TheInfoList

In
physics Physics is the that studies , its , its and behavior through , and the related entities of and . "Physical science is that department of knowledge which relates to the order of nature, or, in other words, to the regular succession of eve ...

, motion is the phenomenon in which an object changes its position over time. Motion is mathematically described in terms of
displacement Displacement may refer to: Physical sciences Mathematics and Physics *Displacement (geometry), is the difference between the final and initial position of a point trajectory (for instance, the center of mass of a moving object). The actual path c ...
,
distance Distance is a numerical measurement ' Measurement is the number, numerical quantification (science), quantification of the variable and attribute (research), attributes of an object or event, which can be used to compare with other objects or eve ...

,
velocity The velocity of an object is the Time derivative, rate of change of its Position (vector), position with respect to a frame of reference, and is a function of time. Velocity is equivalent to a specification of an object's speed and direction ...

,
acceleration In mechanics Mechanics (Greek Greek may refer to: Greece Anything of, from, or related to Greece Greece ( el, Ελλάδα, , ), officially the Hellenic Republic, is a country located in Southeast Europe. Its population is approx ...

,
speed In everyday use and in kinematics Kinematics is a subfield of physics, developed in classical mechanics, that describes the Motion (physics), motion of points, bodies (objects), and systems of bodies (groups of objects) without considerin ...

, and
time Time is the continued sequence of existence and event (philosophy), events that occurs in an apparently irreversible process, irreversible succession from the past, through the present, into the future. It is a component quantity of various me ...

. The motion of a body is observed by attaching a
frame of reference In physics Physics is the that studies , its , its and behavior through , and the related entities of and . "Physical science is that department of knowledge which relates to the order of nature, or, in other words, to the regular s ...

to an observer and measuring the change in position of the body relative to that frame with change in time. The branch of physics describing the motion of objects without reference to its cause is
kinematics Kinematics is a subfield of physics, developed in classical mechanics, that describes the motion Image:Leaving Yongsan Station.jpg, 300px, Motion involves a change in position In physics, motion is the phenomenon in which an object changes it ...

; the branch studying forces and their effect on motion is
dynamics Dynamics (from Greek language, Greek δυναμικός ''dynamikos'' "powerful", from δύναμις ''dynamis'' "power (disambiguation), power") or dynamic may refer to: Physics and engineering * Dynamics (mechanics) ** Aerodynamics, the study o ...
. If an object is not changing relatively to a given frame of reference, the object is said to be ''at rest'', ''motionless'', ''immobile'', ''
stationary In addition to its common meaning, stationary may have the following specialized scientific meanings: Mathematics * Stationary point In mathematics Mathematics (from Ancient Greek, Greek: ) includes the study of such topics as quantity ...
'', or to have a constant or
time-invariant A time-invariant (TIV) system has a time-dependent system function that is not a direct function of time. Such systems are regarded as a class of systems in the field of system analysis. The time-dependent system function is a function of the time- ...
position with reference to its surroundings. As there is no absolute frame of reference, ''
absolute motion Absolute space and time is a concept in physics and philosophy about the properties of the universe. In physics, absolute space and time may be a preferred frameIn theoretical physics, a preferred or privileged frame is usually a special hypothet ...
'' cannot be determined. Thus, everything in the universe can be considered to be in motion. Motion applies to various physical systems: to objects, bodies, matter particles, matter fields, radiation, radiation fields, radiation particles, curvature, and space-time. One can also speak of motion of images, shapes, and boundaries. So, the term motion, in general, signifies a continuous change in the positions or configuration of a physical system in space. For example, one can talk about the motion of a wave or the motion of a quantum particle, where the configuration consists of probabilities of the wave or particle occupying specific positions.

# Laws of motion

In physics, motion of bodies is described through two related sets of
laws Law is a system A system is a group of Interaction, interacting or interrelated elements that act according to a set of rules to form a unified whole. A system, surrounded and influenced by its environment, is described by its bounda ...
of mechanics. Classical mechanics for superatomic (larger than atomic) objects (such as
car A car (or automobile) is a wheeled motor vehicle Electric bicycles parked in Yangzhou's main street, Wenchang Lu. They are a very common way of transport in this city, in some areas almost outnumbering regular bicycles A motor vehicle, also k ...

s,
projectile A projectile is a missile propelled by the exertion of a force In physics, a force is an influence that can change the motion (physics), motion of an Physical object, object. A force can cause an object with mass to change its velocity (e ...

