Physics is very closely related to the other natural sciences, particularly chemistry, the science of molecules and the chemical compounds that they form in bulk. Chemistry draws on many fields of physics, particularly quantum mechanics, thermodynamics and electromagnetism. However, chemical phenomena are sufficiently varied and complex that chemistry is usually regarded as a separate discipline. Nevertheless, it is widely accepted among chemists and physicists that the laws of physics describe at the most fundamental level all chemical interactions.
In fact, many physicists take the position that physics is the only fundamental science. Their argument runs as follows: all sciences--biology, chemistry, geology, etc.--are concerned with matter; all matter is composed of atoms; physics describes the dynamics and internal configurations of atoms. Extension of this physico-centric view can result in profound philosophical consequences. For example, if one accepts that the human brain controls all human behavior, and if one accepts that the brain is composed entirely of atoms whose behavior is completely described by laws of physics, then one may reasonably question whether a person has the free will to control his behavior. Nevertheless it is not the task of physics to answer philosophical questions.
A common goal of theoretical physicists is to reduce the description of the physical world to a minimal set of laws governing a finite set of fundamental constituent elements in the universe. That the physical world can necessarily be completely reduced in such a way is unclear; one could conceive of a world comprised of an infinite variety of particles behaving in accordance with an infinite number of laws, or perhaps behaving entirely randomly on occasion. However, thanks to experimental physicists, physics have been remarkably successful to date at this reduction process, and the reduction trend is evident in the names of some of the proposed theories listed below.
Physics, like other sciences, is often subdivided into categories: theoretical physics and experimental physics or fundamental research and applied physics. Theoretical physicists seek new fundamental knowledge about the universe, using the observations of experimental physicists. Experimental physicists perform experiments designed to be able to decide which theory is true. Experimental physics often finds completely new phenomena with no existing theory, e.g. electromagnetism, radioactivity were discovered this way. Fundamental research quests for the basic structure of nature while applied physicists apply existing knowledge to analyze complex systems in order to use them in practical life and economy. Both fundamental research and applied research has theoretical and experimental aspects. As an example, a particularly fertile area of applied physics is solid-state physics, in which researchers use the more fundamental laws of quantum mechanics and electromagnetism to analyze the behavior of atoms that comprise a solid.
Below is an overview of the major subfields and concepts in physics, followed by a brief outline of the history of physics and its subfields. A more comprehensive list of physics topics is also available.
Since antiquity, people have tried to understand the behavior of matter: why unsupported objects drop to the ground, why different materials have different properties, and so forth. Also a mystery was the character of the universe, such as the form of the Earth and the behavior of celestial objects such as the Sun and the Moon. Several theories were proposed, most of them were wrong. These theories were largely couched in philosophical terms, and never verified by systematic experimental testing. There were exceptions and there are anachronisms: for example, the Greek thinker Archimedes derived many correct quantitative descriptions of mechanics and hydrostatics.
From the 18th century onwards, thermodynamics was developed by Boyle, Young, and many others. In 1733, Bernoulli used statistical arguments with classical mechanics to derive thermodynamic results, initiating the field of statistical mechanics. In 1798, Thompson demonstrated the conversion of mechanical work into heat, and in 1847Joule stated the law of conservation of energy, in the form of heat as well as mechanical energy.
In 1897, Thomson discovered the electron, the elementary particle which carries electrical current in circuits. In 1904, he proposed the first model of the atom, known as the plum pudding model. (The existence of the atom had been proposed in 1808 by Dalton.)
In 1905, Einstein formulated the theory of special relativity, unifying space and time into a single entity, spacetime. Relativity prescribes a different transformation between reference frames than classical mechanics; this necessitated the development of relativistic mechanics as a replacement for classical mechanics. In the regime of low (relative) velocities, the two theories agree. In 1915, Einstein extended special relativity to explain gravity with the general theory of relativity, which replace
Physics is very closely related to the other natural sciences, particularly chemistry, the science of molecules and the chemical compounds that they form in bulk. Chemistry draws on many fields of physics, particularly quantum mechanics, thermodynamics and electromagnetism. However, chemical phenomena are sufficiently varied and complex that chemistry is usually regarded as a separate discipline. Nevertheless, it is widely accepted among chemists and physicists that the laws of physics describe at the most fundamental level all chemical interactions.
