Memoirs of a Blower

BY BERNARD ZUBROVVSKI

Reprinted from Technology Review, Volume 85, Number 8, Nov/Dec 1982 Copyright 1982, Alumni Association of the Massachusetts Institute of Technolgy, Cambridge, Massachusetts 02139 EDUCATION A SPECIAL REPORT

Memoirs

N teaching science to children, I have dren go a step further by creating three- found that the best topics are those dimensional clusters of bubbles that rise I that are equally fascinating to chil• up a plexiglass tube. These bubbles are dren and adults alike. And learning is not as regular as those in the honeycomb most enjoyable when teacher and students formation, but closer observation reveals are exploring together. Blowing bubbles that they have a definite : four provides just such qualities. bubbles (and never more than four) are Bubble blowing is an exciting and fruit• usually in direct contact with one another, ful way for children to develop basic in• with their meeting at a vertex at tuition in science and . And angles of about 109 degrees. And each working with bubbles has prompted me to of a bubble in the cluster will have roughly the wander into various scientific realms such same number of sides, a fact that turns out as , cellular , topol• to be scientifically significant. ogy, and architecture. Bubbles and Bubble In the 1940s, E.B. Matzke, a well- films are also aesthetically appealing, and known botanist who experimented with the children and I have discovered bubbles bubbles, discovered that bubbles in an to be ideal for making sculptures. In fact, array have an average of 14 sides. That is, looking over the past ten years I can see a Blower the "average" bubble has the shape of a certain philosophy emerging—a sort of 14-sided polyhedron. And that's impor• Zen and the art of bubble blowing. tant because 14 is the number of faces of BY BERNARD ZUBRQWSKI the so-called "Kelvin cell." Proposed by in Bubbles Lord Kelvin in the late 1880s, this is the Shimmering ideal geometric shape for enclosing space, Adults tend to think of bubbles as a visual and intricate as they grow requiring the minimum surface and phenomenon, but I suspect children are tension to enclose a given volume. initially more intrigued by their kinetic and change, soap bubbles This may seem to be another of those qualities. is very sensual as it fascinate nearly everyone. esoteric facts scientists bandy about, yet it expands, moving like Jello, sometimes bears on a wide range of structures. For with the entire bubble swaying from side And example, scientists have noted a consistent to side. In the film itself, amoebalike spots blowing bubbles is a rich similarity between soap-bubble arrays and swim through stratified layers of brilliant such diverse things as human fat cells, . And there is a special quality— but overlooked approach to plant cells, cells of dragonfly wings, spots artistic? scientific?—in the way bubbles Imrning, providing insights on a giraffe, cracks in dried mud, the way clump together. Though they seem to have lead shot compacts, and the granular an intricate complexity, the bubbles in a in trom structure of metals. Peter Pearce, in Struc• cluster actually take only two basic the perceptual to ture in Nature Is a Strategy for Design, geometric configurations. the philasophieal. says that soap-bubble arrays "can be Such bubble behavior is featured in ex• taken as the model or type of all hibits I've developed at the Children's systems—biological, physical, chemical— Museum in Boston. In one exhibit, chil• BERNARD ZUBROWSKI is on the staff of the in which there is an economical associa• dren generate a froth of bubbles between Children's Museum in Boston. He holds an tion of cellular modules." What I hope M.S.T. in chemistry and education from Boston two plexiglass sheets spaced half an inch children will gain from playing with bub• College and is the author of numerous books apart. The bubbles form a two- bles is the realization that there are many that describe science experiments using house• patterns in both natural and human-made dimensional hexagonal array similar to a hold materials. Water Pumps and Syphons honeycomb, with three bubble surfaces (Little, Brown, 1981) won the New York phenomena, and that discovering and ex• always meeting along a line at angles of Academy of Sciences' 1982 award as the best plaining such patterns is a vital part of 120 degrees. In another exhibit, the chil- science book for young children. science.