s,
planet A planet is an astronomical body orbiting a star or Stellar evolution#Stellar remnants, stellar remnant that is massive enough to be Hydrostatic equilibrium, rounded by its own gravity, is not massive enough to cause thermonuclear fusion, and ...

s,
cells Cell most often refers to: * Cell (biology), the functional basic unit of life Cell may also refer to: Closed spaces * Monastic cell, a small room, hut, or cave in which a monk or religious recluse lives * Prison cell, a room used to hold peopl ...
, and
human Humans (''Homo sapiens'') are the most abundant and widespread species In biology, a species is the basic unit of biological classification, classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A speci ...

s) and
quantum mechanic Quantum mechanics is a fundamental theory A theory is a reason, rational type of abstraction, abstract thinking about a phenomenon, or the results of such thinking. The process of contemplative and rational thinking is often associated with ...
s for
atom An atom is the smallest unit of ordinary matter In classical physics and general chemistry, matter is any substance that has mass and takes up space by having volume. All everyday objects that can be touched are ultimately composed of ato ...

ic and sub-atomic objects (such as
helium Helium (from el, ἥλιος, helios Helios; Homeric Greek: ), Latinized as Helius; Hyperion and Phaethon are also the names of his father and son respectively. often given the epithets Hyperion ("the one above") and Phaethon ("the shining" ...

,
protons A proton is a subatomic particle, symbol or , with a positive electric charge Electric charge is the physical property of matter that causes it to experience a force when placed in an electromagnetic field. There are two types of electric cha ...
and
electrons The electron is a subatomic particle In physical sciences, subatomic particles are smaller than atom An atom is the smallest unit of ordinary matter In classical physics and general chemistry, matter is any substance that has m ...
). Historically, Newton and Euler formulated three laws of classical mechanics:

## Classical mechanics

Classical mechanics is used for describing the motion of
macroscopic The macroscopic scale is the length scale on which objects or phenomena are large enough to be visible with the naked eye, without magnifying optical instruments. It is the opposite of microscopic The microscopic scale (from , ''mikrós'', "sm ...
objects, from
projectiles A projectile is any object thrown by the exertion of a force. It can also be defined as an object launched into the space and allowed to move free under the influence of gravity and air resistance. Although any object in motion through space (for e ...
to parts of
machinery A machine is any physical system with ordered structural and functional properties. It may represent human-made or naturally occurring device molecular machine A molecular machine, nanite, or nanomachine is a molecular component that produc ...

, as well as
astronomical objects In astronomy Astronomy (from el, ἀστρονομία, literally meaning the science that studies the laws of the stars) is a natural science that studies astronomical object, celestial objects and celestial event, phenomena. It us ...
, such as
spacecraft A spacecraft is a vehicle or machine designed to fly in outer space. A type of artificial satellite alt=, A full-size model of the Earth observation satellite ERS 2 ">ERS_2.html" ;"title="Earth observation satellite ERS 2">Earth obse ...

,
planets A planet is an astronomical body orbit In physics, an orbit is the gravitationally curved trajectory of an physical body, object, such as the trajectory of a planet around a star or a natural satellite around a planet. Normally, orbit r ...

,
star A star is an astronomical object consisting of a luminous spheroid of plasma Plasma or plasm may refer to: Science * Plasma (physics), one of the four fundamental states of matter * Plasma (mineral) or heliotrope, a mineral aggregate * Quark ...

s, and
galaxies A galaxy is a gravitationally bound system of star A star is an astronomical object consisting of a luminous spheroid of plasma (physics), plasma held together by its own gravity. The List of nearest stars and brown dwarfs, nearest star to ...

. It produces very accurate results within these domains, and is one of the oldest and largest scientific descriptions in
science Science () is a systematic enterprise that builds and organizes knowledge Knowledge is a familiarity or awareness, of someone or something, such as facts A fact is something that is truth, true. The usual test for a statement of ...

,
engineering Engineering is the use of scientific principles to design and build machines, structures, and other items, including bridges, tunnels, roads, vehicles, and buildings. The discipline of engineering encompasses a broad range of more speciali ...

, and
technology Technology ("science of craft", from Greek#REDIRECT Greek Greek may refer to: Greece Anything of, from, or related to Greece Greece ( el, Ελλάδα, , ), officially the Hellenic Republic, is a country located in Southeast Europe. I ...

