Young Scientists
Bulb Brawl
Wire a row of bulbs so they shine — then we YANK one out. Bulbs sharing a wire (series) glow dim and ALL die when one breaks; bulbs on their own branches (parallel) stay bright and survive a failure — but cost more wire. It is exactly why one dead holiday-light kills the strand but your bedroom lamp doesn't darken the kitchen. Solo vs four wiring bots + live whole-class rooms where every circuit lights up and the teacher pulls a bulb.
For Educators
Built for the classroom
Series vs parallel circuits and Kirchhoff's conservation, through play — re-implementing the lesson of PhET's Circuit Construction Kit. Each round gives N bulbs and a wire budget; students wire them into parallel lanes (each lane a series chain). In series the bulbs SHARE the battery's voltage (k in a lane each glow at ~1/k², and one break opens the loop so all die); in parallel each bulb gets the FULL voltage (bright) on its own path, so a failure is isolated — but every lane costs more wire. The headline at the reveal is the YANK: pull one bulb and the series strings black out while the parallel ones hold. The deep idea, in the gated theorem: current is conserved at every junction and voltage divides around a loop — which is why your house (and every room's lights) is wired in parallel and old holiday strings (series) failed one-kills-all. Our test (14 green) proves the brightness law (1/k²), total light Σ1/k, and the yank invariant (series survival 0, parallel N−1, survival = N − largest lane).
Grades 3+ · 5–7 bulbs with a wire budget that won't cover all-parallel (so the choice is real) · solo is a best-of-5 Workbench vs four bots — beat ⚡ The Sage for the License · live rooms light every circuit then the teacher presses YANK.
Three ways to play
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Play solo
Five rounds vs four wiring bots: 🔌 Sparky → 🪫 Drainer (one series lane — one yank kills it all) → 🔗 Splitter → ⚡ The Sage (max parallel). Be best in 3+ rounds to earn the License and unseal the Theorem.
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Host a Room
Everyone wires the same bulbs secretly; at the reveal all circuits light up on the projector, then you press YANK — the room watches series strings die and parallel ones survive.
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Join on any device
Choose how many parallel lanes; watch brightness, wire, and survival update. Bright AND fault-tolerant wins.
Run a live class in 5 steps
- Open the Room — share the 4-letter code / QR / link.
- Students join on any device; everyone gets the same bulbs + wire budget.
- Each kid wires the bulbs into parallel lanes (secret until the reveal).
- At the reveal every circuit lights up — then press YANK and watch which survive.
- Reveal the rule (series shares voltage & dies together; parallel is bright & robust) only after they've seen it — then the Dojo's Circuit Lab + theorem.
Tip: host on a laptop or projector (the big screen shows the code, QR and leaderboard); students join on their phones or laptops.
