Dynamics

Encyclopedia

**Dynamics**may refer to:

## Physics and engineering

- Dynamics (mechanics)Dynamics (mechanics)In the field of physics, the study of the causes of motion and changes in motion is dynamics. In other words the study of forces and why objects are in motion. Dynamics includes the study of the effect of torques on motion...

, the time evolution of physical processes- AerodynamicsAerodynamicsAerodynamics is a branch of dynamics concerned with studying the motion of air, particularly when it interacts with a moving object. Aerodynamics is a subfield of fluid dynamics and gas dynamics, with much theory shared between them. Aerodynamics is often used synonymously with gas dynamics, with...

, the study of gases in motion - Analytical dynamicsAnalytical dynamicsIn classical mechanics, analytical dynamics, or more briefly dynamics, is concerned about the relationship between motion of bodies and its causes, namely the forces acting on the bodies and the properties of the bodies...

refers to the motion of bodies as induced by external forces - Anomalous dynamics is the stochastic motionStochastic processIn probability theory, a stochastic process , or sometimes random process, is the counterpart to a deterministic process...

of objects with mean square displacementSecond moment methodIn mathematics, the second moment method is a technique used in probability theory and analysis to show that a random variable has positive probability of being positive...

(*MSD*) that deviates from the relation for normal dynamics,*MSD*~*t*, where*t*is the time the process is seen; Anomalous dynamics are either faster than normal dynamics (*MSD*>*t*) or slower (*MSD*<*t*). - Brownian dynamics, is the occurrence of Langevin dynamicsLangevin dynamicsIn physics, Langevin dynamics is an approach to the mathematical modeling of the dynamics of molecular systems, originally developed by the French physicist Paul Langevin...

in the motion of particles in solution (e.g. a grain in water, as was first seen by Brown); its famous property is,*MSD*~*t*, where*MSD*is the mean square displacementSecond moment methodIn mathematics, the second moment method is a technique used in probability theory and analysis to show that a random variable has positive probability of being positive...

, and*t*is time the process is seen. - File dynamicsFile dynamicsIn chemistry, physics, mathematics and related fields, file dynamics is the diffusion of N identical Brownian hard spheres in a quasi-one-dimensional channel of length L , such that the spheres do not jump one on top of the other, and the average particle's density is approximately fixed...

, stochastic motion of particles in a channel - Flight dynamicsFlight dynamicsFlight dynamics is the science of air vehicle orientation and control in three dimensions. The three critical flight dynamics parameters are the angles of rotation in three dimensions about the vehicle's center of mass, known as pitch, roll and yaw .Aerospace engineers develop control systems for...

, the science of aircraft and spacecraft design - Fluid dynamicsFluid dynamicsIn physics, fluid dynamics is a sub-discipline of fluid mechanics that deals with fluid flow—the natural science of fluids in motion. It has several subdisciplines itself, including aerodynamics and hydrodynamics...

or*hydrodynamics*, the study of fluid flow- Computational fluid dynamicsComputational fluid dynamicsComputational fluid dynamics, usually abbreviated as CFD, is a branch of fluid mechanics that uses numerical methods and algorithms to solve and analyze problems that involve fluid flows. Computers are used to perform the calculations required to simulate the interaction of liquids and gases with...

, a way of studying fluid dynamics using numerical methods

- Computational fluid dynamics
- Fractional dynamicsFractional dynamicsFractional dynamics is a field of study in physics, mechanics, mathematics, and economics investigating the behavior of objects and systems that are described byusing integrations and differentiation of fractional orders, by methods of fractional calculus....

studyies the dynamics with integrations and differentiations of fractional orders (in physics, economics, and related fields) - Molecular dynamicsMolecular dynamicsMolecular dynamics is a computer simulation of physical movements of atoms and molecules. The atoms and molecules are allowed to interact for a period of time, giving a view of the motion of the atoms...

