What did Aymeric Roux and colleagues discover about soap bubbles?

• A. They can last for a year or more.
• B. Bubbles can pop immediately in any air.
• C. They require special lighting to be seen.
• D. They are unaffected by ambient temperature.

Answer: (B)

The key idea here is how fragile a soap-bubble film is and how quickly it can rupture when disturbed by the surrounding air. A soap bubble is a film only a few hundred nanometers thick, held together by surfactants that lower surface tension. This film is constantly thinning as gravity, evaporation, and air flow drain liquid away. When the film becomes critically thin, tiny disturbances—air currents, dust particles, or even slight vibrations—can create a tiny hole. That hole can rapidly propagate across the film, causing the bubble to burst in an instant. In everyday air, such disturbances are common, so a bubble can pop immediately rather than lingering for a long time. This is the essence of what Roux and colleagues observed: bursting can happen essentially right away in ordinary air conditions.