1. Physics is an experimental subject, so there must be experiments.

2. Physical observation is very important, and astronomy is actually a field of physics from the content of research.

3. Physics also needs mathematical tools. If there were no non-Euclidean geometry, there would be no relativistic equation. Relativity may be limited to a conjecture and cannot be verified by experiments.

Based on experimental phenomena, theoretical physics studies the basic laws of motion of elementary particles, nuclei, atoms, molecules, plasma and condensed matter with theoretical methods and models, and solves the basic theoretical problems raised by the discipline itself and high-tech exploration.

The research scope includes particle physics theory, nucleus theory, condensed matter theory, statistical physics, photonics theory, atomic and molecular theory, plasma theory, quantum field theory and quantum mechanics, gravity theory, mathematical physics, theoretical biophysics, nonlinear physics, computational physics and so on.

Extended data:

Physics doesn't study the mechanism of natural phenomena (or at all). We can only feel the laws of nature in some phenomena and try to explain anything that happens in nature with these laws. Our limited intelligence is always trying to understand and change nature, which is the goal pursued by physics and even all natural sciences.

Related sciences based on physics: chemistry, astronomy, physical geography, etc.

The method and scientific attitude of physics: putting forward a proposition → theoretical explanation → theoretical prediction → experimental verification → theoretical correction.

Modern physics is a precise science combining theory with experiment, and its production process is as follows:

① Physical propositions are generally extracted from new observed facts or experimental facts, or derived from existing principles;

② First, try to explain propositions, logical reasoning and mathematical calculus with known theories. If the existing theory cannot be perfectly explained, it is necessary to modify the original model or put forward a brand-new theoretical model;

④ The new theoretical model must make predictions, and the predictions can be confirmed by experiments;

⑤ All physical theories are ultimately based on observation or experimental facts. When a theory is inconsistent with the experimental facts, it will be revised or overturned.