The sturdy wooden roller-coaster and marble-launcher look more like toys than teaching aids, but they are now standard equipment in the science classrooms of the Cambridge public schools. And manufacturer Cambridge Physics Outlet, started by five MIT graduate students, is hoping to see them used by students nationwide.
The marble-carrying Rollercoaster and Marble Launcher are just two components of a modular system designed by five current and former MIT graduate students-Thomas Hsu (now CPO president), John Urbahn and Christian Kurz of nuclear engineering, and Adam Brailove and Darren Garnier of physics. They decided to create devices to teach physics to children in grades 6-12 because all five had had teaching experience and were dismayed at the equipment and textbooks they encountered.
"Somewhere along the line, we completely destroy kids' enthusiasm for learning math and science," said Dr. Hsu, remarking on studies showing that science goes from being a favorite subject of fourth-graders to one of the most disliked a few years later. "If you want to improve math and science literacy, you can't wait until kids get to high school because you've already blown it." The CPO equipment is intended to promote enjoyment of physics as well as rigorous teaching. "We want to teach real sciences, i.e., making measurements and looking for patterns in nature," he explained.
At the heart of CPO's design is an electronic "photogate timer" that can be clamped to any of several pieces of equipment. With it, students can measure intervals of movement by a wooden car traveling along a sloped track, or of marbles which are falling, rolling or shooting upward, all to within 0.0001 seconds. By experimenting with the marble Rollercoaster, for example, they can calculate and predict velocities and thus derive the law of conservation of energy-"but I never tell the kids that; they tell me that," Dr. Hsu said. (One group even learned the effects of friction when they unsuccessfully tried a marble-rolling experiment after sending a sugar-coated doughnut hole down the track).
The rest of the equipment is a durable and simple-looking combination of ordinary phone wire, birch plywood, rubber strips, ball bearings and adjustable knobs. The interchangeable pieces also include pendulums, pulleys and wooden gears. "They look like toys, but they start as CAD [computer-aided drawing] designs. It's a very high-tech process," said CPO vice president Audra Hamilton.
"The fact that they look like toys is not an accident;" the experiments were designed to be fun for students to use and also easy to build, noted Rick Dery, director of sales. In fact, the equipment is available as kits or plans for construction by vocational-technical students, a feature that promotes collaboration between different groups. "We have AP kids taking carpentry," said Dr. Hsu, who taught that subject as well as physics at Cambridge Rindge and Latin School and at the Cambridge School in Weston.
Dr. Hsu, who is also a visiting scientist at the Plasma Fusion Center, recently began working at CPO full-time, where he still does curriculum development and teacher training. That work is reflected in the teaching guides that come with the equipment. Each experiment has three different guides which vary in detail and sophistication, so a classroom with students of different aptitudes can work on the same labs simultaneously. Julieann Villa, a junior in chemistry, helped write the guides while working at CPO as an MIT Public Service Center Fellow (see accompanying story).
The company, which has three full-time employees, moved from Dr. Hsu's basement to warehouse space in Woburn last June. So far this year, CPO's sales have totaled more than a third of the figure for all of 1994. The company is now displaying its wares at national trade shows and teacher conventions, and the city of Boston is using the experiments in a pilot program. New products in the pipeline include an atom-building game to teach chemistry and a tensile tester to illustrate engineering principles.
A version of this article appeared in MIT Tech Talk on March 15, 1995.