Science in action: here's one instance in which good ideas were flushed down the toilet - again and again.

Here's one instance in which good ideas were flushed down the toilet--again and again and again.

Should we get into the toilet thing?" Beth asks.

"Sure," Tom answers "Let's get in the toilet."

Wait a minute--what's going on here? This conversation ic typical chat among the creators of Big Science Ideas: Systems, ar interactive CD-ROM made by the Minnesota Educational Computing Corporation (MECC).

CD-ROMs, short for compact disk-read only memory, are computer disks that store information, like software programs, in a digital format. Digital means that the information--words, pictures, music--is imprinted on the disk in binary code, or a sequence of 1's and 0's. A laser in the computer reads these long strings of 1's and 0's and translates them back into print, graphics or sound.

Producing a CD-ROM involves more than imprinting disks with information, however. A wide range of people, from writers to graphic artists to computer programmers, have to work together to determine what goes into the disk.

System is the key word. In fact, Big Science Ideas: Systems is all about systems. A system is a group of components that interact with each other. The MECC team that created the CD-ROM set out to explain how systems work in the three major branches of science: physical science (like physics and chemistry) life science like biology and anatomy), and earth science (like geology and meteorology).

"Just about anything can be described as a system," from the human body's circulation system to toilet, says Beth Daniels, project director of Big Science Ideas. The team at MECC wanted a system at students could relate to. The toilet seemed a perfect example.

"It's a simple mechanical system that is easily understood," says Daniels. "It continues to be an integral part of everyone's life. It's something we see every day."

The CD-ROM uses simulations, or computerized models, to explain how toilets work. For instance, students adjust the settings of the components inside the toilet tank by manipulating controls that appear on-screen. Then they can give the toilet a flush to see--well--what goes down.

Say you conduct a simulation in which you keep the goat ball at a low height, use a short flapper chain, and close the water valve in such a way that the flush lasts for 45 seconds. After entering the information using a control panel on the computer screen (see below) you click on (what else?) FLUSH to run a simulation.

Uh-oh! In this simulation, the toilet flushes but your tank doesn't refill. Read your "on-screen" feedback and adjust the controls to devise a better system.

To make the CD-ROM, planners like Daniels had to consult with teachers, students and, of course, the neighborhood plumber. Big Science Ideas: Systems created similar simulations for earth science (the system of Earth's shifting surface) and life science (the system of a common pond).

To create the pond simulation, computer programmer Ethy Cannon collected samples from a real pond near MECC's headquarters in Minneapolis, Minnesota. She poured the samples into an aquarium in her home, where she and her colleagues studied this ecosystem (the interaction of living and nonliving things that make up a stable environment). Then they used their research to devise a program that mimics what happens in a real pond.

When students go to the "cyberpond" on Big Science Ideas: Systems, they can add or subtract plants and animals with a click of the mouse. The goal of the exercise is to keep the pond in ecological balance.

Students, of course, were an important part of the creative process that brought Big Science Ideas: Systems to life. "Kids thought worksheets were boring, tests were boring, big stupid words were boring," Daniels says of chats with students who helped shape the CD-ROM. "They like to get in there and get dirty. They wanted to do something real."