In fact, many physicists take the position that physics is the only fundamental science. Their argument runs as follows: all sciences--biology, chemistry, geology, etc.--are concerned with matter; all matter is composed of atoms; physics describes the dynamics and internal configurations of atoms. Extension of this physico-centric view can result in profound philosophical consequences. For example, if one accepts that the human brain controls all human behavior, and if one accepts that the brain is composed entirely of atoms whose behavior is completely described by laws of physics, then one may reasonably question whether a person has the free will to control his behavior. Nevertheless it is not the task of physics to answer philosophical questions.
A common goal of theoretical physicists is to reduce the description of the physical world to a minimal set of laws governing a finite set of fundamental constituent elements in the universe. That the physical world can necessarily be completely reduced in such a way is unclear; one could conceive of a world comprised of an infinite variety of particles behaving in accordance with an infinite number of laws, or perhaps behaving entirely randomly on occasion. However, thanks to experimental physicists, physics have been remarkably successful to date at this reduction process, and the reduction trend is evident in the names of some of the proposed theories listed below.
Physics, like other sciences, is often subdivided into categories: theoretical physics and experimental physics or fundamental research and applied physics. Theoretical physicists seek new fundamental knowledge about the universe, using the observations of experimental physicists. Experimental physicists perform experiments designed to be able to decide which theory is true. Experimental physics often finds completely new phenomena with no existing theory, e.g. electromagnetism, radioactivity were discovered this way. Fundamental research quests for the basic structure of nature while applied physicists apply existing knowledge to analyze complex systems in order to use them in practical life and economy. Both fundamental research and applied research has theoretical and experimental aspects. As an example, a particularly fertile area of applied physics is solid-state physics, in which researchers use the more fundamental laws of quantum mechanics and electromagnetism to analyze the behavior of atoms that comprise a solid.
Below is an overview of the major subfields and concepts in physics, followed by a brief outline of the history of physics and its subfields. A more comprehensive list of physics topics is also available.
Since antiquity, people have tried to understand the behavior of matter: why unsupported objects drop to the ground, why different materials have different properties, and so forth. Also a mystery was the character of the universe, such as the form of the Earth and the behavior of celestial objects such as the Sun and the Moon. Several theories were proposed, most of them were wrong. These theories were largely couched in philosophical terms, and never verified by systematic experimental testing. There were exceptions and there are anachronisms: for example, the Greek thinker Archimedes derived many correct quantitative descriptions of mechanics and hydrostatics.
From the 18th century onwards, thermodynamics was developed by Boyle, Young, and many others. In 1733, Bernoulli used statistical arguments with classical mechanics to derive thermodynamic results, initiating the field of statistical mechanics. In 1798, Thompson demonstrated the conversion of mechanical work into heat, and in 1847Joule stated the law of conservation of energy, in the form of heat as well as mechanical energy.
In 1897, Thomson discovered the electron, the elementary particle which carries electrical current in circuits. In 1904, he proposed the first model of the atom, known as the plum pudding model. (The existence of the atom had been proposed in 1808 by Dalton.)
In 1905, Einstein formulated the theory of special relativity, unifying space and time into a single entity, spacetime. Relativity prescribes a different transformation between reference frames than classical mechanics; this necessitated the development of relativistic mechanics as a replacement for classical mechanics. In the regime of low (relative) velocities, the two theories agree. In 1915, Einstein extended special relativity to explain gravity with the general theory of relativity, which replaces Newton's law of gravitation. In the regime of low masses and energies, the two theories agree.