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Children "at work" at the arrays, such as the simple Children's Museum in Bos• cluster above, as struc• ton. Soap bubbles provide tural models. The Pneu vivid examples of many Dome (left) is an early geometric shapes and product of Crysalis Corp., spark discussions of designed for those who mathematical concepts. want a bubble in their Architects also use bubble backyard. EDUCATION A SPECIAL REPORT

Architects have also capitalized on ment. The shapes that bubbles take are Though I am sure she could not have ex• bubbles as what Pearce calls "an elegant similar enough to encourage the search for plained exactly what she had generated, demonstration of minimal principles." patterns, yet they are always different her face and gestures indicated deep con• (Bees, nature's superb architects, demon• enough to arouse anticipation. These centration and satisfaction. strate minimal principles at work: the properties prove to be irresistable to configuration of a honeycomb contains almost everyone, from children in African Geometry in Action the greatest amount of honey with the villages to those in suburban Boston. The least amount of beeswax and requires the educational value is that the material, not On a conceptual level, bubbles can help least energy to construct.) Frei Otto of the teacher, is the motivator. This doesn't illustrate a variety of mathematical rela• Germany is a pioneer in this field, with negate the teacher's role, but suggests that tionships. In fact, mathematicians have numerous bubble-inspired structures to here is something worth exploring for its studied the principles governing the his credit: large balloonlike buildings and own sake. geometry of soap films for at least two huge tents with sweeping lines. Although These qualities were dramatized for me centuries. For younger children, bubbles Otto doesn't simply build a scaled-up as I blew bubbles with a blind child. He and their arrays serve as vivid examples of version of a small bubble array, he finds would wet one hand with soapy film and many geometric shapes, such as the soap-film models useful in determining then, by blowing through a straw, would , hemisphere, pentagon, and hexa• such things as the area form a bubble on his hand. He could sense gon. Creating and feeling these shapes is and the stresses that will occur in his when the bubble began forming and how much more dramatic than simply seeing structures. Indeed, "bubbles" are becom• big it grew. And when it broke, the warm them portrayed two-dimensionally in a ing an increasingly familiar sight in many air in the bubble would disperse—a clear drawing. With older children, bubbles will cities, with tennis courts and other athletic indication that it was gone. The boy grew spark discussions of concepts such as an• facilities sporting air-supported domes excited each time a bubble expanded to gles, surface areas, perimeters, and vol• based on the structure of bubble arrays. cover his hand, and afterward he umes of various geometric shapes. For So soap bubbles are useful in understand• exclaimed that he had never experienced example, by making a bubble grow larger ing structural arrangements from the bubbles so large. they can begin to see the relationship be• micro to the macro. In another instance, I videotaped chil• tween volume and diameter—often a dif• dren playing with the exhibits in the Chil• ficult concept to convey—and they can Lessons to See and Feel dren's Museum and observed a girl who make direct measurements to confirm spent 45 minutes with the same contrap• their observations. Having played with bubbles for so long tion. It was simply some sticks and string Indeed, I feel a bubbles "curriculum" with children, I am convinced that edu• that, when pulled out of the soapy water, could be developed that would span the cators are overlooking a rich opportunity. made a two-by-three-foot film. I discov• educational time line from preschool to Manipulating soap films involves both the ered that the girl developed a repertoire of postgraduate. Students can return to visual and the haptic senses; that is, what manipulations that produced a variety of bubbles time and again and delve more we see and how our bodies sense move• curved surfaces and geometric shapes. deeply into their geometry. This approach

Soap films illustrate "min• pavilion at lower right, imal principles." The designed by Chrysalis machine above enables Corp., provides shade for designers to determine Kennedy Square in De• the surface area and troit. Any shape that bub• stresses in the structure bles or soap film take can produced by inverting the be duplicated in an air- soap film (upper right). filled or tentlike structure. The soap-film-inspired