. Classical mechanics is fundamentally based on
Newton's laws of motion Newton's laws of motion are three law Law is a system A system is a group of Interaction, interacting or interrelated elements that act according to a set of rules to form a unified whole. A system, surrounded and influenced by its ...
. These laws describe the relationship between the forces acting on a body and the motion of that body. They were first compiled by
Sir Isaac Newton Sir Isaac Newton (25 December 1642 – 20 March 1726/27) was an English mathematician A mathematician is someone who uses an extensive knowledge of mathematics Mathematics (from Greek: ) includes the study of such topics a ...

in his work ''
Philosophiæ Naturalis Principia Mathematica (from Latin Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally spoken in the area around Rome, known as Latium. Through the power of the Roman Republic, it bec ...
'', first published on July 5, 1687. Newton's three laws are: # A
body Body may refer to: In science * Physical body, an object in physics that represents a large amount, has mass or takes up space * Body (biology), the physical material of an organism * Body plan, the physical features shared by a group of animals ...
at rest will remain at rest, and a body in motion will remain in motion unless it is acted upon by an external force.
(This is known as the law of
inertia Inertia is the resistance of any physical object Object may refer to: General meanings * Object (philosophy), a thing, being, or concept ** Entity, something that is tangible and within the grasp of the senses ** Object (abstract), an ob ...

.) # Force is equal to the change in momentum (mv) per change in time. For a constant mass, force equals mass times acceleration (F = ma). # For every action, there is an equal and opposite reaction.
i.e. whenever one body exerts a force F onto a second body, (in some cases, which is standing still) the second body exerts the force −F back onto the first body. F and −F are equal in magnitude and opposite in direction. So, the body which exerts F will be pushed backwards. Newton's three laws of motion were the first to accurately provide a mathematical model for understanding
orbit In celestial mechanics, an orbit is the curved trajectory of an physical body, object such as the trajectory of a planet around a star, or of a natural satellite around a planet, or of an satellite, artificial satellite around an object or po ...

ing bodies in
outer space Outer space, commonly shortened to space, is the expanse that exists beyond Earth Earth is the third planet from the Sun and the only astronomical object known to harbour and support life. 29.2% of Earth's surface is land consisting ...
. This explanation unified the motion of celestial bodies and motion of objects on earth.

## Equations of Motion

; Translational motion In translational motion, the driving force ''F'' is counterbalanced by a resisting force ''F''r set up by the driven machine and by an inertia force ''Ma'' arising from the change in speed, or $\vec-\vec=M\vec=M$ (1) where the mass ''M'' is expressed in kg. the velocity ''v'' in m/sec, the acceleration ''a'' in m/sec2, and the force ''F'' in newtons (N). ; Oscillatory motion A motion repeating itself is referred to as periodic or oscillatory motion. An object in such motion oscillates about an equilibrium position due to a restoring force or torque. Such force or torque tends to restore (return) the system toward its equilibrium position no matter in which direction the system is displaced. ;Rotational motion In rotational motion, the driving torque ''T''M (usually developed by the electric motor) is counterbalanced by a resisting torque ''T''L (usually developed by the load and referred to as the motor shaft) and by an inertia or dynamic torque ''J d''ω/''dt'', $T_M-T_L=J\operatorname\!\omega/\operatorname\!t$ (2) where the inertia ''J'' is expressed in kg*m2. It is sometimes called flywheel torque or moment and ''T'' is the torque in N*m. The signs to be associated with ''T''M and ''T''L in Eq. (2) depend on the regime of operation of the driving motor and the nature of the load torque. Uniform Motion: When an object moves with a constant speed in a particular direction at regular intervals of time it is known as ''uniform motion.'' For example: a bike moving in a straight line with a constant speed. Equations of Uniform Motion: If $\mathbf$ = final and initial velocity, $t$ = time, and $\mathbf$ = displacement, then: :$\mathbf = \mathbft$ (3)

## Relativistic mechanics

Modern kinematics developed with study of
electromagnetism Electromagnetism is a branch of physics Physics is the that studies , its , its and behavior through , and the related entities of and . "Physical science is that department of knowledge which relates to the order of nature, or, in ...

and refers all velocities ''v'' to their ratio to
speed of light The speed of light in vacuum A vacuum is a space Space is the boundless three-dimensional Three-dimensional space (also: 3-space or, rarely, tri-dimensional space) is a geometric setting in which three values (called paramet ...
''c''. Velocity is then interpreted as
rapidity In Theory of relativity, relativity, rapidity is commonly used as a measure for relativistic velocity. Mathematically, rapidity can be defined as the hyperbolic angle that differentiates two frames of reference in relative motion, each frame being a ...
, the
hyperbolic angle is in ''standard position'' if In mathematics Mathematics (from Ancient Greek, Greek: ) includes the study of such topics as quantity (number theory), mathematical structure, structure (algebra), space (geometry), and calculus, change (mathe ...

