The Smithsonian's Lemelson Center for the Study of Invention and Innovation Beanie illustration

HomeAbout SparkLabActivities and experimentsInventor profilesResources

SparkLab logo

  Activities & Experiments

lightbulb icon

Use this form to record the results of your "Make a light bulb" experiment.

  • ELECTRICAL CIRCUIT: the path of the current as it flows through a wire from an energy source (like a battery) and back to an energy source, usually from positive to negative.
  • CURRENT: the flow of electrons in a circuit.
  • FILAMENT: material that gives off light in a light bulb when heated by an electrical current passing through it.
  • SHORT CIRCUIT: the interruption of the regular flow of electricity when the circuit is shortened, often by crossing bare wires.  In household current this causes heating up of wires and often a fire.

Thomas Edison tried hundreds of times to make filaments that would glow and not burn up.  He used many different materials, from cardboard to bamboo.  Edison was persistent--he never gave up trying until his project worked!

The electric light bulb works because you have made a complete circuit with electrical current flowing out from the battery, through the filament and back to the battery.  The electricity flowing through the wire produces heat and makes the filament glow.

Test number

Number of strands
of iron wire

Number of seconds filament lit Burn or glow