Why does everything goes to equilibrium?

[Skhandelwal]

In everysingle thing in the world, everything tries to set up equilibrium, reaction b/w two objects, etc. But why? It is one of those questions that you never even think about. Like what causes charge. It is strange that now when I am taking AP classes, I have began to think about this simple concept. What causes equilibrium? I mean change always needs energy but this is one change that requires energy to stop it.

 

[pseudovector]

You got it the other way around; it's not that thing tend to go to places we declare to be equilibria, but instead, we observed where things like to go to and according to that declared them to be equilibria. Moreover, equilibria are states where the total force is zero. Hence, when something is not at an equilibrium, there will be a force to move it, so it won't stay there.

 

[radou]

...Hence, when something is not at an equilibrium, there will be a force to move it, so it won't stay there.

Something can move at constant velocity and still be in equilibrium.

 

[Integral]

An equilibrium state implies a local minimum in the energy. It requires an addition of energy to the system to move it out of the equilibrium state. Thus things tend to seek an equilibrium as energy is lost to the environment and other factors. The system will finally reach a situation where the various energy inputs equal the various energy losses creating a equilibrium situation.