φ for which the hyperbolic tangent function tanh φ = ''v''/''c''.
Acceleration In mechanics Mechanics (Greek Greek may refer to: Greece Anything of, from, or related to Greece Greece ( el, Ελλάδα, , ), officially the Hellenic Republic, is a country located in Southeast Europe. Its population is approx ...

, the change of velocity, then changes rapidity according to
Lorentz transformation In physics, the Lorentz transformations are a six-parameter family of Linear transformation, linear coordinate transformation, transformations from a coordinate frame in spacetime to another frame that moves at a constant velocity relative to the ...

s. This part of mechanics is
special relativity In physics Physics is the natural science that studies matter, its Elementary particle, fundamental constituents, its Motion (physics), motion and behavior through Spacetime, space and time, and the related entities of energy and force ...
. Efforts to incorporate
gravity Gravity (), or gravitation, is a by which all things with or —including s, s, , and even —are attracted to (or ''gravitate'' toward) one another. , gravity gives to s, and the causes the s of the oceans. The gravitational attracti ...

into relativistic mechanics were made by W. K. Clifford and
Albert Einstein Albert Einstein ( ; ; 14 March 1879 – 18 April 1955) was a German-born theoretical physicist, widely acknowledged to be one of the greatest physicists of all time. Einstein is known for developing the theory of relativity The theo ...

. The development used
differential geometry Differential geometry is a Mathematics, mathematical discipline that studies the geometry of smooth shapes and smooth spaces, otherwise known as smooth manifolds, using the techniques of differential calculus, integral calculus, linear algebra a ...
to describe a curved universe with gravity; the study is called
general relativity General relativity, also known as the general theory of relativity, is the geometric Geometry (from the grc, γεωμετρία; '' geo-'' "earth", '' -metron'' "measurement") is, with arithmetic, one of the oldest branches of mathema ...
.

## Quantum mechanics

Quantum mechanics Quantum mechanics is a fundamental theory A theory is a reason, rational type of abstraction, abstract thinking about a phenomenon, or the results of such thinking. The process of contemplative and rational thinking is often associated with ...
is a set of principles describing at the atomic level of matter (
molecule A molecule is an electrically Electricity is the set of physical phenomena associated with the presence and motion Image:Leaving Yongsan Station.jpg, 300px, Motion involves a change in position In physics, motion is the phenomenon ...

s and
atom An atom is the smallest unit of ordinary matter In classical physics and general chemistry, matter is any substance that has mass and takes up space by having volume. All everyday objects that can be touched are ultimately composed of ato ...

s) and the
subatomic particle In physical sciences, subatomic particles are smaller than atom An atom is the smallest unit of ordinary matter In classical physics and general chemistry, matter is any substance that has mass and takes up space by having volume. All ...
s (
electron The electron is a subatomic particle (denoted by the symbol or ) whose electric charge is negative one elementary charge. Electrons belong to the first generation (particle physics), generation of the lepton particle family, and are general ...

s,
proton A proton is a subatomic particle, symbol or , with a positive electric charge of +1''e'' elementary charge and a mass slightly less than that of a neutron. Protons and neutrons, each with masses of approximately one atomic mass unit, are collecti ...

s,
neutron The neutron is a subatomic particle, symbol or , which has a neutral (not positive or negative) charge, and a mass slightly greater than that of a proton. Protons and neutrons constitute the nuclei of atoms. Since protons and neutrons behav ...

s, and even smaller
elementary particle In particle physics, an elementary particle or fundamental particle is a subatomic particle that is not composed of other particles. Particles currently thought to be elementary include the fundamental fermions (quarks, leptons, antiquarks, and a ...
s such as
quark A quark () is a type of elementary particle In particle physics, an elementary particle or fundamental particle is a subatomic particle that is not composed of other particles. Particles currently thought to be elementary include the fundam ...

s). These descriptions include the simultaneous wave-like and particle-like behavior of both
matter In classical physics Classical physics is a group of physics theories that predate modern, more complete, or more widely applicable theories. If a currently accepted theory is considered to be modern, and its introduction represented a major ...
and
radiation In physics Physics is the natural science that studies matter, its Elementary particle, fundamental constituents, its Motion (physics), motion and behavior through Spacetime, space and time, and the related entities of energy and f ...

