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General description

Physics is the science of matter and how matter interacts. Physics is used to describe the physical universe around us, and to predict how it will behave. Physics is the science concerned with the discovery and characterization of the universal laws which govern matter, movement and forces, and space and time, and other features of the natural world.

Breadth and goals of physics

The sweep of physics is broad, from the tiniest components of matter and the forces that hold it together, to galaxies and even larger structures. There are only four forces that appear to operate over this entire range. However, even these four forces (gravity, electromagnetism, the weak force associated with radioactivity, and the strong force which holds atoms together) are believed to be different aspects of a single force.

Physics is primarily focused on the goal of formulating ever simpler, more general, and more accurate rules that govern the character and behavior of matter and space itself. One of the major goals of physics is the formulation of theories of universal applicability. Therefore, physics can be viewed as the study of those univeral laws which define, at the most fundamental level possible, the behaviour of the physical universe.

Physics uses the scientific method

Physics uses the scientific method. That is, data from experiments and observations are collected. Theories which attempt to explain these data are produced. Physics uses these theories to not only describe physical phenomena, but to model physical systems and predict how these physical systems will behave. These predictions can then be compared to observations or experimental evidence to verify or falsify the theory.

The theories that are well supported by data and are especially simple and general are sometimes called scientific laws. Of course, all theories, including those known as laws, can be replaced by more accurate and more general laws, when a disagreement with data is found.

Physics is Quantitative

Physics is more quantitative than most other sciences. That is, many of the observations in physics are numerical measurements. Most of the theories in physics use mathematics to express their principles. Most of the predictions from these theories are numerical. This is because of the areas which physics has addressed are more amenable to quantitative approaches than other areas. Sciences also tend to become more quantitative with time as they become more highly developed, and physics is one of the older sciences.

Introduction

Fields of physics

Classical physics traditionally included the fields of mechanics, optics, electricity, magnetism, acoustics and thermodynamics. Modern physics is a term normally used to cover fields which rely on quantum theory, including quantum mechanics, atomic physics, nuclear physics, particle physics and condensed matter physics, as well as the more modern fields of general and special relativity. Although this distinction can be commonly found in older writings, it is of limited current significance as quantum effects are now understood to be of importance even in fields previously considered purely classical.

Approaches in physics

There are many approaches to studying physics, and many different kinds of actitivies in physics. There are two main types of activities in physics; the collection of data and the development of theories.

The data in some subfields of physics is amenable to experiment. For example, condensed matter physics and nuclear physics benefit from the ability to perform experiments. Experimental physics focuses mainly on an empirical approach. Sometimes experiments are done to explore nature, and in other cases experiments are performed to produce data to compare with the predictions of theories.

Some other fields in physics like astrophysics and geophysics are primarily observational sciences because most their data has to be collected passively instead of through experimentation. Nevertheless, observational programs in these fields uses many of the same tools and technology that are used in the experimental subfields of physics.

Theoretical physics often uses quantitative approaches to develop the theories that attempt to explain the data. In this way, theoretical physics often relies heavily on tools from mathematics. Theoretical physics often can involve creating quantitative predictions of physical theories, and comparing these predictions quantitatively with data. Theoretical physics sometimes creates models of physical systems before data is available to test and validate these models.

These two main activities in physics, data collection and theory production and testing, draw on many different skills. This has lead to a lot of specialization in physics, and the introduction, development and use of tools from other fields. For example, theoretical physicists apply mathematics and numerical analysis and statistics and probability and computers and computer software in their work. Experimental physicists develop instruments and techniques for collecting data, drawing on engineering and computer technology and many other fields of technology. Often the tools from these other areas are not quite appropriate for the needs of physics, and need to be adapted or more advanced versions have to be produced.

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that deals with the description of the world around us, and attempts to understand how objects interact with each other - colloquially through principles such as forces, energy, action, etc.

This is more commonly heard in more formal or academic settings, and further discussion of these issues are presented in the Introduction section.

Physics is the science concerned with the discovery and characterization of the universal laws which govern matter, energy, space and time.

Physicists formulate these laws as mathematical theories which attempt to model the behaviour of physical systems at some perceived fundamental level.

Physics research is divided into two main branches: experimental physics and theoretical physics. Experimental physics focuses mainly on empirical research, and on the development and testing of theories against practical experiment. Theoretical physics is more closely related to mathematics, and involves generating and working through the mathematical implications of systems of physical theories, even where experimental evidence of their validity may not be immediately available.

Physics is the branch of science whose goal is to understand nature in terms of simple and universal truths. Physicists create theories to describe the underlying laws of nature in a predictive way, and state their theories in the language of mathematics to make them succinct and precise. Traditionally, physics has proceeded by understanding the smallest and simplest components of matter and the interactions between them, and involves ideas such as energy, forces, space, and time. The foundation of physics, like the other sciences, is the scientific method; experimental observation is the ultimate test of any physical theory.

Classical physics traditionally included the fields of mechanics, optics, electricity, magnetism, acoustics and heat. The more recent fields of general and special relativity have also usually been placed within this category. Modern physics is a term normally used to cover fields which rely on quantum theory, including quantum mechanics, atomic physics, nuclear physics, particle physics and condensed matter physics. Although this distinction can be commonly found in older writings, it is of limited current significance as quantum effects are now understood to be of importance even in fields previously considered purely classical.