KEVIN B. KLAUS/Arizona Daily Wildcat High school teacher Erik Herman demonstrates the nature of sound waves with fire Wednesday night in the Physics and Atmospheric Sciences building. Herman's microphone carried his voice to the flame tube, which reflected his speech in visible waves of fire.

UA professors and grad students dazzled a crowd of more than 300 with fire, lasers, and bottle rockets Wednesday during the 21st annual Physics Phun Nite, and they will do it again tonight.

The Physics and Atmospheric Sciences building auditorium was filled mostly with families and elementary school-aged children during the event, which featured more than 15 acts and culminated with a professor lying on a bed of nails.

Anne Murdaugh, physics graduate student, was caped and masked to play "the Physics Defender." She used a potato gun to shoot a suspended teddy bear during a skit and made metal rings fly with a superconductor machine.

Murdaugh said she was happy to be a part of the event for a second year because it shows children the exciting parts of physics.

"It brings physics down from a bunch of equations in a book," she said. "And who doesn't love exploding things?"

Erik Herman, a Tucson High School physics teacher, drew the largest applause with his demonstration. He ignited a 15-foot propane-filled steel tube and fluctuated the intensity of the flames by singing into a microphone connected to the apparatus.

The grand finale came with mathematics professor Bruce Bayly lying on a bed of nails while Herman hammered a brick on top of him.

"The physics really does work," Bayly said. "The nails are close enough together that they absorb the force from the hammer and the brick. It doesn't hurt."

In order to make physics demonstrations available to all elementary schools in the community, Bayly recently purchased an old school bus and transformed it into the "Physics Bus." Bayly and Herman travel in the bus to bring science demonstrations to schools.

Herman said he believes events like Physics Phun Nite are important because they expose children to things they might not often see.

"In the real world, you get a job and you don't get to see this kind of stuff," he said. "Its important to do things like this to immerse them as much as you can."

Theresa Embry, physics graduate student and Physics Phun Nite host, said the event is targeted towards children to get them interested in science at an early age.

"Tops and gyroscopes got me as a kid," Embry said. "I was so interested in how those things worked."

Bayly says his upbringing contributed to his interest in science.

"I had scientists in my family and it was always around," he said. "And I was alive when they put a man on the moon."

Larry Hoffman, physics department laboratory coordinator and Physics Phun Nite event planner, remembers what prompted his lifelong interest in science.

"The professor on 'Gilligan's Island' is what did it for me," he said.

Embry said the event became so popular in recent years that the show now runs for two nights to accommodate the large audiences. A second Physics Phun Nite will be held tonight from 7 to 8:30 in the Physics and Atmospheric Sciences building.