Physics


Physics is the most basic and most general of the physical and natural sciences. It deals with the fundamental laws and regularities of nature, including laws of motion, energy, heat, electricity, magnetism, light, and the ultimate structure and composition of matter. It is not necessarily the easiest, most important, or even the most useful area of knowledge. Although it is often and fruitfully assumed that all things that can be observed can be reduced ultimately to physical laws as they are now understood, this remains an assumption. The "dark matter" of astronomy and the neutrinos of particle physics are two forms of matter which are nearly inaccessible to physical study because their interactions with ordinary matter are so weak at the scales physicists can easily observe and control. The subject matter of physics is simple compared to many other areas. Atoms are far simpler than human beings, let alone the fullness of their lives or human societies. The difficulty is that physical laws and regularities are usually expressed using the language of mathematics. The application of physics to natural phenomena may be so complex and involve so many unknowns that other methods of study become more practical. This is especially the case in dealing with human activities.	Sapience Home Site Map About Sapience Science Structure of Matter Quantum physics Relativity Electromagnetism Thermodynamics Mechanics
Nevertheless, these fundamental laws can be applied to understanding of all other natural sciences, including particular substances and the changes they undergo, the visible heavens, the earth, and living things. This knowledge is applied in the invention and use of machines and technology, so that physics is essential in all branches of engineering. Physics is here divided into areas of structure of matter, quantum physics, relativity theory, electromagnetism, thermodynamics, and mechanics. Modern physics includes exotic forms of matter and the structure of matter at molecular, atomic, and subatomic scales, quantum physics, and relativity. Classical physics includes the structure of matter at bulk scales, electromagnetism, thermodynamics, and mechanics.

Physics is the most basic and most general of the physical and natural sciences. It deals with the fundamental laws and regularities of nature, including laws of motion, energy, heat, electricity, magnetism, light, and the ultimate structure and composition of matter.

It is not necessarily the easiest, most important, or even the most useful area of knowledge. Although it is often and fruitfully assumed that all things that can be observed can be reduced ultimately to physical laws as they are now understood, this remains an assumption. The "dark matter" of astronomy and the neutrinos of particle physics are two forms of matter which are nearly inaccessible to physical study because their interactions with ordinary matter are so weak at the scales physicists can easily observe and control.

The subject matter of physics is simple compared to many other areas. Atoms are far simpler than human beings, let alone the fullness of their lives or human societies. The difficulty is that physical laws and regularities are usually expressed using the language of mathematics. The application of physics to natural phenomena may be so complex and involve so many unknowns that other methods of study become more practical. This is especially the case in dealing with human activities.

Science

Nevertheless, these fundamental laws can be applied to understanding of all other natural sciences, including particular substances and the changes they undergo, the visible heavens, the earth, and living things. This knowledge is applied in the invention and use of machines and technology, so that physics is essential in all branches of engineering.

Physics is here divided into areas of structure of matter, quantum physics, relativity theory, electromagnetism, thermodynamics, and mechanics. Modern physics includes exotic forms of matter and the structure of matter at molecular, atomic, and subatomic scales, quantum physics, and relativity. Classical physics includes the structure of matter at bulk scales, electromagnetism, thermodynamics, and mechanics.

Structure of Matter

The structure of matter is divided into five principal areas. Exotic matter deals with forms of matter such as degenerate gases, neutronium, and dark matter mentioned earlier. Bulk matter in the form of solids, liquids, and gases is the easiest area to work with. In molecular physics, the structure and behavior of molecules is most accurately described using quantum physics, but can be understood to a considerable extent using concepts of classical physics. Atomic and molecular physics are claimed by both physics and chemistry. The distinction observed here is that general laws are considered to belong to physics, while particular kinds of atoms and molecules are assigned to chemistry. Atomic physics deals with the description and behavior of atoms. It requires quantum physics to describe this behavior fully and accurately, although some aspects of it can be explained using more familiar concepts. Subatomic physics deals with the ultimate and finest structure of matter and requires quantum physics to describe except in the vaguest sense.

