What's the biggest magnet on Earth?

Give up? The Earth itself.What's the best shape to use in architecture for support purposes? The triangle.

What's an acceptable pH level for Emigration Creek? 8.5. What bad things are dogs capable of swallowing? Oh, super balls, needles . . .

Three hundred junior high school girls learned all this and more at the annual "Expanding Your Horizons" math and science conference at Westminster College Saturday. Girls only! The 18-year-old conference is intended to encourage girls to go into scientific and technical fields, in which women have been historically under-represented.

But most of the girls at the conference weren't worried about all that - they were just having a good time. Pleasant Grove High School sophomore Jorgia West-brook spent one workshop testing Emigration Creek for acidity, oxygen (eight milligrams per liter), carbon dioxide (20 milligrams per liter) and other things.

"We looked at little bugs and stuff," she said.

Other girls built their own World Wide Web pages, operated on pigs' feet, created models of their own "spaces of solitude" with clay and learned how to palpate an animal (OK, a teddy bear) to identify what foreign objects the animal may have swallowed.

The whole idea, in fact, was to show girls that you can actually have a good time doing science.

While they were enjoying themselves, however, "If you're not careful you might actually learn something," said Jayceen Nicholson, a Hansen Planetarium employee who was one of the conference's two keynote speakers (the other was UCLA physics professor Margaret Kivelson).

Nicholson did her part to bring lofty concepts down to earth. She played tug of war with an electromagnet, built up an electric charge in one "victim, er, volunteer" making her hair stand on end and showed how static electricity works by shuffling around on the carpet.

"You're picking up electrons from the floor and they go all over your body," she said. "Ooh, gross."

"It's been a lot of fun," Westbrook said.