Wonder Wednesdays – Bursting Bubbles

Why are bubbles round?

Image Credit: Pixabay

Answer: A sphere has the smallest amount of surface area of all the shapes. The surface tension makes the thin film of soap water that is the bubble try to get as small as it can be. Therefore – if I understand this correctly – if you see free falling water drops such as rain, the water drops are round as well. (The oblong shape is caused by the decent to the Earth – if it wasn’t for that, it would be round.) But because a person exhaled and trapped air inside the enclosed sphere of soapy water, the bubble can’t become a drop because the air inside pushes against the film of soap and water.

The pushing of the air and the pulling of the soapy water are equal and opposite reactions, so you end up with…

A bubble.

When blowing a bubble, the film gets thinner and thinner as it tries to wrap around the air being forced inside, and if one keeps going, one will find the point when the amount of soap required to wrap around the air pocket has run out and then…

Pop goes the bubble.

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