# Why most of the things in this universe wants to become Sphere? [duplicate]

in our solar system , every planets revolve in elliptical path and their shapes is almost oval or approaches to Sphere .

Sun is also looks like Sphere .

Question: Why everything trying to approaches Circle or Sphere?

My teachers says that even gravitational field, electric feild are somewhere looks like they are traveling in form of Sphere and he tell me that Everything things in this universe wants to Loose their potential energy that why they form Sphere

Then my next question comes in my mind that Why Spheres shapes tries to maintain Low potential energy?

Can anyone please enlighten me about why such things are happening as said in above two questions.

## 1 Answer

Fundamental forces (electromagnetic, gravitational, weak, and strong) are central forces, meaning they attract or repel along straight lines, from particle center to particle center. A dynamic system controlled by fundamental forces will reach equilibrium (a local energy minimum, if you prefer to think in terms of energy) when the net force on all particles is zero. For attractive forces like gravity, this happens when all particles in the system are packed as close to the center of gravity as possible, resulting in a spherical shape. A tacit assumption here is that the forces are equal regardless of orientation (invariant); if forces "preferred" a particular direction, meaning they were stronger when oriented in a particular way in absolute space (a concept which doesn't really exist, but for sake of argument) then the result would be maybe an ellipsoid, or a more organic shape. But of course, in our physical world, so far as we can tell, forces work the same in all directions (invariant under rotation) and the only smooth 3D shape which satisfies such a condition is the sphere.