In this activity students learn about minimal surface structures by trying to blow bubbles in many shapes.

If you play with bubbles and soap films, you’ll notice they come in predictable shapes. When floating around in the air, a bubble will become a sphere; and when in a flat bubble wand, a soap film is always flat, no matter the shape of the wand.

Bubble shapes are simple and predictable because deforming a bubble takes energy. Bubbles tend to spring back to the shape that is stretched as little as possible. That shape is called the minimal surface. That is why a free-floating bubble is a sphere—a sphere has the least surface area for a given volume of air. Another way to think about this is that a bubble is stretched most evenly as a sphere (as compared to an egg shape, or a cube).

### Objectives

• Make a bubble and understand its structure.

### Key Questions

• What shape of bubble do you think will come out of each shape of bubble wand?
• Why are bubbles always spherical?
• What has more surface area (what would take more soap film to create) a cube or a sphere?
• What are minimal surface structures?Is there any way to make a different shaped bubble?

### What To Do

Activity

1. ​Create a few 2-D bubble wands by twisting a pipe cleaner into a shape other than a circle (e.g. square, triangle, heart, star, butterfly etc.)
2. Experiment with the different wand shapes to create bubbles. Do the bubbles match the shape of the pipe cleaner wand? What is happening? Why do you think the wands all create the same bubble shape?

### Extensions

• Try making square and other shaped bubbles in the activity.
• Examine commercially made wands, hypothesize and test reasoning for design.

### Other Resources

Exploratorium | Bubbles

Survivors

Artist: Jeff Kulak

Jeff is a senior graphic designer at Science World. His illustration work has been published in the Walrus, The National Post, Reader’s Digest and Chickadee Magazine. He loves to make music, ride bikes, and spend time in the forest.

Egg BB

Artist: Jeff Kulak

Jeff is a senior graphic designer at Science World. His illustration work has been published in the Walrus, The National Post, Reader’s Digest and Chickadee Magazine. He loves to make music, ride bikes, and spend time in the forest.

Comet Crisp

Artist: Jeff Kulak

Jeff is a senior graphic designer at Science World. His illustration work has been published in the Walrus, The National Post, Reader’s Digest and Chickadee Magazine. He loves to make music, ride bikes, and spend time in the forest.

T-Rex and Baby

Artist: Michelle Yong

Michelle is a designer with a focus on creating joyful digital experiences! She enjoys exploring the potential forms that an idea can express itself in and helping then take shape.

Buddy the T-Rex

Artist: Michelle Yong

Michelle is a designer with a focus on creating joyful digital experiences! She enjoys exploring the potential forms that an idea can express itself in and helping then take shape.

Geodessy

Artist: Michelle Yong

Michelle is a designer with a focus on creating joyful digital experiences! She enjoys exploring the potential forms that an idea can express itself in and helping then take shape.

Science Buddies

Artist: Ty Dale

From Canada, Ty was born in Vancouver, British Columbia in 1993. From his chaotic workspace he draws in several different illustrative styles with thick outlines, bold colours and quirky-child like drawings. Ty distils the world around him into its basic geometry, prompting us to look at the mundane in a different way.

Western Dinosaur

Artist: Ty Dale

From Canada, Ty was born in Vancouver, British Columbia in 1993. From his chaotic workspace he draws in several different illustrative styles with thick outlines, bold colours and quirky-child like drawings. Ty distils the world around him into its basic geometry, prompting us to look at the mundane in a different way.