Static Shock Science: Make a Volcano Erupt with Electricity!

This is Ken Kuwako, the Science Trainer. Every day is an experiment.

A Volcanic Eruption Caused by Static Electricity?! Let’s Use Science to Create a Miracle!

“ZAP!” That little shock you get from a doorknob on a dry winter day is something we’ve all felt. For many, “static electricity” might just seem like a pesky little prankster. But what if I told you that tiny spark holds a secret… a powerful energy just waiting to be unleashed?

It might sound unbelievable, but it’s true! Today, we’re going to use a device called a “Van de Graaff generator” to create a massive amount of static electricity. With it, we’ll perform a dynamic experiment: making countless styrofoam beads fly into the air, just like a volcanic eruption. Once you witness the incredible “repulsive force” of static electricity, your perception of it will be turned upside down!

Here are the “magma” materials for our eruption: styrofoam beads.

We’ll place these beads into a plastic cup with a hole in the bottom and fix it to the top of the Van de Graaff generator. There! We’ve recreated the scene of magma accumulating at the peak of a volcano.

Now, it’s time to switch the Van de Graaff generator ON! As the motor hums quietly, an invisible energy begins to build in the “crater”… You’ll have to watch the video to see the explosive conclusion!

When you flip the switch…

KABOOM! A massive eruption!

The styrofoam beads fly vigorously into the air, as if they’re alive!

Why Does It Erupt? The “Crowded Train” of Negative Charges

The key to this mysterious phenomenon lies in the true nature of static electricity: “electrons (-)”. A Van de Graaff generator is a machine that gathers a huge amount of negative charge (electrons) onto its metal sphere. When we place the styrofoam on it, that negative charge quickly transfers over.

So, what happens next? Every single styrofoam bead becomes coated in the same negative charge. There’s a fundamental rule in electricity: “like charges repel each other.” The styrofoam beads, now overcrowded with negative charges, are all pushing each other away, screaming, “Get away from me!” When that repulsive force hits its peak, they all launch into the air at once. This is the secret behind our “static eruption.” The way they spread out in a radial pattern is a stunning visualization of the electric field lines created by the repelling charges!

Attraction and Repulsion?! The Fickle Nature of Electricity

So, what happens if you hold some styrofoam beads in your hand and bring them close to the operating Van de Graaff generator? This time, they get pulled in, as if by a magnet!

It’s strange, isn’t it? First they repel, and now they attract. But if you watch closely, you’ll see some beads that stick to the sphere suddenly get launched away again. What on earth is going on? This is caused by a phenomenon called “electrostatic induction.”

The massive negative charge (-) on the Van de Graaff generator repels the negative charges (-) inside the approaching styrofoam, pushing them to the far side.
As a result, the side of the styrofoam closer to the generator becomes temporarily positive (+).
Electricity has another rule: “opposite charges attract.” The negative (-) generator and the positive (+) side of the styrofoam pull towards each other, causing them to stick together.
However, the moment they touch, a flood of negative charges (-) flows from the generator into the styrofoam, making it negative overall.
Now that they are “like charges” again, they repel, and the styrofoam bead is launched away.

Attraction, then repulsion. It’s like watching the fickle, push-and-pull nature of electricity in action. The fascination never ends!

The Van de Graaff Generator: A Treasure Chest of Science!

There are many other fun experiments you can do with a Van de Graaff generator. Some of these experiments were even featured on a TV show with famous celebrities like Suzu Hirose and Ryohei Suzuki. Click here for more details.

※ Please note: Experiments using a Van de Graaff generator should always be conducted under the supervision of a professional. Please be careful. For inquiries regarding science workshops, TV show consultations, or other appearances, please contact us here.

【Special Feature】You Won’t Be Able to Stop! Static Electricity Experiments

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