How is Static Electricity Produced?

Static electricity is produced when one object takes negative charges from another object. For example, amber becomes negatively charged when rubbed with wool, because amber attracts negative charges (electrons) and will take them from wool. As a result, the amber becomes "negatively charged," and the wool, due to its loss of negative charges, becomes "positively charged".

The distribution of electrical charges in amber and wool before and after rubbing is shown below:

Amber	Wool		Amber	Wool
Amber before rubbing Equal # of charges Neutrally charged	Wool before rubbing Equal # of charges Neutrally charged		Amber after rubbing More negatives than positives Negatively charged	Wool after rubbing More positives than negatives Positively charged

How can a piece of amber pick up a feather?

You can pick up a feather after rubbing amber with wool.

When a piece of amber is "charged up" it can pick up feathers and other light objects by electrostatic induction. (Don't worry, it's easier to understand than you might think.) When a negatively charged piece of amber is held above a feather, the negative charges in the amber repel the negative charges in the feather. If the feather is touching the ground or some other object, many of the feather's negative charges will move onto the other object allowing the feather to become positively charged. Then, if the attraction between the negatively charged amber and the positively charged feather is great enough, the feather will leap up onto the amber.

Electrostatic toys were popular in the 1800's

There were many wonderful electrostatic toys invented in the 1800's. To run them experimenters needed a reliable source of static electricity so they invented larger and more efficient electrostatic generators (A). With these generators they could power all kinds of fascinating electrostatic toys (B, E, F). Below the picture is a listing and brief description of each labeled item.

A) Electrostatic Generator: Produces static electricity by spinning a glass globe against a leather pad.

B) Franklin's Bells: When charged, the metal balls swing back and forth causing the bells to ring.

C) Insulating Stand: Insulates the top part of the static generator (D) from the table.

D) The Prime Conductor Stores and distributes the static electricity to the toys connected to the static generator.

E) Dancing Dolls: When charged, a figurine will fly up and down from plate to plate.

F) Electroscope: Measures the amount of static electricity stored in the prime conductor.

How do electrostatic toys work?

Electrostatic toys use the forces of attraction and repulsion to operate. To understand how these toys use these forces it is necessary to understand how charges are separated by an electrostatic generator. This picture shows where there is an overall positive and negative charge.

This device is made of three key parts: a negatively charged bell, a positively charged bell, and a hanging ball. If the ball hits a bell it will gain that bell's charge. 

For example, if the ball hits a positively charged bell it becomes positively charged. Then, because the ball and the bell are positively charged, they repel each other (Figure 5a & 5b). When the ball hits the negatively charged bell, the ball instantly becomes negatively charged and is repelled again (Figure 5c). The ball will swing back and forth changing from positive to negative until the there is not enough static electricity to move ball.

E) Dancing Dolls:

When the attraction between the negatively charged figurine and the positively charged metal plate is great enough, the figurine will leap up and touch the top metal plate (Figure 6b). As soon as the figurine touches the top plate it becomes positively charged and is repelled away (Figure 6c). When the figurine hits the bottom plate it becomes negatively charged once again and springs back up to the top plate (Figure 6d). This continues until there is not enough static electricity to overcome the weight of the doll.

F) Electroscope:

Electroscopes measure the amount of static electricity stored in an object (Figure 7a). An electroscope works because like charges repel. As an electroscope is filled with a particular charge, positive or negative, all of those like charges begin to repel. If there are enough repelling charges the ball at the end of the electroscope is repelled away from the rest of the electroscope (Figure 7b). In addition, the electroscope is calibrated so you can actually measure the amount of static electricity stored in an object.

*An interesting fact:
When your hair stands on end due to static electricity, you are an electroscope.