Quantum Physics

Atlhough most of quantum physics is inaccessible without fairly advanced mathematical training, a few elementary principles including Plank's constant, the particle behavior of radiation, the wave behavior of matter, and Heisenberg's uncertainty principle are mentioned. Quantum physics are primarily visible at the atomic and subatomic scale. Since humans do not directly observe the behavior of matter and radiation at this scale, ordinary experience and intuition fail, and the details of the behavior have to be described using fairly advanced mathematics. Although quantum physics can be extended to include the special theory of relativity, the effects of gravitation are so weak at the atomic and subatomic scale that unified theories which combine quantum physics and general relativity are all more or less speculative and unverified by experiment.

Relativity

This theory was created by Einstein and has been extended by others. Relativity is divided into two major areas: General relativity and special relativity. The general theory of relativity includes the study of gravitation. The special theory of relativity unifies the treatment of electromagnetism and optics with mechanics except for gravitation. The predictions of relativity often seem contrary to intuition and produce various philosophical difficulties, but intuition is shaped by experience at human scales. At these scales, the differences between classical physics and the predictions of relativity are minute or undetectable, and classical methods are usually easier. However, at the scales involving particle physics, or high-precision timekeeping and orbiting satellites, both the special and general theories have been repeatedly verified.

Electromagnetism

Electromagnetism is the study of light, magnetism, and electricity. Optics is the study of light and invisible electromagnetic waves. This depends heavily on the combined laws of magnetism and electricity, although this connection is not obvious to the ordinary observer. The study of optics is also connected to quantum physics. Magnetism is tied closely to electricity, although the connection is not obvious to the ordinary observer. Electricity is divided into two parts: electric current, which deals with electrical charge in motion, and electrostatics, which deals with electrical charge at rest and related laws and quantities.

Thermodynamics

Thermodynamics is the study of heat and temperature and related quantities and laws. Nonclassical thermodynamics extends the laws of thermodynamics to more general cases. Ordinary observations at the human scale are examined in classical thermodynamics. Its basic connections to the structure of matter and mechanics are examined in statistical mechanics.

Mechanics

Mechanics is considered the most basic and fundamental area of physics, and is one of the oldest. It can be subdivided in many ways. Newton's law of gravitation has applications to the study of weight as distinguished from mass, and celestial mechanics, the motions of astronomical bodies. General mechanics, or Continnum mechanics, discusses waves and deals with fluids and deformable bodies. Rigid body mechanics is concerned with dynamic systems, concepts of energy, the descrption of motion, and the sizes and shapes of rigid bodies. Particle mechanics includes collections of particles, elementary concepts of energy, the concept of mass and the causes of motion, and the basic description of motion.


