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Memoirs of a Bubble Blower Memoirs of a Bubble 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 pattern: 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 surfaces meeting at a vertex at tuition in science and mathematics. 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 surface physics, cellular biology, topol• to be scientifically significant. ogy, and architecture. Bubbles and soap 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 Patterns 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 area 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. Soap film 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, color. 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 areas 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. 2 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 sphere, hemisphere, pentagon, and hexa• such things as the minimal surface 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 s EDUCATION A SPECIAL REPORT 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.
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