All of us at one point or the other in our childhood have blown bubbles and chased them as well. Bubbles are the fragile transparent balls floating through the air with rainbow colors peeking through them.  Playing with bubbles is the favorite among children of the world irrespective of the race, nationality and all..

However what’s the science behind (or inside) a bubble?  How bubbles are formed and is there any Science behind the simple act of bubble making? Bubbles actually provide the opportunity to study science concepts such as

elasticity,

surface tension,

chemistry,

light, and

even geometry.

Wow so many concepts in such an ordinary play thing…Isn’t it great? Would you like to explore more??? So lets go..

We can start by making the soap solution and then by making a wire loop and waving it in the air we find that a bubble is created or take a straw and dip it in soap water and blow.. Lo and behold there is a bubble coming out from the end which was dipped in the soap water.. Well all this is fine but how are the bubbles formed? If you look at the bubbles these are nothing but the soap films with air trapped inside it. Soap film is made from soap and water (or other liquid). The outside and inside surfaces of a bubble consist of soap molecules. A thin layer of water lies between the two layers of soap molecules, sort of like a water sandwich with soap molecules for bread. They work together to hold air inside.

Now the next question arises as to why the bubble is round in shape?

Well the soap film can actually take any shape. However the moment you set the bubble free it takes the spherical shape for the simple reason that the surface area of the sphere is the smallest for a given volume.. So the moment the bubble is let loose the tension in the bubble skin shrinks to the smallest possible shape for the volume of air it contains. That’s why even if it had a funny shape before it was let loose, once adrift in the air, the bubble will shrink into a sphere shape.

Why do bubbles pop?

Other than being poked or landing on something sharp, bubbles pop when the water between the soap film surfaces evaporates. To note, when it’s cold, those molecules take longer to leave. If you blow a bubble on a calm winter day, a bubble can even freeze and last for several minutes before it pops. Also, the colder the outside temperature is, the higher a bubble might fly. That’s because the warm air from your breath is lighter than cold air.

What about the rainbow that we see on the bubble and sometimes our face too.. How does that happen?

A bubble gets its color from light waves reflecting between the soap film’s outer and inner surfaces. The distance between the layers gets smaller as the water evaporates, making the colors change. Bubbles can also reflect what’s around them, like the faces peering at them.

Why do bubbles stick together?

The answer to this question lies in the shape of the bubble and the surface area that it occupies. Since a bubble tends to minimize its surface area, bubbles will join together to share one common wall. Three bubbles will meet at the center, always at an angle of 120 degrees. Isn’t this fantastic.. Why not blow some bubbles on a paper and then verify this ??

HOW TO PERFORM THE EXPERIMENT:

Dishwashing soap ( 1 cup)

Water 4 cups

Glycerin 4 TSP

Take a straw and you are ready..

To do this experiment you need a clean smooth surface.

Wet it with water .

Dip your straw in bubble solution and blow from the other end you will see the bubble forming.. Go near the surface the bubble will attach itself to the surface..

Dip the straw again the soap water and try to make a bubble inside the first one..

See how many you can make (one inside the other)

Now dip your finger  in the soap solution and poke the bubble.. You will find that you can pass through the bubble without popping it.. Try it with different things like scissors, needle, pencil etc.. You will find that you can pass through it without any problem.. Now touch the bubble with the dry finger.. The bubble pops.. Why?..when your finger is dry the water molecules trapped inside the soap film is attracted to the dry surface ( your finger in this case) causing the bubble to pop..