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Bubbles in a cluster follow mathemat• ical laws and take only two basic geometric configurations. Three sur• faces can meet along a line at angles of 120 degrees, or the surfaces of four bubbles (never more than four) can meet at a vertex at angles of about 109 degrees. In the 1940s, botanist E. B. Matzke discovered that bubbles in such an array have an average of 14 sides. Examples of the shapes he noted are shown above. A 14-sided polyhedron is the ideal geometric shape for en• closing space, requiring the minimum surface area and tension to enclose a given volume. Bubbles, then, provide a model for many natural and human-made phenomena in which structure follows "minimal princi• ples." Examples on the opposite page: spots on a giraffe, underside of a mushroom, cells in a dragonfly's wing, and dried mud. By playing with bubbles, children will learn that dis• covering and explaining these pat• terns is a vital part of science. (All il• lustrations from Structure in Nature Is a Strategy for Design, by Peter Pearce, M.l.T. Press)

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to learning may be quite different from nipulation just because something is conventional methods but is just as valid. beautiful and fun, seem to be left at the Teachers usually explain concepts and school door. then try to illustrate them through dem• For example, I once tried out some of onstrations or experiments. But with my ideas in a suburban school system bubble blowing, the concepts arise out of noted for its innovative and enlightened the materials—much closer to the way we programs. In one school, the principal put learn in everyday life. And all the while stu• me in a basement room more like a closet. dents are working with a beautiful and in• Not only was it out of sight, but I suppose trinsically interesting phenomenon. it was also out of smell: the odor of dish• I have yet to mention all the possibilities washing soap tends to hang around, no that stem from a soap film's interaction matter how well one washes up afterward. with light. Only by practice does a child And many of the teachers got curious develop the perceptual skills important in looks on their faces whenever I talked cognitive growth. Playing around with about my "math" class. soap film—watching how the patterns of But curiously, both teachers and par• change in subtle ways—is a ents look much more favorably on bubble pleasurable way of exercising such skills. blowing at the Children's Museum. And aside from encouraging their aesthe• Everybody is always very enthusiastic dur• tic sensibilities, children can learn about ing special programs for visiting school the phenomenon of light interference. One children. And parents usually encourage interesting experiment is to make a film in their children to get involved, often asking a closed container and let it sit for an hour how bubble blowing can be done at home. or so. The liquid will gradually evaporate, I have seen this happen with other "un• leaving a film that doesn't reflect any conventional" educational activities— light. Nothing like this can be seen outside there is a tolerance for "frivolous" activi• of a laboratory! ties when done in the "proper" context. I Underlying all these educational pos• think there is an important message here. sibilities is the poetry of bubbles, which Recent years have seen a well- can provide philosophical insight into life documented decline in student interest itself. A bubble isn't a bubble if it lasts for and abilities in science and math• a long time—part of its fascination is that ematics—and this apparently starts early you never know when it will pop. If you on. In one study, for example, nearly half try to "capture" bubbles, by taking their the third-grade students interviewed said picture or enclosing them in a bottle, you they did not want to take more science. have a different kind of experience. Some Only a fifth of the eighth graders ex• of the best moments in life are like that. A pressed a positive attitude toward science festival, a play, a concert is exciting and courses, and this percentage remained wonderful partly because it is short-lived. constant throughout high school. But the The first moments of love, an intense con• students said they liked science when they versation with a friend, the birth of a child learned about it outside school—through are there and then gone. We can't hold on museums, planetariums, "marine to them, even though many of us try. worlds," and the like. Maybe these places Blowing bubbles is a continual reminder are onto something. that we would do well to savor those fleet• Perhaps schooling and play are incom• ing experiences. patible, especially when it comes to play• ing with messy materials. If so, we ought Reforming Science Education to provide other opportunities for chil• dren to keep alive their fascination and Now, I certainly encourage everyone to wonder. After-school child-care programs blow bubbles. But my greater concern is offer such opportunities. However, I'm the education of children. Too much of not convinced that education can't be their formal education is dull and rote— more fun. The joy, as well as the learning, the learning of formulas and methods. that I've seen come from blowing bubbles Some of this is useful and necessary, but it tells me that we need to reawaken the often dominates the school day and most spirit and the energy that went into re• of the school year. Teachers often devote forming schools in the 1960s. If we en• little time to the fascinating human-made courage a basic sense of play, the work of and natural phenomena right around us. school will provide more lasting Exploration just for its own sake, and ma• rewards. •

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