THE COMPLETE BOOK · FREE TO READ
Wires and Switches
Vince’s little lamp shines, goes dark, and shines again as he changes one connection. Compare a dry wooden bridge with foil, then see a movable metal contact become a switch for his block street.
Turn the pagesOr scroll to readA light for the street
Pages 1–2
A light for my little street. We get the parts ready.
Explore together · Preparing a battery-and-lamp circuit
Vince points to his wooden street while an adult brings the parts on a tray. The two free clips are apart and the lamp is dark. The battery supplies energy, but the lamp needs a complete conducting path through its two contacts. The prepared set leaves one gap for Vince to join.
Ask together: What do you notice about the two clips on the tray?
Joined clips, shining lamp
Pages 3–4
I join the clips. My lamp shines!
Explore together · Completing the path
The red and yellow metal jaws touch, and the small lamp shines. The wires lead from the battery through the lamp and back. With working matched parts, joining the metal contacts completes this single conducting path. Electric current itself is invisible; the light is an observable result.
Ask together: Where do the red and yellow clips meet?
A gap in another place
Pages 5–6
A gap here? Dark. Together again. Light.
Explore together · Every connection in a single path matters
Vince lifts the black return clip from the battery holder, then reconnects it. The lamp is dark, then bright, while the red and yellow clips stay joined. A break elsewhere in this same path also stops current through the lamp. Restoring that connection completes the path again.
Ask together: Which connection changes between these two pictures?
A wooden bridge
Pages 7–8
A wooden bridge... ...but no light.
Explore together · Physical contact is not enough
The clips grip opposite ends of a dry wooden stick. The metal jaws are separated, and the lamp remains dark. The stick bridges the physical gap, but this dry wood does not carry enough current to light the lamp. The rest of the circuit remains connected.
Ask together: What is between the two metal jaws now?
A foil bridge
Pages 9–10
A foil bridge... ...and it shines!
Explore together · Comparing conducting materials
A strip of foil takes the wood’s place between the separated clips, and the lamp shines. The wooden stick rests beside Duck. Clean aluminum foil provides a conducting connection here. Comparing the same apparatus helps distinguish the material change from a loose connection elsewhere.
Ask together: What changed, and what stayed the same?
Making an easier connection
Pages 11–12
These clips are fiddly. We make a little switch.
Explore together · A movable contact
Vince finds a foil clip fiddly. An adult helps with a metal arm on a card; one end stays at a pivot and the other can move toward a second contact. The arm can open or close the existing path without repeatedly joining the two loose clips. The lamp remains part of the circuit.
Ask together: Which end of the metal arm stays attached?
Hello and good night
Pages 13–14
Hello, little street! And... good night.
Explore together · Using a switch
The arm touches the second contact and the street’s lamp shines. With the arm turned away, the lamp is dark. A switch controls whether this path is complete. It does not create electricity; the battery still supplies the energy.
Ask together: What changes at the far end of the metal arm?
Remembering the little street
Pages 15–16
For grown-ups
Pages 17–18
For Grown-Ups Vince changes one small battery circuit. We can see the parts and what the lamp does. Electric current itself is invisible. A path all the way round A working lamp needs a complete conducting path through both lamp contacts and both battery connections. Opening either gap stops current in this single path. A loop drawn on paper would not be enough: the parts must connect properly. Touching is not enough Dry wood does not carry enough current to light this lamp. Clean aluminum foil can. A bridge can look complete but still contain an electrical break. A dull lamp can also mean a loose contact or weak batteries. A connection we can move The metal arm stays attached to one contact. Turn it to touch the other, and the path closes. Turn it away, and the path opens. The switch controls the path; it does not make the electricity. Energy for the light The battery supplies energy. The lamp transfers electrical energy to light and heat. Current is not a substance that gets used up inside the bulb. Explore together Use an adult-prepared, low-voltage educational battery-and-lamp set with matched parts. An adult handles cells, small parts, sharp ends and all construction. Keep the lamp in the path: never join the battery terminals directly. Never use wall sockets or mains-powered equipment. Keep everything dry. Make brief observations, disconnect afterward and let hot lamps cool. Can you follow the whole path? Where could a gap stop the light? If a test stays dark, ask the adult to check the known working connection. Sources: Science Buddies; Exploratorium Teacher Institute; Energizer Science Center; Nebraska Extension.
Open these pages in the readerSources and evidence
In the pictured low-voltage battery circuit, closing the final conductive connection through the correctly rated working lamp lets it light.
Which Materials are the Best Conductors?
Circuit Workbench — Exploratorium Teacher Institute
Use adult-prepared, low-voltage educational parts that match. Loose contacts, weak cells or a faulty lamp can keep an apparently joined circuit dark.
Opening a different point of that single path also extinguishes the lamp; the lamp needs the entire connected path.
Which Materials are the Best Conductors?
The different-gap comparison concerns the single unbranched path shown. A circuit with another available path can behave differently.
A dry plain wooden craft stick between separated clip jaws does not light this lamp, while clean aluminum foil bridging those same jaws can.
Which Materials are the Best Conductors?
Make a Simple Circuit — Energizer
Metals — They’re Electrifying! — American Chemical Society
The comparison uses dry plain wood and clean aluminum foil. Moisture, coatings and contact quality can change results; appearance alone does not establish conductivity.
A movable metal connection can serve as a switch: contact closes the path; separation opens it.
Make a Simple Circuit — Energizer
Making a Switch — University of Nebraska–Lincoln Extension
The metal arm must stay in conducting contact at its pivot and actually touch the second contact when closed. An adult prepares and checks the small parts and sharp ends.
The battery supplies energy; the lamp transfers electrical energy to light and heat, while current is not consumed as material inside the bulb.
Circuit Workbench — Exploratorium Teacher Institute
The battery supplies energy transferred by the lamp to light and heat. Electric current is invisible and is not a substance consumed by the lamp. The energy explanation is in the grown-up guide.
A story worth keeping?
Read it here as often as you like. The physical edition is coming soon.