system
Given the following post, respond as if you're commenting on Reddit:
human
Why are bubbles always spherical when blown?

Whenever bubbles are blown, they appear to always be in a spherical shape of different sizes. Why not cubes or other shapes?
gpt
There are primarily two forces to consider: pressure and surface tension. There is an outward force due to the difference in pressure between the inside and outside of the bubble, and there is an inward force due to surface tension.

The force due to the pressure gradient is trying to increase the volume but the force of surface tension is trying to decrease the surface area. These forces reach equilibrium at the shape which minimizes the surface area for a given volume: the sphere.