6 min read

Demonstrating Electrostatics

Demonstrating Electrostatics
Image courtesy of WikimediaImages via Pixabay.

Prerequisites Required- None

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Be certain to read the Some Comments on Accuracy section at the end of this article to ensure that historically out of date theories presented here do not circulate in modern contexts.

Today, we set out to demonstrate one of mankind's first experiences with electricity; electrostatics. If you've ever observed your hair behaves strangely after it's been rubbed by a balloon, you've experienced electrostatics.

This demonstration requires some fur, silk, two glass rods, some string, and a stand to hold one of the rods.

Figure 1: An electrostatics demonstration can be performed with two glass rods, some fur, silk and a stand.

The fur, silk, and glass rods can be easily purchased online. The stand was laser cut from clear acrylic but could be 3D printed, made using a building set, or otherwise improvised. The stand model is available here: Rod Stand

Figure 2: Left- CAD Model of rod stand | Right- Assembled rod stand

As a control, we start by bringing the two glass rods near each other. As expected, nothing particularly interesting happens.

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Figure 3: Glass rods don't normally interact

For the first part of our demonstration, we rub both glass rods with silk.

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Figure 4: Glass rods being rubbed with silk

After rubbing them, we again bring them near each other. Surprisingly, we find that the rod in our hand repels the other rod! By following along with the rotating rod, we can actually get it to spin pretty fast.

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Figure 5: After rubbing glass rods with silk, they repel each other.

Jonathan Bowen