaze out to sea and ocean meets
sky, the horizon just is. When we direct our gaze to a vanishing point, that
is an aesthetic as well as practical act. When we turn our heads to create
two vanishing points at each end of the horizon, to differentiate foreground
from
background, that is a mathematical as well as aesthetic act. The horizon line
and vanishing point placement in a drawing create the point of view, an echo
of the Renaissance humanist belief that man “is the measure of all things” from
art to maps of a round earth drawn on flat paper.
Our project begins with rectangular solid drawn in one-point perspective:
Overhead #1.
Notice how vanishing lines determine the sides of the solid; the
back vertical edge is artist’s choice.
Overhead #2.
The box above, and the box below the line of horizon.
Overhead #3
Next, students draw a cube below the horizon line, in two-point perspective.
Now lines to the vanishing points create the angles at which the sides and back
vertical edges are drawn. The vertical edges are still drawn vertically on paper.
Lines parallel to the horizon remain parallel.
The vertical front edge, horizon line and placement of the vanishing points are
aesthetic decisions. But from there angles of the sides belong to the geometry
of mathematics. The point of view demands the mathematical precision of the draftsman.
If an object, building or city skyline is to be drawn so close to the viewer
that part is below the horizon and part is above, some city scape axioms, or
rules are required to keep the drawing in perspective.
Just as Isaac Asimov had three laws for robotics in “I, Robot,” here
are Mr.McSpadden’s 3 Laws for drawing cityscapes.
Overhead for Rules
1. There is one horizon line with two vanishing points.
2. All vertical lines remain vertical. Lines perpendicular to the horizon line
remain perpendicular.
3. All other lines are drawn to one or the other vanishing points, with two notable
exceptions:
a) Any naturally curved line, such as the curve of a sphere is foreshortened,
and
b) Any naturally angled-line such as the side edge of a pyramid is drawn with
a different angle in perspective drawing.
There it is: a closed system with only three postulates, from which all lines
may be derived. Notice, “derived,” not “solved.” Only
three rules and yet the devil lies in those details. Our correct method for solving
the problems posed by # 3 is trial-and-error: what “looks right” by
comparing the drawing to the skyline of SF outside our window. Thus, an intuitive
aesthetic judgment is used to induce a mathematical system. “Leonardo da
Vinci once began one of his writings on painting by saying,” Let no one
who is not a mathematician read my works.’” (M. Serra, Discovering
Geometry)
Since our school is on a San Francisco hill with views of the Golden Gate Bridge,
bay, and city, my students are quite familiar with a city skyline. What “looks
right” on paper is easily held up the window for real perspective views.
What precede all this is some science lessons on the eye, and how we see. Throughout
this process, the question is posed to the boys: “How do you draw a true
line on paper?”
Overhead #4 Kentaro
Overhead#5 Luke
This project is the precursor, the set of experiences that prepare the boys
for the five postulates of Euclid and deductive reasoning of geometric proofs.
The “Common
Notions” of Euclid are taught in beginning algebra. One example of Euclid’s
common notion is the reflexive property: two things both equal to a third must
equal each other. From the postulates, “assumed to be true without proof”,
the basic constructions of line and angle bisectors, perpendicular bisectors,
construction of parallel lines, and so on, theorems are systematically developed
through logical proofs that then lead to further theorems. Such a mathematical
system demands some prior experience and prerequisite knowledge. This project
of a true line drawn with 3 simple rules is a simpliflied structure of the
rigorous logic of formal geometry.
The 12-year olds who while studying the Renaissance make their own perspective
drawings will continue with pre-algebra. As 13-year olds they will study beginning
algebra through the quadratic equation.
Concurrently, half of the 8th grade class studies hands-on, inductive geometry,
using Michael Serra’s Discovering Geometry (Key Curriculum Press, Berkeley).
Serra uses a transparent square of paper that he calls patty-paper those folds
as origami paper. Patty-paper begins with its own postulates borrowed from
Euclid and expanded:
Any two figures on separate patty-papers that fit exactly on top of one another
are declared to be congruent without proof.
All students begin with a common but different given, such as 30 differently
sized and shaped acute scalene triangles, proceed through steps, and then make
a generalization based on common results with no contradiction. These demonstrations
of theorems are called conjectures until formally proved (Euclid). The boys then
go to high schools that place then into year of either inductive or deductive
geometry, depending on placement tests.
It was Alberti, who wrote the book on how to paint in Renaissance perspective,
who gave us the rectangular grid to aid the foreshortening of perspective.
The ideas were certainly used by many renaissance painters, to say nothing
of Toscanelli
and his map, which Columbus carried to the new world. I must give credit to
James Burke, for his film, “Point of View” in the excellent series, “The
Day the Universe Changed”. His film made the first connection that I was
aware of between Alberti, Renaissance painter and writer, Toscanelli, supreme
problem-solver, Brunelleschi, architect of the dome in Florence, and Columbus.
