
At the deepest level, everything in the universe is governed by a small set of fundamental interactions.
From the motion of planets to the structure of atoms, from nuclear reactions in stars to the chemistry of life, all physical phenomena arise from just four fundamental forces.
In theoretical physics, understanding these interactions is the key to understanding reality itself.
In this guide, we’ll explore:
- The four fundamental interactions
- How they differ in strength and range
- How modern physics describes them
- The search for a unified theory