Physics is very closely related to the other natural sciences, particularly chemistry, the science of molecules and the chemical compounds that they form in bulk. Chemistry draws on many fields of physics, particularly quantum mechanics, thermodynamics and electromagnetism. However, chemical phenomena are sufficiently varied and complex that chemistry is usually regarded as a separate discipline. Nevertheless, it is widely accepted among chemists and physicists that the laws of physics describe at the most fundamental level all chemical interactions.
In fact, many physicists take the position that physics is the only fundamental science. Their argument runs as follows: all sciences--biology, chemistry, geology, etc.--are concerned with matter; all matter is composed of atoms; physics describes the dynamics and internal configurations of atoms. Extension of this physico-centric view can result in profound philosophical consequences. For example, if one accepts that the human brain controls all human behavior, and if one accepts that the brain is composed entirely of atoms whose behavior is completely described by laws of physics, then one may reasonably question whether a person has the free will to control his behavior. Nevertheless it is not the task of physics to answer philosophical questions.
A common goal of theoretical physicists is to reduce the description of the physical world to a minimal set of laws governing a finite set of fundamental constituent elements in the universe. That the physical world can necessarily be completely reduced in such a way is unclear; one could conceive of a world comprised of an infinite variety of particles behaving in accordance with an infinite number of laws, or perhaps behaving entirely randomly on occasion. However, thanks to experimental physicists, physics have been remarkably successful to date at this reduction process, and the reduction trend is evident in the names of some of the proposed theories listed below.
Physics, like other sciences, is often subdivided into categories: theoretical physics and experimental physics or fundamental research and applied physics. Theoretical physicists seek new fundamental knowledge about the universe, using the observations of experimental physicists. Experimental physicists perform experiments designed to be able to decide which theory is true. Experimental physics often finds completely new phenomena with no existing theory, e.g. electromagnetism, radioactivity were discovered this way. Fundamental research quests for the basic structure of nature while applied physicists apply existing knowledge to analyze complex systems in order to use them in practical life and economy. Both fundamental research and applied research has theoretical and experimental aspects. As an example, a particularly fertile area of applied physics is solid-state physics, in which researchers use the more fundamental laws of quantum mechanics and electromagnetism to analyze the behavior of atoms that comprise a solid.
Below is an overview of the major subfields and concepts in physics, followed by a brief outline of the history of physics and its subfields. A more comprehensive list of physics topics is also available.
Since antiquity, people have tried to understand the behavior of matter: why unsupported objects drop to the ground, why different materials have different properties, and so forth. Also a mystery was the character of the universe, such as the form of the Earth and the behavior of celestial objects such as the Sun and the Moon. Several theories were proposed, most of them were wrong. These theories were largely couched in philosophical terms, and never verified by systematic experimental testing. There were exceptions and there are anachronisms: for example, the Greek thinker Archimedes derived many correct quantitative descriptions of mechanics and hydrostatics.
From the 18th century onwards, thermodynamics was developed by Boyle, Young, and many others. In 1733, Bernoulli used statistical arguments with classical mechanics to derive thermodynamic results, initiating the field of statistical mechanics. In 1798, Thompson demonstrated the conversion of mechanical work into heat, and in 1847Joule stated the law of conservation of energy, in the form of heat as well as mechanical energy.
In 1897, Thomson discovered the electron, the elementary particle which carries electrical current in circuits. In 1904, he proposed the first model of the atom, known as the plum pudding model. (The existence of the atom had been proposed in 1808 by Dalton.)
In 1905, Einstein formulated the theory of special relativity, unifying space and time into a single entity, spacetime. Relativity prescribes a different transformation between reference frames than classical mechanics; this necessitated the development of relativistic mechanics as a replacement for classical mechanics. In the regime of low (relative) velocities, the two theories agree. In 1915, Einstein extended special relativity to explain gravity with the general theory of relativity, which replaces Newton's law of gravitation. In the regime of low masses and energies, the two theories agree.
