The boys and I watched the first episode of Leverage the other morning. As I had anticipated, they loved it. The first episode ends with the whole team staring at the camera, while their leader explains what they do.

“The rich and powerful, they take what they want. We steal it back for you. Sometimes bad guys make the best good guys. We provide leverage”

“Leverage?” my youngest son asked. “What’s that?”

“It’s. . . um,” I floundered for a minute, then hopped to my feet. “It’s physics. I’ll show you. Get up.”

“Da-ad!”

“No, really.” I grabbed a broom, knelt down on one knee, and unscrewed the head of the broom, turning it into a five foot long stick.  “Both of you, come on. I’ll show you. This is one of the basic machines that helped build our world.”

They gave me their “we’re not that gullible” look.

“Trust me.” I placed the broomstick across my knee, and waved my oldest son over. “You hold this side,” I said gesturing to the short end of the broom. I motioned his little brother to the long end. “You hold that side.”

Cautious but curious, they moved into position. If you’re having trouble understanding what was happening, imagine an unbalanced seesaw, with my knee as the fulcrum. My older (and larger) son was holding the short end of the seesaw, and my younger son had the much longer end of the seesaw.

“Okay,” I said. “On the count of three, I want you both to push down. Let’s see who’s stronger.”

They both pushed. The broomstick held even for a moment, then my younger son’s end went down to the ground.

“So,” I said. “Who’s stronger?”

“I am!” the little guy shouted.

His big brother started to make excuses.

“It’s a lever,” I interrupted. “Pushing on the long end exerts more force, or leverage. It’s one of the ways that people move things that are way too heavy for people to move. It’s pretty safe to say that if people hadn’t discovered levers, none of this,” I gestured to the house, “could have been built.”

“Lighter weight on the longer end.” My oldest son was holding the broom, and looking at it. “That’s how we balance things!”

“Yep.” I said. “Two genius points to you.”

“Bet your knee hurts,” his little brother said.

“Yeah.”

It was a good lesson, but the next time we talk physics, I’m going to try to make sure it’s not quite so painful.