From Thales’ first attempt to characterize matter, to Democratic’ deduction that matter ought to reduce to an invariant state, the Ptolemaic astronomy of a crystalline firmament, and Aristotle book Physics (an early book on physics, which attempted to analyze and fine motion from a philosophical point of view), various Greek philosophers advanced their own theories of nature. Physics was known as natural philosophy until the late 18th century. By the 19th century physics was realized as a discipline distinct from philosophy and the other sciences.
Physics, as with the rest of science, relies on philosophy of science to give an adequate description of the scientific method. [18] The scientific method employs a priori reasoning as well as a posteriori reasoning and the use of Bayesian inference to measure the validity of a given theory. 19] The development of physics has answered many questions of early philosophers, but has also raised new questions. Study of the philosophical issues surrounding physics, the philosophy of physics, involves issues such as the nature of space and time, determinism, and metaphysical outlooks such as empiricism, naturalism and realism. 20] Many physicists have written about the philosophical implications of their work, for instance Lovelace, who championed causal determinism,[21] and Erwin ScarГ¶dinner, who wrote on quantum mechanics. [22] The mathematical physicist Roger Penrose as been called a Platonist by Stephen Hawking,[23] a view Penrose discusses in his book, The Road to Reality. [24] Hawking refers to himself as an “unashamed reductionism” and takes issue with Penrose views. [25] Core theories Further information: Branches of physics, Outline of physics Though physics deals with a wide variety of systems, certain theories are used by all physicists.
Each of these theories were experimentally tested numerous times and found correct as an approximation of nature (within a certain domain of validity). For instance, the theory of classical mechanics accurately describes the motion of objects, provided they are much larger than atoms and moving at much less than the speed of light. These theories continue to be areas of active research, and a remarkable aspect of classical mechanics known as chaos was discovered in the 20th century, three centuries after the original formulation of classical mechanics by Isaac Newton (1642-1727).
These central theories are important tools for research into more specialized topics, and any physicist, regardless of his or her specialization, is expected to be literate in statistical mechanics, electromagnetism, and special relativity. Classical physics Main article: Classical physics Classical physics implemented in an acoustic engineering model of sound reflecting from an acoustic diffuser Classical physics includes the traditional branches and topics that were recognized and well-developed before the beginning of the 20th century-?classical mechanics, acoustics, optics, thermodynamics, and electromagnetism.
Classical mechanics is concerned with bodies acted on by forces and bodies in motion and may be divided into static (study of the forces on a body or bodies at rest), kinematics (study of motion without regard to its causes), and Hyannis (study of motion and the forces that affect it); mechanics may also be divided into solid mechanics and fluid mechanics (known together as continuum mechanics), the latter including such branches as hydrostatics, hydrodynamics, aerodynamics, and pneumatics. Acoustics is the study of how sound is produced, controlled, transmitted and received. 26] Important modern branches of acoustics include ultrasonic, the study of sound waves of very high frequency beyond the range of human hearing; biostatistics the physics of animal calls and hearing,[27] and electrostatics, the manipulation of audible sound waves using electronics. 28] Optics, the study of light, is concerned not only with visible light but also with infrared and ultraviolet radiation, which exhibit all of the phenomena of visible light except visibility, e. G. , reflection, refraction, interference, diffraction, dispersion, and popularization of light.
Heat is a form of energy, the internal energy possessed by the particles of which a substance is composed; thermodynamics deals with the relationships between heat and other forms of energy. Electricity and magnetism have been studied as a single branch of physics since the intimate connection teen them was discovered in the early 19th century; an electric current gives rise to a magnetic field and a changing magnetic field induces an electric current. Electrostatics deals with electric charges at rest, electrodynamics with moving charges, and necessitating with magnetic poles at rest.
Modern physics Main article: Modern physics Scarödinner equation History of modern physics Founders[show] Branches[show] Scientists[show] Solely Conference of 1927, with prominent physicists such as Albert Einstein, Werner and Paul Doric. Classical physics is generally concerned with matter and energy on he normal scale of observation, while much of modern physics is concerned with the behavior of matter and energy under extreme conditions or on a very large or very small scale. For example, atomic and nuclear physics studies matter on the smallest scale at which chemical elements can be identified.
The physics of elementary particles is on an even smaller scale, as it is concerned with the most basic units of matter; this branch of physics is also known as high-energy physics because of the extremely high energies necessary to produce many types of particles in large particle accelerators. On this scale, ordinary, commonsense notions of space, time, matter, and energy are no longer valid. The two chief theories of modern physics present a different picture of the concepts of space, time, and matter from that presented by classical physics.
