system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Bubbles are spheres. If I blow on the bubble it deforms, then it reforms into a sphere. Does the reforming need energy to happen or is surface tension "built in energy"?

Meaning that the energy used to create the bubble helped form the surface tension. And deforming it uses more energy than reforming it.
gpt
A sphere is the state with the least potential energy (why, because geometry and because electromagnetic forces are exerted equally in all directions). When you deform it, you add the energy in the form of electromagnetic energy between the molecules (polar molecules) in the bubbles (think of it like pulling two magnets away from each other which have a north and a south pole closest to each other). The magnets then closer to each other because this is the state with the least energy. You pulled the magnets apart.