The four major domains of physics are:
- Classical Mechanics
- Relativistic Mechanics
- Quantum Mechanics
- Quantum Field Theory
Classical Mechanics occurs at what we call “normal” speeds and scales in relation to our everyday experience. Relativistic Mechanics occurs at “normal” and large sizes, but at high speeds. Quantum Mechanics occurs at small sizes, but slow speeds. Quantum Field Theory occurs at small sizes at high speeds.
To see a World in a Grain of Sand,
And a Heaven in a Wild Flower,
Hold Infinity in the palm of your hand,
And Eternity in an hour.
– William Blake