User:Saeed.Veradi/Definition of Physics

The definition, in the lead section of a Wikipedia article, is not usually copy/paste a definition from one reliable source. see: mathematics, Chemistry, Biology, ... Instead, use definitions from many sources. But nobody will combine them for us. we have to do it ourselves:
 * 1) Analyzing existing definitions
 * 2) Analyzing their key concepts
 * 3) Analyzing their combination
 * 4) Combining key concepts

Analyzing existing definitions
The definition of physics is a ontological matter, not a scientific one. But scientists can really help.

Physics: The Science of measurement.
 * I remember it. but I didn't find it in the source.

Physics: The scientific study of matter, energy, space, and time, and of the relations between them.
 * Mass, energy and length of matter and space are quantities. so is time.
 * Every science studies the relation between different types of it's subject
 * If relation means equation, equations involving quantities are a powerful math tool, used in every science. not just physics.

Dictionary definitions
Physics: The branch of science concerned with the nature and properties of matter and energy. The subject matter of physics, distinguished from that of chemistry and biology, includes mechanics, heat, light and other radiation, sound, electricity, magnetism, and the structure of atoms -
 * Ontology, not science itself, is concerned with nature of things studied in science.
 * properties means quantities.
 * Energy is a quantity.
 * Matter, and atom's structure is the subject of Chemistry, not Physics. Of course, Physical science includes Chemistry.
 * "Mechanics, heat, ..., magnetism" is an extensional definition. such definitions are used in the absence of an intensional definition.

Physics is the scientific study of matter and energy and how they interact with each other.
 * Interaction is the way rules of nature(Physics) affect structure of Matter (Chemistry). it's the subject of chemistry.
 * Energy is just a quantity. matter is a thing. quantities don't interact. it's matter that interacts. interaction involes transfer of energy into/out of matter. thus energy is not what interacts . it's what defines interaction.

Physics: The science of matter and energy and of interactions between the two, grouped in traditional fields such as acoustics, optics, mechanics, thermodynamics, and electromagnetism, as well as in modern extensions including atomic and nuclear physics, cryogenics, solid-state physics, particle physics, and plasma physics.
 * This definition has the same problems as the above dictionary definition.

Analyzing key Concepts
Key concepts are concepts used in most definitions.

Science or study?
 * A scientific study? Studying is a production, not a product. Action, not information.
 * A science? Science both means a field of information, and a study.

So Physics is a science. not just a scientific study.

Matter
 * The existence of matter, God, ... is studied in Ontology.
 * The quantities of matter, light, and ,... are studied in Physics.
 * The structure of matter, and only matter, is studied in Chemistry.

So, The concept of matter should be used in defining Chemistry, But not Physics and Ontology. but "quantities of matter like mass, energy, ..." is a helpful term for defining physics.

Space
 * The existence of Space is studied in Ontology.
 * The quantities that describes space, like length, number of dimensions, curvature of space, ... are studied in Physics.

Energy
 * In Ontology, the existence and essence of energy has become a highly important concept.
 * So Physics is defineately not the study of what energy is (in essence).
 * In Physics, Energy is an important quantity. just like time, length, mass, Temperature, charge, ... but it's just a quantity.
 * So defining Physics as "the science of quantities" is more intensional, while "the science of Energy, time, length, and ..." is more extensional

measurement
 * Good concept. No Prior or Prerequisite field of Physics uses measurement.
 * Not a good subject. The science of measurement is Metrology. Physics is theoretical, while Metrology is a practical field that uses Physics and Chemistry.

and all dependent fields, use Physical units. they also use Physics quantities to define their own quantities.

Combining key concepts
Here are some good combinations:
 * "Quantities of space like lenght and time"
 * "Quantities of matter like energy and mass". electrical charge, charm, strange are also good.
 * The best is both: "Quantities of space and matter. like lenght, time, energy, mass and charge.

Combined definition

 * 1) In the first bold words: We indicate different names of the concept. like: Physics, Biology, Sociology
 * 2) In the first sentence: Indicating the subject of science. Example: Mathematics is the study of patterns. )
 * 3) for the first independent sentence we do word choice for the intensional definition.
 * 4) Choosing the order of the words in that definition.
 * 5) In the first paragraph we provide the extensional definition.
 * 6) In the next paragraph we explain things that the existing definitions can't explain, using reliable source.

So a good Wikipedia definition can't just fall out of a source.

Step one: What are the names of this science? ==

In english, only Physics. Physical science, Natural science, Natural Philosophy, and Philosophy were it's ancestors. but they are different. See: Physics

Step two: What's the subject of physics? To answer that, Fill in the blanks. Physics is the science of _____. or Physics is the study of _____.

When no source can tell us, we have to chose between the suggestions in different sources.

Incomplete, being written