It's not accurate to say there are only 5 branches of physics. Physics is a vast and complex field, and there are many ways to categorize it. Here are some of the most common and fundamental branches, along with their core focuses:

1. Classical Mechanics:

* Focus: The study of the motion of objects, taking into account forces and their interactions.

* Examples: Newtonian mechanics, kinematics, dynamics, gravitation.

2. Electromagnetism:

* Focus: The study of the interaction between electric charges and magnetic fields.

* Examples: Electricity, magnetism, light, electromagnetic waves.

3. Thermodynamics:

* Focus: The study of heat and its relation to energy, work, and temperature.

* Examples: Entropy, heat transfer, statistical mechanics, thermodynamics laws.

4. Optics:

* Focus: The study of light and its behavior, including reflection, refraction, diffraction, and interference.

* Examples: Lenses, mirrors, lasers, fiber optics.

5. Quantum Mechanics:

* Focus: The study of the behavior of matter and energy at the atomic and subatomic levels.

* Examples: Quantum particles, wave-particle duality, quantum entanglement, quantum field theory.

Other Important Branches:

* Relativity: Studies gravity and its effects on spacetime, encompassing both special and general relativity.

* Nuclear Physics: Focuses on the structure and properties of atomic nuclei, including radioactivity and nuclear reactions.

* Astrophysics: Studies celestial objects and phenomena, such as stars, galaxies, and the universe.

* Condensed Matter Physics: Investigates the properties of matter in its various forms, including solids, liquids, and gases.

It's important to remember that these branches are interconnected and often overlap. Many physicists work across multiple fields, and new areas of research are constantly emerging.