Rocket pushes a stick into the padlock. Nothing turns.
"Why not? It fits in the hole!" Rocket says.
Raven slides in the real key. Click! It turns.
"What do you notice? Same hole, different shape," Raven says.
Nova glows a row of tiny rods inside.
"Would you like a hint? Watch how high each rod goes."
Inside the lock body is a row of slots.
Each slot holds a tiny pin.
A second pin sits on top of it.
A small spring pushes each pair down.
The pins block the lock, so it cannot turn.
The key slides under the pins.
Each bump pushes one pin up.
The right key pushes every pin to the right spot.
Then the lock can turn. Click!
A wrong key pushes the pins to the wrong spots.
So the lock stays shut.
| Sentence | True or false? |
|---|---|
| Springs push the pins down. | ? |
| A wrong key pushes the pins to the right spots. | ? |
| The right key lets the lock turn. | ? |
| The pins block the lock when no key is in. | ? |
Tall bumps lift pins high. Short bumps lift them a little.
Each lock needs its own pattern of heights.
The key's shape is made for one job: fit this lock.
You found the secret of the bumps. Clever!
Tomorrow we look very closely at a real padlock.