energy as described in the
wave–particle duality Wave–particle duality is the concept in quantum mechanics that every particle or quantum entity may be described as either a particle or a wave. It expresses the inability of the classical physics, classical concepts "particle" or "wave" to ful ...
. In classical mechanics, accurate
measurement Measurement is the quantification (science), quantification of variable and attribute (research), attributes of an object or event, which can be used to compare with other objects or events. The scope and application of measurement are dependen ...

s and
prediction Image:Old Farmer's Almanac 1793 cover.jpg, frame, ''The Old Farmer's Almanac'' is famous in the US for its (not necessarily accurate) long-range weather predictions. A prediction (Latin ''præ-'', "before," and ''dicere'', "to say"), or forecas ...
s of the state of objects can be calculated, such as
location In geography Geography (from Ancient Greek, Greek: , ''geographia'', literally "earth description") is a field of science devoted to the study of the lands, features, inhabitants, and phenomena of the Earth and Solar System, planets. Th ...
and
velocity The velocity of an object is the Time derivative, rate of change of its Position (vector), position with respect to a frame of reference, and is a function of time. Velocity is equivalent to a specification of an object's speed and direction ...

. In quantum mechanics, due to the
Heisenberg uncertainty principle In quantum mechanics, the uncertainty principle (also known as Heisenberg's uncertainty principle) is any of a variety of Inequality (mathematics), mathematical inequalities asserting a fundamental limit to the accuracy with which the values for ...

, the complete state of a subatomic particle, such as its location and velocity, cannot be simultaneously determined. In addition to describing the motion of atomic level phenomena, quantum mechanics is useful in understanding some large-scale phenomenon such as
superfluidity File:Liquid helium Rollin film.jpg, The liquid helium is in the superfluid phase. A thin invisible film creeps up the inside wall of the bowl and down on the outside. A drop forms. It will fall off into the liquid helium below. This will repeat unt ...
,
superconductivity Superconductivity is a set of physical properties observed in certain materials where electrical resistance The electrical resistance of an object is a measure of its opposition to the flow of electric current An electric current is a st ...

, and
biological system A biological system is a complex biological network, network which connects several biologically relevant entities. Biological organization spans several scales and are determined based different structures depending on what the system is. Examples ...
s, including the function of smell receptors and the .

# List of "imperceptible" human motions

Humans, like all known things in the universe, are in constant motion; however, aside from obvious movements of the various external
body Body may refer to: In science * Physical body, an object in physics that represents a large amount, has mass or takes up space * Body (biology), the physical material of an organism * Body plan, the physical features shared by a group of animals ...

parts and
locomotion Locomotion means the act or ability of an entity or person to transport or move oneself from place to place. Locomotion or Loco-Motion may refer to: Motion * Motion (physics) *Specific types of motion ** Animal locomotion *** Terrestrial locomoti ...
, humans are in motion in a variety of ways which are more difficult to
perceive Perception (from the Latin Latin (, or , ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken in the area around Rome, known as Latium. Through the powe ...
. Many of these "imperceptible motions" are only perceivable with the help of special tools and careful observation. The larger scales of imperceptible motions are difficult for humans to perceive for two reasons:
Newton's laws of motion Newton's laws of motion are three law Law is a system A system is a group of Interaction, interacting or interrelated elements that act according to a set of rules to form a unified whole. A system, surrounded and influenced by its ...
(particularly the third) which prevents the feeling of motion on a mass to which the observer is connected, and the lack of an obvious
frame of reference In physics Physics is the that studies , its , its and behavior through , and the related entities of and . "Physical science is that department of knowledge which relates to the order of nature, or, in other words, to the regular s ...

which would allow individuals to easily see that they are moving. The smaller scales of these motions are too small to be detected conventionally with human
sense A sense is a biological system used by an organism for sensation, the process of gathering information about the world and responding to Stimulus (physiology), stimuli. (For example, in the human body, the brain receives signals from the senses ...

s.

