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Foam bubble blower

By David Shaw, 2 September 2021

That’s a lot of bubbles!

Bubble blowers come in all kinds of shapes and sizes. This one blows thousands of tiny bubbles that you can play with. It makes a foam that lasts, so you can even shape the bubbles into towers!

Safety: Ask an adult to help, as this activity uses a scalpel or box cutter. Use clean hands and equipment, as the bubble blower will touch your mouth. Create a bubble blower for each person that wants to blow bubbles, so that you don’t share germs.

You will need

• 600 mL plastic bottle
• Scalpel or box cutter
• Cutting board
• Sports sock
• Rubber band (optional)
• Bubble mix (you can use premade bubble mix, or use our recipe)
• Bowl
• Towel

What to do

1. Get an adult to carefully cut the bottom off the bottle, by using the scalpel or box cutter on a cutting board.
2. Ask the adult to check the edge of the bottle to make sure there aren’t any sharp edges.
3. Carefully pull the sock over the bottom of the bottle.
4. Keep going until the bottle is tucked into the sock, and the toe is stretched tightly over the cut end.
5. If needed, secure the sock in place with a rubber band.
6. Pour the bubble mix into the bowl.
7. Put the bottle into the bowl, sock-end down. Wait for a few seconds for the bubble mix to soak in.
8. Pull the bottle out again and let the excess bubble mix drip back into the bowl.
9. Take a deep breath, then put the mouth of the bottle to your lips and blow steadily. Bubble foam will appear out of the sock!
10. You can keep blowing into the bottle to make more foam. Just remember to breathe in away from the bottle – you don’t want to inhale bubbles!
11. Once you have plenty of foam you can make bubble towers or sculptures.
12. When you’re done, remember to wipe up the bubble foam with a towel. It can get very slippery!

What’s happening?

That’s a lot of bubbles! But how does it work?

A regular bubble wand has one hole. When you dip the wand, a film of bubble mix covers the hole, and when you blow through the hole, the film bows outwards. Eventually, the film bends so far that it closes behind itself and forms a bubble.

This foam blower is similar, only with more holes. If you look closely at your sock, you’ll see that it’s made of threads, all looped together. And in between the threads, there are tiny gaps, which act as tiny bubble wands!

Our foam lasted for many minutes or even hours – much longer than a single bubble. There’s a good reason why this foam sticks around for so long.

If left untouched, individual bubbles usually pop because the bubble mix flows down to the bottom of the bubble, and the top ends up too thin. Inside a foam, the top of one bubble is the bottom of another. As bubble mix flows down, more comes from above to replace it. The bubbles on top of the foam pop, but inside they are more stable. And there are a lot of layers of bubbles to pop before the whole foam goes away!

More information

If you want to learn more about popping bubbles, check out how scientists found shock waves travelling though bursting bubbles.

If you’re after more science activities for kids, subscribe to Double Helix magazine!