remember that a "soap bubble" is basically a very thin film of soap water that forms a hollow sphere, and exhibits iridescent surface. Soap bubbles usually last only a few seconds and then explode by themselves or by contact with another object.
The bubble is a thin layer of water trapped between two layers of surfactant molecules, often soap. These "surfactants" have hydrophilic heads and hydrophobic tails. The hydrophilic heads are attracted to the thin layer of water and maintain intact pump
The bubbles in the background and physical termios are a type of "container" gas and gas law says that "all gas pressure is constant and equal anywhere inside the body that contains it," ie, pressure is equal at any point within the container, what happens is that this contenerdor is not "solid" is flexible and dynamic is normally comes even balance between the force that the gas (air) that is exerted on the inner walls bubble by trying to expand and outside the bubble kept closed.
So why is spherical?
that the force of contraction of the bubble is the same everywhere on the inner wall of the bubble, and the expansion of the air force is also the same in any part of the inner wall, both are dynamic,
So if you have a body which exerts a thrust force equal in all directions and one that contains fuerxza of contraction exerting the same in all web addresses ... the only way that can meet those conditions is the sphere, (Vector) talking.