What is needed

• Liquids: water, dish soap, and glycerin (you can buy this at a drugstore or at the grocery store.)
• Things to blow bubbles with.
• Somewhere you don't mind having bubble solution get on the floor. This stuff is really slippery!

What to Do

• You can make as much bubble solution as you want by mixing it in the following proportions:

  2 parts water

  +

  1 part dish soap (Dawn brand seems to work well)

  +

  1 part glycerin

   

Mix it all up in a clean container, and let it sit for a while.

 

(This recipe was worked out by David Sites, a junior high school student who works with us in the Little Shop of Physics. Thanks David! Exactly how much of the different liquids you use is not too crucial, but this particular mix seems to work very well.)

 

• Now you are ready to test your bubble solution. Dip something that you can use to blow bubbles into the bubble solution. You can use all sorts of things - a funnel works really well (dip the small end) as does a piece of chicken wire or coarse screen (lots of holes means lots of bubbles!) or a straw. Here is Amy Brobst blowing bubbles with some coarse screen (called "hardware cloth") that we got at the hardware store:
  • 

    (Photo from the "Everyday Science" television program.)

• Try some other things with the bubbles:
  • If you get your hands wet with the bubble solution, you can hold the bubbles in your hands!
  • If you wet the end of a straw with bubble solution, you can insert it into the inside of a bubble without breaking it! Then you can blow into the other end of the straw to inflate the bubble, or you can blow another bubble inside the first one!
  • Get a bubble to rest on a table or on the end of your finger. Now watch the reflection of a bright light in the bubble. Check out the swirling colors!

What is Happening

You can blow pretty good bubbles with any dish soap if you dilute it with some water. But adding glycerin makes the bubbles last longer - and makes the colors brighter! It seems to make the solution a bit thicker, which makes for thicker, beefier bubbles.

The colors in the bubbles come from interference between light that reflects from the inside of the bubbles and the outside of the bubbles - some of the light will cancel, which gets rid of some colors - but leaves other colors. If you want to know more about how this works, come to Colorado State University and take a physics course with us!

Other Things to Try

We have been blowing bubbles with other gases recently. If you blow bubbles with helium, they will float very nicely. How about if you blow them with a blow dryer? Will the resulting "hot air bubbles" float?