On gridded paper or graph paper, drawing horizontal lines to a vanishing point
focuses the boys’ attention on perspective. It is the drawing of a city,
line after line, window after window, building after building, which reinforces
the necessity of a closed system of rules which breaks up the grid into the
perspective of distance as seen by the eye that creates the readiness for geometry.
This
discovery method is one way of preparing boys for the logic of postulates that
lead to theorems.
FOR GEOMETRY TEACHERS
As a young naïve banker and teacher I was puzzled by people who didn’t “get” the
logical system of geometry or algebra. Memorize the postulates; understand them
and their constructions and you could puzzle out the proofs. Using some guess
and check, logical deduction and construction you had a reasonable chance of
working out the proof. What I realized later was that in trying to oversimplify
algebra or geometry into rote repetition rules, for many people any new problem
was a “gotcha”. It was difficult to teach that hard thinking had
to precede the practice that led to mastery. For many people mindless repeats
of the arithmetic, math, or algebra algorithm didn’t lead to successful
learning or understanding. For some people, no matter how many trees they examined,
they could never conceptually leap to the abstract idea of forest. In Euclid’s
geometry one starts with forest and constructs the meaning tree by tree. This
project is a scale model of a forest: learn three simple rules and apply them
over and over until system mastery results. Euclid’s achievement is often
unrecognized or neglected. His formal deductive system was a great accomplishment
of western civilization. Even today, the best geometry texts and teaching methods
are those that stay truest to Euclid.
The pedagogic problem is that Euclid demands a high level of readiness, both
in mathematics and in intellectual rigor. Most modern geometry programs teach
the readiness and small bits of Euclid, and ignore the intellectual, logical
mindset that Euclid and geometry demand.
Michael Serra’s Discovering Geometry uses an inductive approach for the
first semester, giving proofs by construction demonstrations, and then moving
students into Euclid’s logic. It also has exercises is deductive logic
to prepare students for proofs.
Trial-and-error, guess and check, are both ways of moving the furniture around
in the den. Understanding spatial relationships and how 3-d space relates to
2-d paper drawings is a better way, especially if you happen to be the one moving
the couch.
This problem forces boys to learn the system (postulates) first; then apply
them over and over. You can draw a city skyline using only verticals and lines
drawn
to the vanishing points, (rules one and two) but it has all the excitement
of the skyline of Peoria, Illinois. By exploring the exceptions, rule 3, the
boys
are led to ponder, “How do you make new rules (theorems) in a closed system?” It
is this thinking that prepares boys for geometry.
Mathematics is probably the worst of all subjects for ignoring its own world
history. Even the best math texts present problems as if they were just created
the night before, with no context or meaning. This is an attempt to create
a math problem, perspective drawing, following three simple rules, that has
a historical
context, and was very real at the time. Nowhere in the modern math curriculum
is problem-solving given a course of its own. The NCTM definition of problem-solving
is “what you do when you don’t even know where to start”. Problems
in real life are often like that. I don’t mean math courses where the odd-numbered “problems” are
answered in the back of the book. Such exercises are necessary, but not problem-solving.
Problem-solving means using mathematics to create further meaning in the context
of a real world situation. Creating your own city-view in two-point perspective
is a Renaissance and a modern problem, something city planners have not achieved
either. Problem-solving demands bringing all knowledge to the effort, and what
a better model for that than Renaissance men who acted as if art, science, and
mathematics, architecture, map drawing were all one subject to be tackled. Problem-solving
demands some life experience to be brought to bear on the task. But how do you
gain the necessary patience, endure the frustration, acquire persistence or determination?
All too often I have dealt with upper middle-class parents who insisted that
their sons be held on track to become executive problem-solvers—but along
the way insist that their own sons not encounter any real- life problems. Where
do you get the practical knowledge that may give you clues?
I have a student in my advisory that is both delightful and imaginative- yet
he is programmed from morning until night. After school he has fencing practice,
saxophone lessons, and language lessons. Throw in soccer practices and games,
drama in spring, and he is busy until 7pm nightly and all day Saturdays. With
the academic load of Stuart Hall, he is often busy nightly until 10pm. Yet
his scheduled life is all too typical of most Stuart Hall boys. In my Friday
morning
advisory period, he and a friend are allowed 15 minutes to “play” a
game of their choice. It’s his only weekly free time.
Some where in my childhood between electric trains, building models, reading
maps at boy scout camp, and a student job in a kitchen cabinet shop, I acquired
the prior knowledge or experience of angles, measurement, and similarity, that
made geometry proofs seem logical and easy to progress through. What kind of “play” leads
to Euclid? Where do modern boys, in their programmed lives, whose amusements
are video games, discover knowledge of right angles? What experiences are they
having that will make Euclid achievable without instant amnesia after the final?
