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Physics (from the Greek, φυσικός (physikos), "natural", and φύσις (physis), "Nature") is the science of Nature in the broadest sense. Physicists study the behavior and properties of matter in a wide variety of contexts, ranging from the sub-microscopic particles from which all ordinary matter is made ( particle physics) to the behavior of the material Universe as a whole ( cosmology).Some of the properties studied in physics are common to all material systems, such as the conservation of energy. Such properties are often referred to as laws of physics. Physics is sometimes said to be the "fundamental science", because each of the other natural sciences ( biology, chemistry, geology, etc.) deals with particular types of material system that obey the laws of physics. For example, chemistry is the science of molecules and the chemicalA chemical compound is a substance formed from two or more elements, with a fixed ratio determining the composition. For example, dihydrogen monoxide ( water, ) is a compound composed of two hydrogen atoms for every oxygen atom. In general, this fixed rats that they form in the bulk. The properties of a chemical are determined by the properties of the underlying molecules, which are accurately described by areas of physics such as quantum mechanicswavefunctions of an electron in a hydrogen atom possessing definite energy (increasing downward: n 1,2,3,. and angular momentum (increasing across: s p d . Brighter areas correspond to higher probability density for a position measurement. The angular mom, thermodynamicsThermodynamics is the physics of energy, heat, work, entropy and the spontaneity of processes. Thermodynamics is closely related to statistical mechanics from which many thermodynamic relationships can be derived. While dealing with processes in which sys, and electromagnetismElectromagnetism is the physics of the electromagnetic field: a field, encompassing all of space, composed of the electric field and the magnetic field. The electric field is produced by stationary electric charges, and gives rise to the electric force, t.
Physics is also closely related to mathematicsMathematics is commonly defined as the study of patterns of structure, change, and space; more informally, one might say it is the study of "figures and numbers". In the formalist view, it is the investigation of axiomatically defined abstract structures. Physical theoriesIn mathematics, a theory is a set of statements closed under logical implication. In mathematical logic, "theory" is the term for a set of well-formed formulae consisting of certain axioms and all theorems provable from said axioms. Godel's incompleteness are almost invariably expressed using mathematical relations, and the mathematics involved is generally more complicated than in the other sciences. The difference between physics and mathematics is that physics is ultimately concerned with descriptions of the material world, whereas mathematics is concerned with abstract patterns that need not have any bearing on it. However, the distinction is not always clear-cut. There is a large area of research intermediate between physics and mathematics, known as mathematical physicsMathematical physics is the study of physics using mathematics. It might be argued that all of theoretical physics is mathematical physics, but in practice, most physics is done on a more intuitive/approximate or even questionable level. Mathematical phys, devoted to developing the mathematical structure of physical theories.
1 Overview of physics research
1.1 Theoretical and experimental physics
The culture of physics research differs from the other sciences in the separation of theoryIn mathematics, a theory is a set of statements closed under logical implication. In mathematical logic, "theory" is the term for a set of well-formed formulae consisting of certain axioms and all theorems provable from said axioms. Godel's incompleteness and experimentIn the scientific method, an experiment is a set of actions and observations, performed to verify or falsify a hypothesis or research a causal relationship between phenomena. The experiment is a cornerstone in empirical approach to knowledge. See the list. Since the 20th century, most individual physicists have specialized in either theoretical physics or experimental physics, and very few physicists have been successful in both forms of research. In contrast, almost all the successful theorists in biology and chemistry have also been experimentalists.
Roughly speaking, theorists seek to develop theories that can explain existing experimental results and successfully predict future results, while experimentalists devise and perform experiments to test theoretical predictions. Although theory and experiment are developed separately, they are strongly dependent on each other. Progress in physics frequently comes about when experimentalists make a discovery that existing theories cannot account for, necessitating the formulation of new theories. In the absence of experiment, theoretical research frequently goes in the wrong direction; this is one of the criticisms that have been levelled against M-theory, a popular theory in high-energy physics for which no practical experimental test has ever been devised.
