Amazing Inventors and Their Inventions
Every invention below solved a specific problem: darkness, distance, or the question of whether a person could leave the ground at all.
Who Were Inventors?
Inventors are people who come up with new ideas and build things that have never been made before. They are curious, and they like solving problems.
Meet the Inventors
- Thomas Edison: He invented the light bulb. Before it, nights were dark; the light bulb made it possible to have light in homes and streets.
- Marie Curie: She was a scientist who discovered radioactive elements like polonium and radium. Her work helped us understand the world of atoms.
- The Wright Brothers: These brothers invented the airplane. They made the first successful flight, and people have been able to travel the world by air ever since.
- Alexander Graham Bell: He invented the telephone. Before it, people had to write letters to reach someone far away. The telephone let them talk instantly instead.
Build a Simple Circuit
Here is how to make a simple circuit that lights up a small LED.
Estimated time: 15-20 minutes. Difficulty: easy.
- A small LED (Light Emitting Diode)
- A 3V button cell battery
- Two small pieces of conductive tape, such as copper foil tape
- Scissors
- Cut two small pieces of conductive tape.
- Look at your LED. One leg is longer than the other. The longer leg is positive (+) and the shorter leg is negative (−).
- Place the LED on the battery so one leg touches each flat side.
- Tape the longer leg to the positive (+) side of the battery with one piece of tape.
- Tape the shorter leg to the negative (−) side with the other piece.
- It should light. If it doesn't, turn the LED the other way round and try again.
Why This Works
A circuit is a path for electricity to flow. The battery provides the electricity. The conductive tape acts like a wire, connecting the battery to the LED. When the circuit is complete, the electricity flows through the LED, and it lights up.
If it doesn't light up
Almost every time, it is one of these three, so work down the list.
- The LED is the wrong way round. An LED only works one way. Turn it over.
- A leg is not touching the battery. Press it flat.
- The tape is not gripping. Make sure it is pressed onto both the metal of the battery and the metal of the leg, not onto the plastic.
Lift one piece of tape off the battery and the LED goes dark at once — the electricity has nowhere left to flow. That is the circuit doing exactly what it is built to do.