History The prehistory of physics is almost untraceable. Litte is known of its development in antiquity. Recognizable development occurred in classical and medieval times, but the greatest development by far has come in modern times.
Sociology Peoples of the world, communities, and social structure and change can be applied to physics. Peoples of the world Peoples of the world can be examined using nations. Western Civilization has made the greatest contributions to its development, but some Asiatic peoples have also made significant advances. African peoples and American Indian peoples have contributed less. Various nations [such as France, UK, Italy, South Korea, Burma, Ukraine, Colombia, South Africa, Argentina, Spain, Sudan, Tanzania] can be connected. Primarily, Western Civilization including Germany has made most of these contributions. Anglic peoples such as those of the United States have been prominent. Latin peoples such as those of Mexico have been prominent. Lusitanic peoples such as those of Brazil have made relatively few contributions to physics. Northeast European peoples including those of Russia have made significant contributions. Asiatic peoples including those of Thailand have contributed to physics. Middle Eastern peoples such as those of Iran can be connected. Egypt can be considered. Turkey can be considered. South Asian peoples such as those of India, Pakistan, and Bangladesh have contributed slightly. Oriental peoples including those of China and Japan have contributed. Southeast Asian peoples such as those of Vietnam have contributed little. The Southeast Asian Archipelagoes including peoples of Indonesia and the Philippines have contributed fairly little to physics. Contributions from African peoples including those of Congo DR have been minimal. East African peoples including those of Ethiopia seem to have fairly minimal connections to physics. West African peoples such as those of Nigeria seem to have made few connections. Connections of American Indian peoples (Some of which are found in Mexico) have been minimal. Middle American Indian peoples of the southwestern United States seem to have made few contributions. South American Indian peoples such as those of Brazil seem to have made few contributions. North American Indian peoples of the United States seem to have made few connections. Communities Communities such as Tokyo, Seoul, Mexico City, and Delhi can be examined along with peoples they belong to. Social structure and change Social change Particular changes and movements can be connected. The agricultural revolution can be connected. The agrarian revolution including bronze age movements, early iron age movements, late iron age movements, and modernization can be connected. The industrial revolution including early industrial revolution, middle industrial revolution, and late industrial revolution can be connected. Social change factors including institutional change, cultural change, demographic change, and natural change can be connected. Social change processes including innovation, transmission, adaptation, and extinction can be connected. Social types Industrial societies can be connected. Agrarian societies can be connected. Horticultural societies can be connected. Hunting and gathering societies can be connected. Social structure including class structure, institutional structure, cultural structure, and anthropological structure can be connected. Community and regional structure can be connected.
Institutions Religion Particular religions including Abrahamic religion, Asiatic religion, pagan religion, and secularism can be connected. Religious organization including highly structured, fragmented, and loosely structured religion may be connected. Religious practice may be connected. Religious belief can be connected.	Links to related sites Yahoo - Physics - Ask an Expert
Government including particular governments, government activity, goverment structure, and law are connected. Economics including economic systems, industries, and economic activities will also be useful. Education, including the teaching of physics, cultural institutions, physics research, school systems, and particular schools are all closely associated with physics. Physics does not appear to be closely connected to families including marriage, parenting, kinship, and particular families.
Culture Behavioral culture including occupations, recreation and entertainment, and cultural events is also connected to physics. Customs including vital customs, living and dwelling, dress and adornment, social interation, and institutional customs may be useful. Conceptual culture is vital to physics. Philosophy, including discussions of the nature and limits of physical knowledge, is also useful. Applied science is important. Applied social science, accounting, information and computing science, medical science, navigation, and engineering science can be connected. Measurement is probably the most essential area of study. All major branches of mathematics are used quite heavily. Mathematical foundations are not directly used much, but mathematical descriptions of physical objects can be treated as mathematical objects. Various sets and collections are used, mathematical structure is applied, and attempts to put physics on a strict foundation of mathematical logic have been made. Arithmetic is used heavily. Numeric, concrete, approximate, and variant arithmetic are all useful. Algebra, including real and complex algebra, linear algebra, and abstract algebra is also applied. Analysis including mathematical functions, infinite series, differential calculus, integral calculus, differential equations, and advanced analysis is also important in physics. Geometry including geometric foundations, plane euclidean geometry, solid euclidean geometry, and noneuclidean geometry, is also important. and statistics are essential.	Links to related sites Yahoo - Physics Open Directory - Physics Eric Weinstein's treasure trove of physics Physics Central PhysLINK Physics and Astronomy Classification Scheme. Used to classify published research and more familiar than the organization used on this site. Wikipedia - Physics Physics.org PhysicsWeb WWW Virtual Library - Physics