, the study of motion on the molecular level -
**Normal dynamics**, is a stochastic motion having a Gaussian probability density functionProbability density functionIn probability theory, a probability density function , or density of a continuous random variable is a function that describes the relative likelihood for this random variable to occur at a given point. The probability for the random variable to fall within a particular region is given by the...

in position with variance*MSD*that follows,*MSD*~*t*, where*MSD*is the mean square displacementSecond moment methodIn mathematics, the second moment method is a technique used in probability theory and analysis to show that a random variable has positive probability of being positive...

of the process, and*t*is time the process is seen. (**Normal dynamics**and Brownian dynamics are very similar, where the term that is used depends on the field). - Langevin dynamicsLangevin dynamicsIn physics, Langevin dynamics is an approach to the mathematical modeling of the dynamics of molecular systems, originally developed by the French physicist Paul Langevin...

, a mathematical model for stochastic dynamics; used in modeling molecules, yet also the stock market, and other things. The most important feature of Langevin dynamics is having a Gaussian random noise. - Quantum chromodynamicsQuantum chromodynamicsIn theoretical physics, quantum chromodynamics is a theory of the strong interaction , a fundamental force describing the interactions of the quarks and gluons making up hadrons . It is the study of the SU Yang–Mills theory of color-charged fermions...

, a theory of the strong interaction (color force) - Quantum electrodynamicsQuantum electrodynamicsQuantum electrodynamics is the relativistic quantum field theory of electrodynamics. In essence, it describes how light and matter interact and is the first theory where full agreement between quantum mechanics and special relativity is achieved...

, description of how matter and light interact - Relativistic dynamicsRelativistic dynamicsRelativistic dynamics refers to a combination of relativistic and quantum concepts to describe the relationships between the motion and properties of a relativistic system and the forces acting on the system...

, a combination of relativistic and quantum concepts - Single file dynamicsFile dynamicsIn chemistry, physics, mathematics and related fields, file dynamics is the diffusion of N identical Brownian hard spheres in a quasi-one-dimensional channel of length L , such that the spheres do not jump one on top of the other, and the average particle's density is approximately fixed...

, also termed, file dynamicsFile dynamicsIn chemistry, physics, mathematics and related fields, file dynamics is the diffusion of N identical Brownian hard spheres in a quasi-one-dimensional channel of length L , such that the spheres do not jump one on top of the other, and the average particle's density is approximately fixed...

, is the diffusion of particles in a channel - Stellar dynamicsStellar dynamicsStellar dynamics is the branch of astrophysics which describes in a statistical way the collective motions of stars subject to their mutual gravity. The long range of gravity and the slow "relaxation" of stellar systems prevent the use of the methods of statistical physics...

, in astrophysics, a description of the collective motion of stars - System dynamicsSystem dynamicsSystem dynamics is an approach to understanding the behaviour of complex systems over time. It deals with internal feedback loops and time delays that affect the behaviour of the entire system. What makes using system dynamics different from other approaches to studying complex systems is the use...

, the study of the behavior of complex systems - ThermodynamicsThermodynamicsThermodynamics is a physical science that studies the effects on material bodies, and on radiation in regions of space, of transfer of heat and of work done on or by the bodies or radiation...

, the study of the relationships between heat and mechanical energy

- Aerodynamics

## Sociology and psychology

- Group dynamicsGroup dynamicsGroup dynamics refers to a system of behaviors and psychological processes that occur within a social group , or between social groups...

, the study of social group processes - Power dynamics, the dynamics of power, used in sociology
- PsychodynamicsPsychodynamicsPsychodynamics is the theory and systematic study of the psychological forces that underlie human behavior, especially the dynamic relations between conscious motivation and unconscious motivation...

, the study of the underlying psychological forces driving human behaviour - Spiral DynamicsSpiral dynamicsSpiral Dynamics is a theory of human development introduced in the 1996 book Spiral Dynamics by Don Beck and Chris Cowan. The book was based on the theory of psychology professor Clare W. Graves...

, a social development theory - Social dynamicsSocial dynamicsSocial dynamics can refer to the behavior of groups that results from the interactions of individual group members as well to the study of the relationship between individual interactions and group level behaviors...

