Symmetry breaking

[Ostronomos]

Symmetry breaking often appears in phase transitions, where a system moves from a high temperature phase to an ordered low temperature phase.

The early universe was characteristically known to be in a high temperature phase. As its entropy continues to increase, it settles into a less symmetric state. Energy, a well-known characteristic of our universe, remains constant throughout the universe.

A ball or pencil balanced on its tip, will undergo symmetry breaking when an imbalance in forces are applied to it. This is also an increase in entropy or disorder, the measure of which is a property of every physical system as the arrow of time increases.

[confused2]

The Initial SymmetryWhen perfectly balanced on its tip, the pencil has rotational symmetry around its vertical axis.Every horizontal direction outward from the tip is completely equivalent.The laws of physics acting on the pencil treat all radial directions equally.
How the Symmetry Breaks
The upright state is an unstable equilibrium.
An infinitesimal disturbance (like a tiny air current, a microscopic surface imperfection, or thermal/molecular vibration) triggers the fall.
By choosing a single unique direction, the system destroys its original rotational symmetry. The final fallen state only points one way, reducing the symmetry of the outcome.

If you like I can explain how this relates to the Higgs mechanism in particle physics [that's Gemini NOT me]
..or discuss the mathematical role of an order parameter in this setup [Gemini again]