Tavilla recalls one time, however, when he was forced on stage. The glass in a resonance experiment, he says, just wouldn't break, like it was supposed to. A fuse was blown and he had to readjust the instruments, in front of the 500 person class.

"It's nervewracking to act in front of all those students," Travilla says. "I like it better behind the scenes."

Tavilla adds, however, that "Even though we're behind the scenes, students realize we're back there. They see us running around before class."

Being behind the scenes is also rewarding because he gets to work with Rueckner, Tavilla says.

"He's great to work with." A good boss, "he knows when to step in and when to let me tackle a challenge alone," Tavilla says.

Even better, the atmosphere amongst the team is one of humor and plenty of jokes, Tavilla adds. Science jokes, most likely.

Bigger is Better

While many scientific demonstrations can be bought pre-packaged, because most of the packages are designed for classrooms of 20 to 30 people, compared to the close to 500 that the Science Center lecture halls hold, Rueckner and his staff build 95 percent of the experiments themselves.

"We like to make them BIG," says Rueckner, adding, "A degree of showmanship makes [the demonstrations] memorable."

For the most advanced classes, demonstrations become more difficult. "There is much you can't drag into the hall for show and tell. But, those [most advanced] courses aren't taught in the Science Center, so it doesn't matter," he says.

When increasing size is not feasible, Rueckner sometimes spices the experiments up in other ways. For the shattering wine glass demonstration of resonance, the motion is slowed down with a stoboscope. The team can also use video cameras. In either case, says Rueckner, grinning, "It's really impressive how much glass can flex."

Education First

Though they are fun, Rueckner explains that lecture demonstrations "really help the education process."

"Of hundreds of lectures I've seen, the ones that had demonstrations are the ones that I remember," he says. "The principles from the others I have forgotten."

"Harvard is unique in its emphasis and appreciation of lecture demonstration," adds Rueckner. And he lights up and smiles when he notes that, over his tenure in the Harvard demonstrations arena, the program has "really evolved into a much larger and more complex organization."