“Bubbles, Sharon?! I’m the f*^%ing Prince of Darkness!” With those incredulous words, spoken to his wife in an episode of The Osbournes, Ozzy Osbourne gave the only acceptable argument against blowing bubbles. As for everyone isn’t part of Beelzebub’s extended family, you either enjoy blowing bubbles, or you’re a liar.
In fact, perhaps the only bad thing about bubbles is their impermanence. Wouldn’t it be rad if there was some way to make those ephemeral orbs last a little longer? With this Demo Science science demo, your students can experiment with ways to delay the bursting of their bubbles.
Authentic Small-Batch Artisanal Craft Bubble Solution
For this one, you’ll need five plastic cups (Solos work well), a bottle of liquid dish soap, some water, corn syrup, glycerin (can probably find it at your local drugstore), sugar, lemon juice, some measuring spoons and cups, a stopwatch, a marker, and one bubble wand per student.
Start by labeling four of your cups with the additives you’ll be, um, adding to each: corn syrup, glycerin, sugar, and lemon juice. As the control, the fifth cup can be unlabeled, or you can write “soap” on it to reiterate that it’s just soap in that one.
Pour precisely one cup of water into each cup, then add about three tablespoons of dish soap to each and stir ‘em up a bit. Let your students know that the additives are the independent variable here—which one will make the bubbles last longest?—and that you’ll be comparing and contrasting the results you get from each. (Write that down, Kevin.)
Add precisely three teaspoons of the appropriate additive to each of your labeled cups and mix the solutions again. Either man the stopwatch yourself, or pass it off to your most reliable student; the stopwatcher will be timing how long bubbles last before they burst, as well as recording the results. Have the rest of your students debate which additive will yield the best results, then divide them into five groups, one for each cup.
Starting with the control solution (“soap”), have one kid dip in his/her bubble wand and blow the mightiest bubble they can. Your stopwatcher should start the timer as soon as the bubble breaks free of the wand, and stop it as soon as the bubble pops, then record the time and bubble solution used. Rotate through the groups, one kid at a time, until each student has had at last one bubble lifespan recorded. (Bubbles that hit something and burst, rather than just floating around and popping on their own, should not be counted in the results; have those students reblow a new bubble until the desired result is achieved.)
When all bubbles have been blown, have your students figure out the average time the bubbles of each different solution lasted. What are their findings?
And The Best Bubbles Be…?
Chances are better than good that the glycerin bubbles lasted the longest, since most commercially-available bubble solutions are made from water, detergent, and glycerin. This thick, clear, odorless substance is a byproduct of most soap-making processes, and, in this case, forms a bond with the hydrogen in the water to help delay evaporation (which is what causes untouched bubbles to burst).
However, science being the fickle beast that it is, it’s entirely possible that your experiment may yield different results. If so, ask your students what they think helped the winning formula outlast the glycerin bubbles. They’ll all be wrong, probably, but you’ve got to start somewhere.