It was bound to happen; then one day it did. I was shuffling along the Infinite Corridor toward Barker Library with a heavy load of overdue books when a freshman suddenly ran up to me. “I know you!” she shouted, her finger pointed directly at my face. My mind raced. Warily, I looked at her for signs of what this encounter was about. “You’re Mr. Magnet! You came to my school when I was a little kid. You chose me to push the button to launch Garfield on the Boomer! It was the most fun I ever had at school,” she said. “Are you still doing Mr. Magnet?”

“Yes, I …” I was speechless.

She turned to run off to class. “Bye, Mr. Magnet! Keep doing what you’re doing!” she shouted. Giddiness washed over me as memories of 17 years of school visits came flooding back.

The MIT Plasma Science and Fusion Center has long welcomed school groups for lab tours and lectures. To enrich their experience, I would engage young visitors in demonstrations of magnetic phenomena. In 1992, a teacher accompanying her students asked if I would bring my magnetic bag of tricks to the Fowler Middle School in Maynard, MA. So I loaded a few cardboard boxes stuffed with wire, batteries, and assorted magnets into a van and set off with a grad-student assistant.

The response from the kids and teachers was so positive–and MIT was so supportive of the project–that I soon found myself trundling off to as many as three or four schools every week, encouraging kids to do hands-on experiments like deflecting glowing plasmas with a dipole magnet or heating and cooling a nugget of gadolinium to change its magnetic property. Over the years, I went through three trucks, into which I packed almost three tons of equipment–including rolling tables, a sound system, the six-foot, million-volt Van de Graaff generator known as the Lightning Machine, and the adaptation of Doc Edgerton’s sonar apparatus we call the Boomer.

After logging 150,000 miles on more than 1,100 school visits, I can recall countless memorable moments. The kindergarten boy who broke the electromagnet’s power button by pushing it too energetically. The scores of times children told me they wanted to be a scientist like Mr. Magnet. The day we hit the launch button on the Boomer to demonstrate how a pancake-shaped electromagnet could catapult Garfield across the school gym and watched as his flight path ended in the ceiling light fixture. But above all, I can recall every detail of the warm spring day I met Mikey.

I had finished my show at an elementary school and was bringing my equipment out of the gym to load into the truck. The school bell announced recess; children poured from several doors and fanned out onto the muddy playground, which was tinged with tender sprouts of green in the wake of winter’s receding glaciers. The children carelessly discarded coats, hats, and mittens, their screams and shouts announcing their joy to be outside.

Another voice, small and thin, caught my ear; I turned to see a frail young boy with twisted hands and a bright smile, flailing his arms from his wheelchair to get my attention. I drew near. “What’s your name?” I asked.

His reply was a breathy squeak. I looked up at his attendant, who answered for him. “He can’t talk, really. His name is Mikey. He would be thrilled to hear the horn on your big truck.”

I thought for a moment, then asked, “Could we put Mikey up in the driver’s seat and let him blow the horn himself?”

“Oh, that would be wonderful! It would make his day,” she replied.

I lifted Mikey and sat him behind the wheel. While his attendant held him steady, I placed his hands on the horn button and told him to press hard. Nothing happened. My heart sank; he didn’t have the strength.

“Mikey, you can do it! Press as hard as you can,” I urged him. He pushed at the button and squirmed, and finally the horn sounded. The children on the playground were silenced; soccer balls dribbled away and stopped; birds took flight from their perches; and Mikey waved his hands and squealed with delight. He had made the horn sound himself, and the world heard it.

Paul Thomas, a technical supervisor at MIT’s Plasma Science and Fusion Center, has reached almost half a million students through his Mr. Magnet shows and millions more through television appearances.