The term “physical” comes from the Greek word physis which translates “reality” or “nature”, so that we can affirm that it is the science that analyzes the relationships of space, time, matter, energy and the relationships between them.
It is one of the so-called “hard sciences” or “exact sciences”, since it deals with the study of reality by applying the steps of the scientific method, which demands rigorous observation, experimental verification and other methods that guarantee accuracy in its hypotheses and results.
Physics finds its natural language in math, whose tools it borrows in order to express the relationships it deals with. In addition, it has frequent meeting points with chemistry, biology and other disciplines such as engineering and geochemistry.
pillars of physics
Physics is based on four basic theoretical “pillars”, that is to say, in four large areas of interest from which the different phenomena of the subject are approached. They should not be confused with the branches of physics, which are its structure as a scientific discipline.
- classical mechanics. The study of the laws that govern the movement of macroscopic bodies that move at speeds much less than the speed of light.
- classical electrodynamics. The study of phenomena involving electromagnetic charges and fields.
- Thermodynamics. The study of mechanical phenomena involving heat.
- Quantum mechanics. The study of fundamental nature at small spatial scales.
Branches of physics
Physics can be classified into three types:
- classical physics. It is concerned with studying phenomena whose speed is small compared to the speed of light, but whose spatial scales exceed the perspective of atoms and molecules.
- Modern physics. He is interested in phenomena that occur at speeds close to the speed of light, or whose spatial scales are of the order of atoms and molecules. This branch developed at the beginning of the 20th century.
- contemporary physics. The most recent branch deals with non-linear phenomena and processes outside of thermodynamic equilibrium.
Within this classification, we can organize physics into branches according to the size of the objects they study, as follows:
- Cosmology. It is interested in the relationships existing in the totality of the universe, as a uniform and joint entity. This implies understanding the origin of everything that exists, managing hypotheses about where the universe is going and what its future may be.
- Astrophysics. His interest lies in the relationships between stars. It is the study of physics applied to astronomy. It studies the origin and evolution of stars, galaxies, black holes, and all physical phenomena that occur in outer space.
- Geophysics. Limiting their perspective to planet Earth, geophysicists deal with the relationships of the matter that makes it up, from its magnetic field to the fluid mechanics in its molten metal core.
- Biophysics. Devoted to the study of life, physicists in this branch are interested in the relationships of the matter that makes up, surrounds and houses living beings, which may involve the study of their bodies, their cells or their ecosystems.
- atomic physics. His study focuses on the atoms that make up matter and the interactions that exist between them.
- Nuclear physics. This branch deals essentially with atomic nuclei, their components, and what happens to them during, for example, nuclear fission and fusion processes, or radioactive decay. Nuclear physics is studied within the framework of quantum mechanics.
- photonics. This branch of physics, which is also part of quantum mechanics, is interested in photons, which are the elementary particles associated with the electromagnetic field. In the frequency spectrum of visible light, photons are what is commonly known as light.