What is physics?
The words "physics" is of Greek origin, literally translated as "nature." Today it is one of the most ancient sciences of the natural science cycle, mention of which is found in the ancient Greek scientist Aristotle (6th century BC.). What is physics? Today, under it understand the science of the general laws of nature, matter, its movement and structure. The classical laws of physics are considered the basis of all modern natural science.
Subject of science
Physics can be called the science of nature in the most general sense of the word. It studies matter or matter, energy, general types of interaction of the forces of nature. Physics is considered to be a fundamental science, since other natural science disciplines study only classes of material systems that obey physical laws. Physics is closely related to mathematics, since all physical laws are described using the methods of the mathematical apparatus. In addition, the development of some areas of mathematics has occurred solely due to the achievements of physicists. So, there is a whole section - mathematical physics.
History of physics
The formation of modern physics has gone through many stages, each of which contributed something new to physical knowledge, modernized fundamental physical concepts.
The foundations of modern physics originated in the 5-6th centuries. BC er It is believed that the term "physics" was first published in his writings by the ancient Greek philosopher Aristotle. Other Greek philosophers Euclid and Ptolemy created the foundations of mechanics, optics and other branches of modern physics. Great contribution was made by Indian scientists. Thus, the astronomer Ariabhata proposed elliptic models of planetary systems, and the thinkers of Dignaga and Dharmakirti laid the foundations of elementary particle physics.
In the middle of the XVI century in Europe began a scientific revolution in connection with the invention of scientific research methods. Thus, over the next 100 years, scientists have developed and proved the foundations of all modern fundamental physics. This period of time begins with the work of Nicolaus Copernicus, and ends with a whole galaxy of talented researchers: G. Galileo, I. Kepler, B. Pascal and, of course, I. Newton, who created the basic laws of mechanics.
At the end of the 19th and the beginning of the 20th centuries, all classical physics was turned upside down by the research of A. Einstein, E. Rutherford, and N. Bohr. They changed the mechanical paradigm in physics, inventing the theory of relativity and the theory of the atom.
Today, physics is mostly engaged in the study of fundamental laws. In addition, the emphasis shifted to the development of nuclear physics due to the discovery of radioactivity by substances by Henri Becquerel. The creation of quantum physics gave an impetus to the active development of microelectronics and solid-state physics, without which the existence of entire branches of modern industry does not seem to exist.
Directions of physics as a science
The main branches of physics as a science are the following areas: theoretical, applied and experimental physics.
The main task of theoretical physics is the formulation and clarification of the basic laws and phenomena of nature. In addition, theorists are directly studying what physics is, laying the foundations for practical research.
This section is considered basic for natural science, because it is with the help of experiments that they prove or disprove laws and theories, they are looking for experimental data. Theoretical and experimental physics complement and reinforce each other. By the way, many discoveries in physics appeared in the experiment, and not by theoretical analysis.
Since its inception, physics has been looking for the answer to the question: where can one apply the theoretical foundations of science. It is precisely applied physics that makes it possible in practice to use scientific discoveries, since this section underlies engineering, all inventions. For example, nuclear physics helped create nuclear energy, and the use of electricity would be impossible without knowledge of solid-state physics. Applied physics has many connections with other sciences, such as chemistry, biology, etc.
Basic physical theories
Today there are many sections of physics, which cover almost all natural phenomena. Here are the main ones:
- Classical mechanics is a branch of physics that studies changes in body position in space, looking for the causes that cause it.Mechanics is based on the theory of I. Newton. Classical mechanics is divided into statics (studies the balance of bodies), kinematics (studies the geometry of the movement of bodies) and dynamics (studies the causes of the movement of bodies).
- Thermodynamics is a branch of physics that studies the properties of macroscopic systems, methods and ways of energy transformation in these systems. All thermodynamics is divided into equilibrium (classical) and non-equilibrium.
- Theory of Electromagnetism - studies the interaction between particles with an electric charge. This includes such subsections as electrostatics, electrodynamics, magnetic hydrodynamics, and others.
- Quantum mechanics is a branch of theoretical physics that describes physical phenomena whose action is comparable to a very small quantity — the Planck constant.
- Molecular physics is a section that studies the properties of matter at the level of molecules and atoms.
- The theory of relativity is a modern theory that studies space and time in the context of physical processes.
- Nuclear physics - studies the physical properties of radioactive substances.
- Optics is a branch of physics that studies phenomena that are associated with the propagation of electromagnetic waves, in particular light, X-rays, and others.