Extreme Science: Penny Shine

What you will need:

  • 1”x3”x9” block of wood (approximate size)
  • Solid wire such as an old metal coat hanger
  • Electronic buzzer and/or small (flashlight) bulb with holder (both can be purchased at Radio Shack
  • D cell battery
  • Battery holder (Radio Shack)
  • Thin (flexible) electrical wiring. Probably easiest to but some wiring that has alligator clips at both ends (approximately 24” long)
  • Various “crimp on” style electrical connectors
  • Crimping tool. Pliers can be used if necessary.
  • Adult supervision


  1. Mount the battery holder and buzzer/light holder along one side of your piece of wood as shown:

  2. Connect a wire from one end of the battery holder to the bulb holder (if applicable), then from the other end of the bulb holder to the buzzer. If you are not using a bulb, connect this wire from the battery holder directly to the buzzer. Insert bulb if applicable.

  3. Take a stiff wire (approximately 20” in length) and bend it into a nice curvy shape. Make sure to make a small loop at the end that will be mounted to your board so that you can insert a screw through the loop to connect the wire to the board. Mount this wire and connect the other wire from your buzzer to this wire as shown:

  4. Using another stiff wire that is approximately 6-8” long, bend a loop that is about ¾” – 1” in diameter at one end to make your wand. Attach a wire to the opposite and connect the other end of that wire to your battery holder as shown. Insert battery in holder.

  5. Touch the wand to the large wire that is mounted to the board. This should complete the electrical circuit causing the light to light up and the buzzer to buzz. If everything works as it should, try feeding the loop of your wand over the bent wire carefully guiding it all the way on trying NOT to make contact. The object of the game is to get the loop all the way on and then back off as quickly as you can without touching the wire, thus causing the light to light up or the buzzer to buzz.

What is going on?

Electricity will flow through conductive materials such as metal. Since there are wires that are connecting the the light, the buzzer and the bent wire together at one end of the battery and your wand at the other end of the battery, as soon as you touch the wand to the bent wire, you are completing the circuit and allowing the electricity, or current, to flow through the light and the buzzer by creating a return path. When your wand is NOT in contact with the bent wire, the circuit is open, meaning that the electricity cannot flow completely through the circuit and will not activate the buzzer or the light. This is basically just like the light switch on your wall. When your light is on, the circuit is closed (allowing the current to flow through the light bulb and back to ground) and when the light is off, the circuit is open and the current does not have a return path to ground.

Try this:

You can time yourself and see how quickly you can get the wand all the way on and back off without touching and try to improve your time each time you attempt it. You can also have contests with your friends to see who can do it the fastest without completing the circuit.

NOTE: Make sure that you do not leave this game where the wires may remain in contact with each other as the battery may overheat.

Radical Rick

Extreme Science