Bubble bubble bubble best ball in the world. The bubble is made for boys and girls. Blowing Bubbles when I was a kid was so fun blowing them from a bottle container. Now they have bubbles blowing from a toy gun. This is what you see my daughter have in the picture above.  Bubbles are visible because they have a different refractive index (RI) than the surrounding substance. For example, the RI of air is approximately 1.0003...