Dressed in a lab coat, a man going by the name of "Hazmat Bond" lined the boys of Cub Scout Pack 688 up against the gym wall at Shipley's Choice Elementary School to face the firing squad.
He raised something that looked like a leaf blower and took aim. As the amped-up boys awaited their fate, parents stood watching from the sidelines.
Class was in session.
The leaf blower was loaded with pingpong balls and Hazmat Bond was Matt Simms, an instructor with Mr. Bond and the Science Guys, a raucous, roving workshop that provides children lessons in everything from density (by using bouncing rubber balls) and pressure (a makeshift potato detonator) to gyroscopic torque (a jury-rigged "vortex cannon").
This evening with the Cub Scouts was among the instructional group's first local appearances since the company, based in Nashville, Tenn., expanded in Maryland as part of a growing movement to package the teaching of science with rocketry, explosions and chemical reactions — in other words, fun.
"There are a lot of companies popping up. Science is really hot right now," said Chantal Bertrand, spokeswoman for Mad Science in Canada, which holds similar workshops around the world. "When kids are engaged and they're mesmerized by something, their curiosity is heightened and they learn better."
Most teens enjoy science but are bored by textbook teaching, according to a June survey by the Amgen Foundation in California, which works to advance science instruction, and Change the Equation in Washington, D.C., which promotes science, technology, engineering and mathematics (STEM) education. The online survey of nearly 1,600 teenage students found 81 percent said science was interesting, but only 37 percent said they enjoyed their classes a lot. These teens ranked hands-on experiments as the most engaging teaching method.
Enter Mr. Bond and the Science Guys, amateur but enthusiastic itinerant "scientists" intent on transforming science from "ho-hum" to "oh, wow!" in the minds of young people. They're following in the much larger footsteps of the Mad Science Group, which has 3,000 instructors and 165 franchises around the world, including in China and Saudi Arabia.
Mad Science instructors launch backyard rockets, demonstrate with dry ice and create indoor lightning storms at school assemblies and birthday parties. The Canadian company's closest franchise is in Washington, D.C., but instructors sometimes travel to Baltimore.
They'll now have some competition with Mr. Bond and the Science Guys' recent foray into Maryland.
"The whole focus is making science fun," said Simms, 32, a musician turned instructor.
Mr. Bond and the Science Guys workshops have been offered for nearly two decades in Nashville, where Simms trained under founder Keith Trehy. Trehy taught a science class at the University of Strasbourg in France before moving to Tennessee and becoming Mr. Bond.
Six years ago, Simms was playing guitar for former "American Idol" contender Haeley Vaughn, and was a session guitarist who opened for bands like Alabama Shakes, the Fray and Florida Georgia Line. He studied music at Colorado State University, graduated in 2007, then moved to Nashville to pursue a career in rock 'n' roll.
"The road life is not what it's cut out to be," Simms said.
He met Trehy at a coffee shop in Nashville. The company was hiring; Simms figured "Why not?"
Soon he was touring libraries, schools and birthday parties as science guy "Hazmat Bond".
"The joy of working with kids is so much more than my guitar riff," he said.
He followed his girlfriend Siena Trehy, who is Keith Trehy's daughter, to Baltimore. Siena Trehy, a senior at Goucher College, had offered occasional workshops on her own, but now she and Simms plan to branch out and offer the workshops as a couple throughout Maryland.
Keith Trehy holds about 2,000 workshops a year in Nashville, reaching about 20,000 children.
"We decided to fully franchise and bring everything we offer in Nashville to Baltimore," Siena Trehy said.
They offer an hourlong show with bubbling potions, explosions and chemical reactions. A birthday party costs about $250.
On the recent evening, Simms entertained 40 Cub Scouts at the elementary school in Millersville.
He handed a bouncy ball to scout Upton Young and challenged the boy to reach the ceiling. The 11-year-old bounced the ball off the floor; it pinged off the rafters.
Next, Simms challenged pack leader Darren Vican, who stands 6 feet, 10 inches tall and weighs 240 pounds.
"He might have given him a different ball," whispered Amy Blank, a mother of one scout.
Vican threw the ball and it barely bounced to his knee.
"Aw!" the boys shouted.
Simms slipped in a lesson about density. One rubber ball, he explained, was denser, with less space to compress and bounce.
"I'm afraid we might be doing this at the house," Blank said.
Her 8-year-old son, John, has made volcanoes at home and inspected bugs under his microscope.
"He's into rocks now," his mother said, and his collection is carefully arranged in egg cartons.
John rushed up.
"This is crazy!" he said. "Balls being shot at us! detonators getting hit!"
Nearly an hour had passed by the time Simms began the final lesson: velocity.
He revealed the pingpong-ball launcher. The boys could barely contain themselves.
"Quiet, quiet," Simms said.
He directed them against the wall and aimed — it was too much; the scouts shouted, laughed and jumped in anticipation.