Here's a breakdown of why:

* Focus on the Physical World: Physics deals with observable, measurable phenomena in the physical world. It examines things like motion, forces, heat, light, sound, electricity, magnetism, and the structure of matter.

* Empirical Evidence: Physics relies heavily on experimentation and observation to test and refine its theories. It uses the scientific method to gather data, analyze results, and draw conclusions about the physical world.

* Mathematical Framework: Physics uses mathematics as a powerful tool to express and predict the relationships between physical quantities. Mathematical models and equations are essential for describing and explaining physical phenomena.

* Fundamental Principles: Physics seeks to uncover the fundamental laws and principles that govern the universe. These principles are universal and apply to all physical systems, from the smallest atoms to the largest galaxies.

In contrast to other sciences like biology or chemistry, physics focuses on the most basic building blocks of the universe and the fundamental forces that interact with them. This focus on the underlying principles of the physical world makes it the foundation for other physical sciences.