, the ability of a society to react to changes

## Computer science and mathematics

- Dynamic data structure, a data structure where the data elements may change
- Dynamical systemDynamical systemA dynamical system is a concept in mathematics where a fixed rule describes the time dependence of a point in a geometrical space. Examples include the mathematical models that describe the swinging of a clock pendulum, the flow of water in a pipe, and the number of fish each springtime in a...

, a concept describing a point's time dependency- Symbolic dynamicsSymbolic dynamicsIn mathematics, symbolic dynamics is the practice of modeling a topological or smooth dynamical system by a discrete space consisting of infinite sequences of abstract symbols, each of which corresponds to a state of the system, with the dynamics given by the shift operator...

, a method to model dynamical systems

- Symbolic dynamics
- Dynamic programmingDynamic programmingIn mathematics and computer science, dynamic programming is a method for solving complex problems by breaking them down into simpler subproblems. It is applicable to problems exhibiting the properties of overlapping subproblems which are only slightly smaller and optimal substructure...

, a method of solving complex problems by breaking them down into simpler steps - Dynamic program analysisDynamic program analysisDynamic program analysis is the analysis of computer software that is performed by executing programs built from that software system on a real or virtual processor. For dynamic program analysis to be effective, the target program must be executed with sufficient test inputs to produce interesting...

, a set of methods for analyzing computer software

## Companies

- Arrow DynamicsArrow DynamicsArrow Dynamics was a roller coaster and amusement ride design company based in Clearfield, Utah, United States. In 2002, the company went bankrupt but was quickly bought by fellow amusement ride manufacturer S&S Power to form S&S Arrow. During its peak, Arrow Dynamics was responsible for some of...

, roller coaster designer - Boston DynamicsBoston DynamicsBoston Dynamics is an engineering and robotics design company best known for the development of BigDog, a quadruped robot designed for the U.S. military with funding from DARPA, and DI-Guy, COTS software for realistic human simulation...

, robot designer - Crystal DynamicsCrystal DynamicsCrystal Dynamics is an American video game developer based in the San Francisco Bay Area and founded in 1992 by Judy Lang, Madaline Canepa and Dave Morris...

, video game developer - General DynamicsGeneral DynamicsGeneral Dynamics Corporation is a U.S. defense conglomerate formed by mergers and divestitures, and as of 2008 it is the fifth largest defense contractor in the world. Its headquarters are in West Falls Church , unincorporated Fairfax County, Virginia, in the Falls Church area.The company has...

, defence contractor

## Other

- Dynamics (music)Dynamics (music)In music, dynamics normally refers to the volume of a sound or note, but can also refer to every aspect of the execution of a given piece, either stylistic or functional . The term is also applied to the written or printed musical notation used to indicate dynamics...

, the softness or loudness of a sound or note - Force DynamicsForce DynamicsForce dynamics is a semantic category that describes the way in which entities interact with reference to force. Force Dynamics gained a good deal of attention in cognitive linguistics due to its claims of psychological plausibility and the elegance with which it generalizes ideas not usually...

, a semantic concept about how entities interact with reference to force - Microsoft DynamicsMicrosoft DynamicsMicrosoft Dynamics is a line of enterprise resource planning and customer relationship management software applications developed by Microsoft. Microsoft Dynamics applications are delivered through a network of reselling partners who provide specialized services...

, a line of business software - Neural oscillation in the field of
*neurodynamics*, a rhythmic pattern in the brain - Population dynamicsPopulation dynamicsPopulation dynamics is the branch of life sciences that studies short-term and long-term changes in the size and age composition of populations, and the biological and environmental processes influencing those changes...

, in life sciences, the changes in the composition of a population

## See also

- Power (disambiguation)
- Kinetics (disambiguation)
- Dynamic Host Configuration ProtocolDynamic Host Configuration ProtocolThe Dynamic Host Configuration Protocol is a network configuration protocol for hosts on Internet Protocol networks. Computers that are connected to IP networks must be configured before they can communicate with other hosts. The most essential information needed is an IP address, and a default...