Quantum theory is concerned with the discrete, rather than continuous, nature of many phenomena at the atomic and subatomic level, and with the complementary aspects of particles and waves in the description of such phenomena. The theory of relativity is concerned with the description of phenomena that take place in a frame of reference hat is in motion with respect to an observer; the special theory of relativity is concerned with relative uniform motion in a straight line and the general theory of relativity with accelerated motion and its connection with gravitation.
Both quantum theory and the theory of relativity find applications in all areas of modern physics. Difference between classical and modern physics The basic domains of physics While physics aims to discover universal laws, its theories lie in explicit domains of applicability. Loosely speaking, the laws of classical physics accurately describe yester whose important length scales are greater than the atomic scale and whose motions are much slower than the speed of light.
Outside of this domain, observations do not match their predictions. Albert Einstein contributed the framework of special relativity, which replaced notions of absolute time and space with capacities and allowed an accurate description of systems whose components have speeds approaching the speed of light. Max Planck, Erwin Scarödinner, and others introduced quantum mechanics, a probabilistic notion of particles and interactions that allowed an accurate description of atomic and subatomic scales.
Later, quantum field theory unified quantum mechanics and special relativity. General relativity allowed for a dynamical, curved capacities, with which highly massive systems and the large-scale structure of the universe can be well-described. General relativity has not yet been unified with the other fundamental descriptions; several candidate theories of quantum gravity are being developed. This parabola-shaped lava flow illustrates the application of mathematics in physics -?in this case, Galileo law of falling bodies.
Mathematics and ontology are used in physics. Physics is used in chemistry and cosmology. Prerequisites Mathematics is the language used for compact description of the order in nature, especially the laws of physics. This was noted and advocated by Pythagoras,[29] Plato, [30] and Newton. Physics theories use mathematics[32] to obtain order and provide precise formulas, precise or estimated solutions, quantitative results and predictions. Experiment results in physics are numerical measurements.
Technologies based on mathematics, like computation have made computational physics an active area of research. The distinction between mathematics and physics is clear-cut, but not always obvious, especially in mathematical physics. Ontology is a prerequisite for physics, but not for mathematics. It means physics is ultimately concerned with descriptions of the real world, while mathematics is concerned with abstract patterns, even beyond the real world. Thus physics statements are synthetic, while math statements are analytic.
Mathematics contains hypotheses, while physics contains theories. Mathematics statements have to be only logically true, while predictions of physics statements must match observed and experimental data. The distinction is clear-cut, but not always obvious. For example, mathematical physics is the application of mathematics in physics. Its methods are mathematical, but its subject is physical. [33] The problems in this field start with a “math model of a physical situation” and a “math description of a physical law”.
Every math statement used for solution has a hard-to-find physical meaning. The final mathematical solution has an easier-to-find meaning, because it is what the solver is looking for. Called “the fundamental science” because the subject of study of all branches of natural science like chemistry, astronomy, geology and biology are constrained by saws of physics. [35] For example, chemistry studies properties, structures, and reactions of matter (chemistry’s focus on the atomic scale distinguishes it from physics).
Structures are formed because particles exert electrical forces on each other, properties include physical characteristics of given substances, and reactions are bound by laws of physics, like conservation of energy, mass and charge. Physics is applied in industries like engineering and medicine. Application and influence Archimedes’ screw, a simple machine for lifting The application of physical laws in lifting liquids Main article: Applied physics Applied physics is a general term for physics research which is intended for a particular use.
An applied physics curriculum usually contains a few classes in an applied discipline, like geology or electrical engineering. It usually differs from engineering in that an applied physicist may not be designing something in particular, but rather is using physics or conducting physics research with the aim of developing new technologies or solving a problem. The approach is similar to that of applied mathematics. Applied physicists can also be interested in the use of physics for scientific research. For instance, people irking on accelerator physics might seek to build better particle detectors for research in theoretical physics.
Physics is used heavily in engineering. For example, static, a subfield of mechanics, is used in the building of bridges and other static structures. The understanding and use of acoustics results in sound control and better concert halls; similarly, the use of optics creates better optical devices. An understanding of physics makes for more realistic flight simulators, video games, and movies, and is often critical in forensic investigations. Change with time, physics can be used to study things that would ordinarily be mired n uncertainty.
For example, in the study of the origin of the earth, one can reasonably model earth’s mass, temperature, and rate of rotation, as a function of time allowing one to extrapolate forward and backward in time and so predict prior and future conditions. It also allows for simulations in engineering which drastically speed up the development of a new technology. But there is also considerable interdisciplinary in the physicist’s methods and so many other important fields are influenced by physics, e. G. The fields of economics and psychophysics.