Literature is also significant. Oral tradition is not extremely important, but literary forms, types, and particular works are often important. Graphic arts including drawing, painting, printmaking, photography, and computer graphics is useful, though not parts of it equally so. Language including linguistics, writing, and languages of the world is important in physics. Not all material culture is useful in physics. Miscellanous artifacts seem to be indirectly useful. Clothing and dress are minimally useful. Transportation and communication technology are useful. Foodstuffs are not directly important to physics itself. Buildings including building materials, components, furnishings, finished buildings, and outdoor structures may be useful. Industrial technology including tools, fuels, chemical technology, machines, utilities, and other tehcnology and physical instrumentation is highly valuable.
Anthropology Particular groups may be useful.	Links to related sites
Human geograpy, including Europe, Asia, Africa, North America, South America, and Oceania can be connected somewhat. Human ecology seem to have limited use. Physical anthropology including human dispersion, racial variation, and human origins seems to be weakly connected. Demography seems to be less directly useful, but population change and population structure are controlled by analogies of death, migration, and birth and may be useful. Social foundations of physics and physicists will be significant, and includes principles of social group behavior and types, social control, interaction, and social presentation.
Personal studies Individual biographies will also be significant. Prominent contributors to physics have included:	Links to related sites Yahoo - Physicists
Aristotle Archimedes Galileo Newton Dalton Faraday Maxwell Einstein Psychology including social psychology, personality, disorders, developmental psychology, behavioral patterns, mind, and behavioral elements has an effect on physical observation and research. Various studies of the human body have some importance for physical methods. Form and appearance, life cycle, disease, and human physiology are somewhat weakly connected. Human body systems including structural, vital, reproductive, and control systems can be connectdd somwhat.
Other Sciences In general, physics is considered more fundamental than other sciences, and most of the connections to them involve applications of physics.	Links to related sites Yahoo - Biophysics
Biology includes more applications of physics than fundamental principles. Biohistory may suggest areas of physics. ecology, behavioral ecology, population ecology, community ecology, Systems, evolution, ecosystems, and biogeography may suggest applications of physics. systematics including microbes, protists, plants, fungi, and animals, Organism biology with habitat, tissues, organ systems, form, life cycle, and behavior, Cell biology including cell anatomy, behavior, and types also suggest some areas. Molecular biology including inorganics, small organics, carbohydrates, lipids, proteins, and nucleic acids pose some interesting problems. Earth science also includes more applications of it. Geohistory and Physical geography are not as directly connected as other areas. Principles of atmospheric science including atmospheric structure, meteorology, and climatology, hydrospheric science including oceanography, glaciology, freshwater, and groundwater, and geology including mineralogy, petrology, landforms, geological processes, and interior geology sometimes affect physical experiments. Astronomy Astronomy depends so heavily on physics that these subjects are often studied together, and astronomy has often provided tests for physical theories. Cosmology is particularly used as a check on theorization about general relativity and subatomic physics. Galactic astronomy is used in a similar fashion. Some of the forms of exotic matter, for instance dark matter, are only known from observations at this scale. Stellar astronomy including the interstellar medium, stars, star systems, and astrocartography have also been important. Some of the exotic forms of matter, such as degenerate gases and neutronium, are only known from observations at this scale. Solar System astronomy including the sun, planetary systems, minor bodies, interplanetary medium, and solar system history has been important since ancient times. Chemistry Chemical systems, including organic systems, inorganic systems, gas chemistry, liquid chemistry, and solid chemistry are also sometimes important to physics. Chemical changes are also important. Physical changes such as melting and freezing, boiling and condensation, sublimation, mixing, and separation are often the causes of physical effects. Chemical reactions involving stoichiometry, mechanical rearrangement, electronic rearrangment, chemical kinetics, chemical thermodynamics, and specific reations are sometimes important in physics. Nuclear reactions of radioactive decay, fusion, and fission are often considered part of physics. Physics often deals with particular substances, including mixtures including such as dispersions and solutions. compounds such as inorganic compounds, organic compounds, and acids, bases, and salts can be connected. It also deals with particular elements. There is some use of the periodic table, but particular groups seem to be a bit more useful.

