Why Do Soap Bubbles Rush Toward Static Electricity—While Paper Butterflies Flee? The Shocking Science Explained!
I am Ken Kuwako, your science trainer. Every day is an experiment!
Bubbles drifting through the air usually float aimlessly, following the whims of the wind and gravity. But what do you think would happen if we introduced a certain “invisible force”? Yes, I’m talking about static electricity—that same force that makes your hair stand on end or gives you a little zap when you take off a sweater. Normally, bubbles just go with the flow, but how would they react to an electrostatic charge? Would they stand at attention like hair near a plastic ruler? Just thinking about it is exciting, so I decided to head to the lab and find out!
What You’ll Need
- A balloon
- A towel (wool or cotton works best)
- Bubble solution and a wand
How to Do It
Get your gear ready. First, rub the balloon vigorously with the towel to build up a strong static charge. 
2. Gently blow some bubbles into the air. 
3. Bring the charged balloon close to a floating bubble. 
What did you see? It’s like magic! 
The bubble is drawn toward the balloon as if pulled by an invisible string.
The Great “Push and Pull” Mystery
Let’s compare this to another experiment using static electricity: the “Static Butterfly.”
If you watch the video, you’ll see that butterflies made of tissue paper actually “run away” from the charged object. So, bubbles are attracted, while paper butterflies are repelled. They move in completely opposite directions! Why does this happen?
The Science: The Secret of Attraction
When you rub a balloon with a towel, it generates static electricity. Typically, materials like rubber or vinyl pick up electrons from cotton or wool, giving the balloon a negative (-) charge. Now, consider the bubble. It’s made of soap and water. That “water” part is the key. Water molecules (H2O) have a very specific shape. While the molecule is neutral overall, the oxygen (O) side is slightly negative (-), and the hydrogen (H) side is slightly positive (+). We call this “polarity.” As you can see in the following video, water is highly reactive to electricity.
So, what happens when the negatively charged balloon gets close? Exactly! The positive (hydrogen) sides of the water molecules are attracted to the negative charge of the balloon, causing them to swivel and face it. 
(Note: This diagram shows an example with a positive charge, but with our negative balloon, the positive side of the water molecules would be the side pulled in.)
As a result, positive charges gather on the side of the bubble closest to the balloon, and negative charges move to the far side. This phenomenon is known as electrostatic induction (or more precisely, dielectric polarization). Since the positive charges are slightly closer to the balloon than the repelling negative charges, the overall force is one of attraction. That is why a neutral bubble is pulled toward the balloon!
Then why does the butterfly run away?
It comes down to the difference between water (bubbles) and paper (butterflies). When the paper butterfly touches or gets very close to the charged object, electrons actually jump across. This gives the butterfly the same negative charge as the balloon. Just like two “North” poles of a magnet push each other away, like charges repel. That’s why the butterfly takes off! While the bubble just rearranges its molecules to stay close, the butterfly shares the charge and flees. Fascinating, isn’t it?
Taking it to the Next Level: The Van de Graaff Generator!
If you crank up the static power, the experiments get even more dramatic. I’ve posted videos of large-scale experiments using a professional static generator. These include experiments I’ve conducted on TV programs with celebrities like Suzu Hirose, Ryohei Suzuki, Yasuko, and the comedy duo Chocolate Planet. Check out the details here. 
https://phys-edu.net/wp/?p=34632 Please note: Experiments using a Van de Graaff generator must always be performed under the supervision of a professional. Stay safe while exploring! For requests regarding static electricity experiments (workshops, TV supervision, or appearances), please contact me here.
[Special Feature] Addictive! Fun with Static Electricity
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