3 ms·

Why the earth is a sphere.

• OkayPhysicist 6y ago
  Systems tend towards low-energy states (because small perturbations keep things from getting stuck at local minima or saddle points. The lowest potential energy configuration for a bunch of particles pulled together by gravity is a sphere, because every point is as close to to the middle as possible.
  • Caylio 6y ago
    That decreases potential energy, but doesn't all that extreme pressure heavily increase the thermal or kinetic energy towards the center? So while this configuration decreases the potential energy, doesn't it also increase the thermal/kinetic energy? Is it obvious that the decrease of potential energy "wins" over the increase in thermal/kinetic?