History

The prehistory of physics is almost untraceable. Litte is known of its development in antiquity. Recognizable development occurred in classical and medieval times, but the greatest development by far has come in modern times.

Sociology

Peoples of the world, communities, and social structure and change can be applied to physics.

Peoples of the world

Peoples of the world can be examined using nations. Western Civilization has made the greatest contributions to its development, but some Asiatic peoples have also made significant advances. African peoples and American Indian peoples have contributed less.

Various nations [such as France, UK, Italy, South Korea, Burma, Ukraine, Colombia, South Africa, Argentina, Spain, Sudan, Tanzania] can be connected.

Primarily, Western Civilization including Germany has made most of these contributions. Anglic peoples such as those of the United States have been prominent. Latin peoples such as those of Mexico have been prominent. Lusitanic peoples such as those of Brazil have made relatively few contributions to physics. Northeast European peoples including those of Russia have made significant contributions.

Asiatic peoples including those of Thailand have contributed to physics. Middle Eastern peoples such as those of Iran can be connected. Egypt can be considered. Turkey can be considered. South Asian peoples such as those of India, Pakistan, and Bangladesh have contributed slightly. Oriental peoples including those of China and Japan have contributed. Southeast Asian peoples such as those of Vietnam have contributed little. The Southeast Asian Archipelagoes including peoples of Indonesia and the Philippines have contributed fairly little to physics.

Contributions from African peoples including those of Congo DR have been minimal. East African peoples including those of Ethiopia seem to have fairly minimal connections to physics. West African peoples such as those of Nigeria seem to have made few connections.

Connections of American Indian peoples (Some of which are found in Mexico) have been minimal. Middle American Indian peoples of the southwestern United States seem to have made few contributions. South American Indian peoples such as those of Brazil seem to have made few contributions. North American Indian peoples of the United States seem to have made few connections.

Communities

Communities such as Tokyo, Seoul, Mexico City, and Delhi can be examined along with peoples they belong to.

Social structure and change

Social change

Particular changes and movements can be connected. The agricultural revolution can be connected. The agrarian revolution including bronze age movements, early iron age movements, late iron age movements, and modernization can be connected. The industrial revolution including early industrial revolution, middle industrial revolution, and late industrial revolution can be connected. Social change factors including institutional change, cultural change, demographic change, and natural change can be connected. Social change processes including innovation, transmission, adaptation, and extinction can be connected.

Social types

Industrial societies can be connected. Agrarian societies can be connected. Horticultural societies can be connected. Hunting and gathering societies can be connected.

Social structure including class structure, institutional structure, cultural structure, and anthropological structure can be connected. Community and regional structure can be connected.

Institutions

Religion

Particular religions including Abrahamic religion, Asiatic religion, pagan religion, and secularism can be connected. Religious organization including highly structured, fragmented, and loosely structured religion may be connected. Religious practice may be connected. Religious belief can be connected.

Links to related sites

Yahoo - Physics - Ask an Expert

Government including particular governments, government activity, goverment structure, and law are connected. Economics including economic systems, industries, and economic activities will also be useful. Education, including the teaching of physics, cultural institutions, physics research, school systems, and particular schools are all closely associated with physics. Physics does not appear to be closely connected to families including marriage, parenting, kinship, and particular families.

Culture

Behavioral culture including occupations, recreation and entertainment, and cultural events is also connected to physics. Customs including vital customs, living and dwelling, dress and adornment, social interation, and institutional customs may be useful.

Conceptual culture is vital to physics.

Philosophy, including discussions of the nature and limits of physical knowledge, is also useful.

Applied science is important. Applied social science, accounting, information and computing science, medical science, navigation, and engineering science can be connected. Measurement is probably the most essential area of study.

All major branches of mathematics are used quite heavily. Mathematical foundations are not directly used much, but mathematical descriptions of physical objects can be treated as mathematical objects. Various sets and collections are used, mathematical structure is applied, and attempts to put physics on a strict foundation of mathematical logic have been made. Arithmetic is used heavily. Numeric, concrete, approximate, and variant arithmetic are all useful. Algebra, including real and complex algebra, linear algebra, and abstract algebra is also applied. Analysis including mathematical functions, infinite series, differential calculus, integral calculus, differential equations, and advanced analysis is also important in physics. Geometry including geometric foundations, plane euclidean geometry, solid euclidean geometry, and noneuclidean geometry, is also important. and statistics are essential.

Links to related sites

Yahoo - Physics
Open Directory - Physics
Eric Weinstein's treasure trove of physics
Physics Central
PhysLINK
Physics and Astronomy Classification Scheme. Used to classify published research and more familiar than the organization used on this site.
Wikipedia - Physics
Physics.org
PhysicsWeb
WWW Virtual Library - Physics

Literature is also significant. Oral tradition is not extremely important, but literary forms, types, and particular works are often important.

