MAKE BUBBLE ART  more experiments

As seen on Channel 8's Let's Talk Live!

Materials:

1/4 cup washable liquid Tempera paint

1 T. water

1 T. dish soap

bowl or cup

spoon

straw

paper

Directions: 

Create a solution by stirring together the first three ingredients in the bowl or cup.  Using a straw (and being careful not to suck in), blow out into the paint solution until a mound of bubbles forms.  Gently place the paper on top of the bubbles until they flatten out.  Repeat until you have a design you like!  Try different colors, or blowing large and small bubbles to change the texture.

Science:

Bubbles don't form well in water alone because the surface tension of water is too great.  Soap helps to reduce the surface tension of water and allow bubbles to form and hold their shape more easily. 

Soap also slows down the rate at which the walls of the bubbles evaporate. Bubbles usually pop because the water in them evaporates.  Glycerin and other thickening agents have water-holding properties that delay evaporation, making the bubbles last longer.  When you blow bubbles on a rainy day, they last longer because there is more moisture in the air.  (What do you think happens on a sunny day?  How about a windy day?)

Bubbles are "minimal surface structures" (as are balloons). This means that they always hold the gas inside of them with the least possible surface area – and the shape with the least surface area for any given volume is always a sphere.  This is why bubbles are always round, even when you blow them through a square wand.

We see colors in a bubble through the reflection and the refraction of light waves off the inner and outer surfaces of the bubble wall.   You can't color the bubble itself since its wall is only a few millionths of an inch thick.  Instead, a bubble reflects color from its surroundings.  The thicker the bubble’s walls, the more intense the color.