Coil

Coil built on the workshop's habit of physical analogies, but hers was about momentum rather than water. "A coil is like a heavy flywheel," she'd say, spinning her paw. "A spinning wheel doesn't want to start suddenly, and once it's spinning it doesn't want to stop suddenly. A coil is the same with current — it resists sudden change. Push current in fast and it pushes back; cut it off fast and it tries to keep it going." Inductance, she explained, is that pushback-against-change, and it's measured in henries.

But the part she loved most was the reach. She'd build a simple electromagnet on the breadboard — wire wound around a nail — and touch the current on and off, and the nail picked up paperclips and dropped them. "Current in the loop makes a magnetic field," she said. "Turn the current up, the field grows. That's a motor. That's a speaker. That's the doorbell and the crane that lifts cars. All of it is current becoming magnetism in a coil."

Coil never made it mysterious. "It's a wound wire," she'd say. "You can build it — wrap wire around a nail, run current, watch it grab a paperclip. Turn the current off, watch it let go. Every bit of it is right there on the bench to see." SEE-and-BUILD, the workshop way — even for the invisible field, whose reach you could map with a scatter of iron filings or the jump of a paperclip.

Coil came from a warren of spring-makers who built the toys and traps of the village — everything that snapped, sprung, or spun. Young Coil was fascinated by the one spring that worked without touching — a wound wire that reached out invisibly. The day she made a nail pick up a paperclip across a gap of air, she understood her craft: a loop of current is a reach — invisible momentum you can aim.

One day Watt, the workshop mentor, came to the warren.

"What is a coil?" Watt asked.

Coil wound a loop in the air and waved it near a paperclip, which jumped. "It's a wound wire that turns current into a magnetic field," she said. "It resists sudden change — like a flywheel resists starting and stopping — and it reaches across a gap to pull or push. Motors, speakers, electromagnets: all coils. And you can build one with wire and a nail." Watt smiled. "You are appointed," he said.

In her classroom, Coil begins each lesson with the paperclip jump, then hands out wire and nails and lets the students build their own electromagnets and feel the invisible reach switch on and off under their fingers.

She teaches her students a few habits about coils: A coil turns current into a magnetic field. Wind wire in loops, run current, and it reaches out invisibly — pull, push, move. It resists sudden change. Like a heavy flywheel, a coil doesn't want current to start or stop abruptly. That pushback is inductance. More loops, stronger reach. Add turns of wire (or a nail core) and the field grows. You can feel it grab harder. Off doesn't mean instant. A coil tries to keep its current going for a moment when you cut it — the flywheel coasting down. * A motor is a coil that spins. Current becomes magnetism becomes motion. Every motor you own is this trick, repeated.

Coil tells her students, "My first electromagnets were too few turns and barely grabbed a thing. That's not a failure — that's a weak field asking for more loops. Add turns, try again, feel it grab harder."