When my students have successfully completed a line drawing of a city skyline
in two-point perspective, with me as final arbiter of “correctness”,
Illustration B&W city line drawing
they then scan it into the Mac computers using “PhotoShop” software.
It is at this point the Renaissance project and major conceit begins: Students
are to color their cities, and then change them completely. As Renaissance artists
changed from the medieval God’s eye view of the world to a humanist one,
so are modern boys to use the computer to change their universe. The challenge
is, “If you could see the world a different way, how would you see it?” Modern
boys have the advantage of 400 years of art history and styles to emulate,
and the break-up that is at the core of much modern art. The only other stipulation
is that no two renderings can be alike.
Boys now get a further insight into the nature of real problem-solving. One
often has to solve a series of sub-problems to discover the real nature of
the real
problem. Now the boys have a new problem: they have had introductory classes
on Photoshop, but never at this deep level. Now they have to master a new logical
system to begin to discover how they will change their world. PhotoShop rules
are a good metaphor of how the system of geometry allows you to see interior
design, architecture, city planning, and common forms in a different, new way.
Good interior designers, good architects, good contractors have an “insight” into
space. They can see flow, focus, harmony of proportions—which is simply
geometry applied.
In creating new city skylines, boys scan in their own black-and-white cityscapes
and they create a new background layer which they then color. Each new color
may be a new layer; each effect or change requires a new layer created and saved.
To get to the finished products you will see shortly may require 20 or more layers.
Also, as layers are saved, boys begin to eye the results critically. To return
to a previous state, boys simply delete the last layer. Any art that results
from their efforts, even if accidentally achieved, requires severe editing of
the layers of unsuccessful effects.
PhotoShop layers, saved and piled on top of each other, represent another logically
closed system. It proceeds from givens, definitions, but allows infinite possibilities.
No matter how imaginatively PhotoShop commands are applied, they are saved
and preserved by a structured language logically applied. The mathematics behind
the art is deeply buried, but clearly there. But once students can control
some
possibilities in PhotoShop, of color, form, and texture, there is still the
problem of changing the universe into many versions, and than aesthetically
choosing
one for final submission. Layers upon layers of possibilities begin to pile
up as boys spend hours in the computer lab. Even when a boy chooses an abstract
manipulation as his best art, it began as a logical construct scanned as a
postulate
into a system—a core of geometry. I make every boy do his project layer
by layer so that I can see its history to help him gain the “insight “of
geometry. Why study the Renaissance during history to do a geometry project
on computer?
Imagine the astonishment of a Lorenzo Medici being told after he was stabbed
in the Cathedral during Mass that he was living in a “rebirth”. Imagine
the astonishment of a Cellini, fighting duels, suffering agony from a sexually-transmitted
disease, arguing with customers and patrons alike, that he was living in a time
famous in history. There is not much in the Autobiography of Benevenuto Cellini
that one can offer a 12 –year old to emulate, yet his art remains, a master
of molds. What was it to be a Renaissance man or woman and yet never know what
exactly was special about the age, except perhaps that some were living a life
as good as the ancient Romans, ”a good, human life”.
Yet what was the Renaissance? Constant war between city-states, assassinations,
economic intrigue and warfare, sexually transmitted plagues without cures, scandals
and corruption
In the Church, and yet that sounds exactly like today’s news.
In Orson Welles’ “The Third Man,” the character Harry Lime
remarks that Switzerland had 400 years of peace and produced only cheese and
cuckoo clocks, while Italy, having political, social, religious and economic
upheaval, gave us the Renaissance.
It wasn’t until 200 years later that the term “renaissance” was
applied to the period and the city of Florence. Two hundred years from now, how
will historians view Silicon Valley and the personal computer with Internet connection?
If you were living in a Golden Age, how would you know? If you were the late
SF newspaper columnist Herb Caen, would you be surprised to keep meeting people
who insisted that “now” was the Golden Decade of San Francisco—and
that happened to Herb Caen for over 60 years?
The conceit is that boys were using computers to emulate the humanist spirit
of the Renaissance: seeing the world in a different way. To extend the conceit,
perhaps someday the personal computer will be viewed as the beginning of some
period of history YET TO BE NAMED. Yet many modern boys are as overworked as
any apprentice boys of the 1400s. The spirit of creativity seems more akin
to play than work, although great solutions or inventions usually require copious
amounts of both. Mathematicians, scientists, and artists all “play” with
their problems. So view this slideshow not just as pre-geometry or as neo-renaissance
project art, but as 12 year olds in directed play—a “play” that
must precede actual learning.
Example of student writing for Renaissance Project