In this activity, students investigate the fascinating geometric patterns created by bubbles. They’ll observe that bubbles always meet in groups of three and form equal angles—patterns that also appear in honeycombs and other natural structures.
Materials
Clear glass or plastic cup
Milk (any kind)
Drinking straw
(Optional: cookies or round crackers for a hands-on analogy)
Procedure
1. Make a Bubble Column
Pour the cup about halfway full of milk.
Place the straw into the milk.
Blow gently to create a tall layer of bubbles.
Stop and look closely at how the bubbles connect.
2. Observe the Connections
Guide students to notice:
✔ Bubbles join in groups of THREE
Look for any point where bubble walls meet—you should always see three bubble “walls” coming together, never four.
✔ They meet at EQUAL angles
Use a protractor if you want to measure:
Each of the three angles where bubbles meet is about 120°.
This happens no matter the size of the bubbles.
Why Does This Happen?
1. Why a single bubble is round
A bubble forms when gas is trapped inside a thin liquid film.
Pressure pushes outward.
Surface tension pulls inward.
The smallest, most efficient shape for holding air is a sphere.
2. Why bubble groups change shape
When two bubbles touch, the combined system rearranges to use the least possible surface area. That’s why:
Two bubbles share a flat wall.
Three bubbles join at 120° angles—this is the most efficient arrangement.
Four bubbles at a single point would require more surface area, so nature avoids it.
3. A Simple Analogy
Place several cookies or round crackers on a table:
Put one in the center, then fit the others around it.
Every junction involves three cookies, just like three bubbles.
Imagine the cookies becoming soft enough to blend together—the angles between them would naturally approach 120°.
This mirrors how bubbles arrange themselves.
Real-World Connections
This efficient geometric pattern appears in many places:
Honeycombs
Bees build hexagonal cells because:
Hexagons pack tightly
They use the least amount of wax
Their angles are all close to 120°
Foams & Biological Tissues
Cell structures in plants and foams often show the same “meet in threes” pattern.
Engineering
Soap films and bubble clusters help scientists study:
Minimal surfaces
Structural efficiency
Packaging and packing problems
Cleanup & Extension
Students can:
Sketch the bubble patterns
Measure angles with protractors
Compare bubble geometry to honeycomb photos
Try the same activity with soapy water to compare bubble sizes
Optional: Let students model bubble connections using cookies, play dough, or round counters.
