Please Do Touch : Hands-on exhibits encourage experimentation--but it looks and feels like playing.

Try explaining soil erosion to a kid and it usually winds up like this: “As water moves across the Earth, it exerts forces that can be very slight, yet compounded over many yearsitcanhave-agreateffectonhowz-z-z-z-z-z-z-z. . . .”

At the Discovery Science Center in Santa Ana, they’ll teach kids about soil erosion, but they won’t say a word.

Instead, they will let the kids discover the Stream Table--shallow troughs of water flowing as if down a gentle hillside.

No matter how little you are, one of the troughs will be within reach, and it’s OK to stick your hands in. You can build hills, dams, lagoons, rivers and creeks. You can see the water carve a riverbed. You can put in a rock and see the water part and eddy. You can have fun.

This is science education?

Yes, and it works, says Mark Walhimer, the center’s vice president for exhibits.

“The purpose is to excite kids about science. The atmosphere is open-ended, informal--not a school atmosphere, purposely not.

“At exhibits like the Stream Table, the kids seem to be playing, but it’s really experimentation. It’s ‘I do this and look what happens!’ ”

There will be about 100 exhibits in the Discovery Science Center when it opens Saturday. And all, whether aimed at toddlers or adults, will have this hands-on element of play, Walhimer said. “Play is part of exploration, and it’s ingrained in kids. You just tell them it’s OK to do it.”

This approach was pioneered at San Francisco’s Exploratorium, which opened in 1969. Before then, science museum demonstrations were behind glass. You pushed a button to start them, then watched.

At the Exploratorium, the exhibits were open and required visitors to manipulate them. Such exhibits “motivate children and adults to become more inquisitive,” the Exploratorium’s acting director, Robert J. Semper, wrote in 1990. “They encourage the development or redevelopment of curiosity.”

Something Deeper Than Simply Learning a Specific Fact

After visiting science museums, people say that “they begin to notice things in the outside world that they have missed before,” Semper wrote. “Clearly, something basic has happened, something deeper than the mere learning of a specific fact or idea.”

What happens, said Janet Yamaguchi, the Discovery Science Center’s education director, is the hands-on exhibits create “an excitement and an awareness that science is all around you.” Your science receptors are turned on, and now science principles are important and make sense.

To reinforce the effect, the Discovery Science Center has planned its exhibits around its slogan, “Science--Southern California Style.” Where possible, exhibits will relate to something in Southern California living, Yamaguchi said.

“If you go to the Exploratorium, it’s a big, dark building. It’s very much what they wanted, a community effort in a building important to the community [the Palace of Fine Art, built in 1915].

“But for us in Southern California, we have a much more colorful building, with a cleanness and crispness and lots of light.”

Many exhibits will be tailored to Southern California experiences, Yamaguchi said. The video wall will demonstrate the science behind popular Southern California activities--mountain biking, rock climbing, surfing and beach volleyball. The Shake Shack will simulate the feel of earthquakes. One area is devoted to manned flight in recognition of the region’s ties to the aerospace industry.

Such hands-on experiences are needed in schools, but Yamaguchi noted that many teachers lack “the academic background to teach science the way it should be taught.”

Background information and exhibits at the center can help, but Yamaguchi noted that the public schools can’t really afford them. “In Orange County in particular, if teachers want anything extra, they have to buy it out of their own pockets,” she said.

So the science center staff has been developing field-trip and teacher-training programs over the last 5 1/2 years to help educators improve science instruction from kindergarten up.

At the Launch Pad, the center’s exhibition hall at Crystal Court shopping mall in Costa Mesa, more than 20,000 students passed through on field trips last school year. Already more than 15,000 are booked for field trips to the new center, Yamaguchi said.

Teachers Are Asked: ‘What Area Do You Need Help In?’

During the last school year, nearly 600 teachers came to the science center staff for coaching in science instruction. “In some cases it was how to do science fair projects and how to conduct a science fair,” Yamaguchi said. “Other times it was forensic sciences or earthquakes. We just ask them: ‘What area do you need help in?’ ”

The new center will include a room full of personal computers, and teachers will be given instruction there when the museum is closed Mondays.

“These last few years have allowed us to work with school districts to develop something they need,” Yamaguchi said. “The districts don’t have the resources to be able to train their teachers for everything.”

Instead, she said, “we have positioned ourselves as an educational resource at least as important as any library.”