What is a bubble bubble?

What causes a bubble to be formed?

• I was giving my child a bubble bath the other day, and wondered What exactly causes a bubble to form? I mean, we all know what a bubble is. And if we add soap to water, we usually can get bubbles to form. But what is the actual 'formula' for making a bubble?

• Answer:

  bub·ble (bbl) n. 1. A thin, usually spherical or hemispherical film of liquid filled with air or gas: a soap bubble. 2. A globular body of air or gas formed within a liquid: air bubbles rising to the surface. 3. A pocket formed in a solid by air or gas that is trapped, as during cooling or hardening. 4. a. The act or process of forming bubbles. b. A sound made by or as if by the forming and bursting of bubbles. 5. Something insubstantial, groundless, or ephemeral, especially: a. A fantastic or impracticable idea or belief; an illusion: didn't want to burst the new volunteers' bubble. b. A speculative scheme that comes to nothing: lost money in the real estate bubble. 6. Something light or effervescent: "Maconthough terribly distressedhad to fight down a bubble of laughter" (Anne Tyler). 7. A usually transparent glass or plastic dome. 8. A protective, often isolating envelope or cover: "The Secret Service will talk of tightening protection, but no President wants to live in a bubble" (Anthony Lewis). v. bub·bled, bub·bling, bub·bles v.intr. 1. To form or give off bubbles. 2. To move or flow with a gurgling sound: a brook bubbling along its course. 3. To rise to or as if to the surface; emerge: "Since then, the revolution has bubbled up again in many forms" (Jonathan Schell). 4. To display irrepressible activity or emotion: bubbling over with excitement.