Graphic arts including drawing, painting, printmaking, photography, and computer graphics is useful, though not parts of it equally so.

Language including linguistics, writing, and languages of the world is important in physics.

Not all material culture is useful in physics. Miscellanous artifacts seem to be indirectly useful. Clothing and dress are minimally useful. Transportation and communication technology are useful. Foodstuffs are not directly important to physics itself. Buildings including building materials, components, furnishings, finished buildings, and outdoor structures may be useful. Industrial technology including tools, fuels, chemical technology, machines, utilities, and other tehcnology and physical instrumentation is highly valuable.

Anthropology

Particular groups may be useful.

Links to related sites

Human geograpy, including Europe, Asia, Africa, North America, South America, and Oceania can be connected somewhat.

Human ecology seem to have limited use. Physical anthropology including human dispersion, racial variation, and human origins seems to be weakly connected. Demography seems to be less directly useful, but population change and population structure are controlled by analogies of death, migration, and birth and may be useful.

Social foundations of physics and physicists will be significant, and includes principles of social group behavior and types, social control, interaction, and social presentation.

Personal studies

Individual biographies will also be significant. Prominent contributors to physics have included:

Links to related sites

Yahoo - Physicists

Psychology including social psychology, personality, disorders, developmental psychology, behavioral patterns, mind, and behavioral elements has an effect on physical observation and research.

Various studies of the human body have some importance for physical methods. Form and appearance, life cycle, disease, and human physiology are somewhat weakly connected. Human body systems including structural, vital, reproductive, and control systems can be connectdd somwhat.

Other Sciences

In general, physics is considered more fundamental than other sciences, and most of the connections to them involve applications of physics.

Links to related sites

Yahoo - Biophysics

Biology includes more applications of physics than fundamental principles. Biohistory may suggest areas of physics. ecology, behavioral ecology, population ecology, community ecology, Systems, evolution, ecosystems, and biogeography may suggest applications of physics. systematics including microbes, protists, plants, fungi, and animals, Organism biology with habitat, tissues, organ systems, form, life cycle, and behavior, Cell biology including cell anatomy, behavior, and types also suggest some areas. Molecular biology including inorganics, small organics, carbohydrates, lipids, proteins, and nucleic acids pose some interesting problems.

Earth science also includes more applications of it. Geohistory and Physical geography are not as directly connected as other areas. Principles of atmospheric science including atmospheric structure, meteorology, and climatology, hydrospheric science including oceanography, glaciology, freshwater, and groundwater, and geology including mineralogy, petrology, landforms, geological processes, and interior geology sometimes affect physical experiments.

Astronomy

Astronomy depends so heavily on physics that these subjects are often studied together, and astronomy has often provided tests for physical theories. Cosmology is particularly used as a check on theorization about general relativity and subatomic physics. Galactic astronomy is used in a similar fashion. Some of the forms of exotic matter, for instance dark matter, are only known from observations at this scale. Stellar astronomy including the interstellar medium, stars, star systems, and astrocartography have also been important. Some of the exotic forms of matter, such as degenerate gases and neutronium, are only known from observations at this scale. Solar System astronomy including the sun, planetary systems, minor bodies, interplanetary medium, and solar system history has been important since ancient times.

Chemistry

Chemical systems, including organic systems, inorganic systems, gas chemistry, liquid chemistry, and solid chemistry are also sometimes important to physics.

Chemical changes are also important. Physical changes such as melting and freezing, boiling and condensation, sublimation, mixing, and separation are often the causes of physical effects. Chemical reactions involving stoichiometry, mechanical rearrangement, electronic rearrangment, chemical kinetics, chemical thermodynamics, and specific reations are sometimes important in physics. Nuclear reactions of radioactive decay, fusion, and fission are often considered part of physics.

Physics often deals with particular substances, including mixtures including such as dispersions and solutions. compounds such as inorganic compounds, organic compounds, and acids, bases, and salts can be connected. It also deals with particular elements. There is some use of the periodic table, but particular groups seem to be a bit more useful.

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