## Universe

Spacetime In physics, spacetime is any mathematical model which fuses the three-dimensional space, three dimensions of space and the one dimension of time into a single four-dimensional manifold. Minkowski diagram, Spacetime diagrams can be used to visuali ...
(the fabric of the universe) is expanding meaning everything in the
universe The universe ( la, universus) is all of space and time and their contents, including planets, stars, galaxy, galaxies, and all other forms of matter and energy. The Big Bang theory is the prevailing cosmological description of the development ...

is stretching like a
rubber band A rubber band (also known as an elastic band, gum band or lacky band) is a loop of rubber, usually ring or oval shaped, and commonly used to hold multiple objects together. The rubber band was patented in England on March 17, 1845 by Stephen Pe ...
. This motion is the most obscure as it is not physical motion as such, but rather a change in the very nature of the universe. The primary source of verification of this expansion was provided by
Edwin Hubble Edwin Powell Hubble (November 20, 1889 – September 28, 1953) was an American astronomer. He played a crucial role in establishing the fields of extragalactic astronomy and observational cosmology. Hubble proved that many objects previously ...
who demonstrated that all galaxies and distant astronomical objects were moving away from Earth, known as
Hubble's law Hubble's law, also known as the Hubble–Lemaître law, is the observation in physical cosmology Physical cosmology is a branch of cosmology concerned with the study of cosmological models. A cosmological model, or simply cosmology, provides ...
, predicted by a universal expansion.

## Galaxy

The
Milky Way Galaxy The Milky Way is the galaxy that includes our Solar System, with the name describing the galaxy's appearance from Earth: a hazy band of light seen in the night sky formed from stars that cannot be individually distinguished by the naked eye. ...

is moving through
space Space is the boundless three-dimensional Three-dimensional space (also: 3-space or, rarely, tri-dimensional space) is a geometric setting in which three values (called parameter A parameter (from the Ancient Greek language, Ancient Gre ...

and many astronomers believe the velocity of this motion to be approximately relative to the observed locations of other nearby galaxies. Another reference frame is provided by the
Cosmic microwave background The cosmic microwave background (CMB, CMBR), in Big Bang The Big Bang Scientific theory, theory is the prevailing cosmological model explaining the existence of the observable universe from the Planck units#Cosmology, earliest known perio ...
. This frame of reference indicates that the Milky Way is moving at around .

## Sun and solar system

The Milky Way is
rotating A rotation is a circular movement of an object around a center (or point) of rotation. The plane (geometry), geometric plane along which the rotation occurs is called the ''rotation plane'', and the imaginary line extending from the center an ...

around its
dense The density (more precisely, the volumetric mass density; also known as specific mass), of a substance is its mass Mass is both a property Property (''latin: Res Privata'') in the Abstract and concrete, abstract is what belongs to or ...

galactic center, thus the
sun The Sun is the star A star is an astronomical object consisting of a luminous spheroid of plasma (physics), plasma held together by its own gravity. The List of nearest stars and brown dwarfs, nearest star to Earth is the Sun. Many othe ...

is moving in a circle within the
galaxy A galaxy is a gravitation Gravity (), or gravitation, is a natural phenomenon by which all things with mass Mass is both a property Property (''latin: Res Privata'') in the Abstract and concrete, abstract is what belongs to or ...

's
gravity Gravity (), or gravitation, is a by which all things with or —including s, s, , and even —are attracted to (or ''gravitate'' toward) one another. , gravity gives to s, and the causes the s of the oceans. The gravitational attracti ...

. Away from the central bulge, or outer rim, the typical stellar
velocity The velocity of an object is the Time derivative, rate of change of its Position (vector), position with respect to a frame of reference, and is a function of time. Velocity is equivalent to a specification of an object's speed and direction ...

is between . All planets and their moons move with the sun. Thus, the solar system is moving.

## Earth

The Earth is
rotating A rotation is a circular movement of an object around a center (or point) of rotation. The plane (geometry), geometric plane along which the rotation occurs is called the ''rotation plane'', and the imaginary line extending from the center an ...

or spinning around its
axis Axis may refer to: Politics *Axis of evil The phrase "axis of evil" was first used by U.S. President George W. Bush in his State of the Union address on January 29, 2002, less than five months after the 9/11 attacks, and often repeated t ...
. This is evidenced by
day The word day has a number of meanings, depending on the context it is used such as of astronomy, physics, and various calendar systems. As a term in physics and astronomy it is approximately the period during which the Earth completes one ro ...

and
night Night (also described as night time, night-time, or nighttime, unconventionally spelled as ''nite'') is the period of :wikt:ambient, ambient darkness from sunset to sunrise during each 24-hour day, when the Sun is below the horizon. The exact ...

, at the equator the earth has an eastward velocity of .Ask an Astrophysicist
NASA Goodard Space Flight Center.
The Earth is also
orbit In celestial mechanics, an orbit is the curved trajectory of an physical body, object such as the trajectory of a planet around a star, or of a natural satellite around a planet, or of an satellite, artificial satellite around an object or po ...

ing around the
Sun The Sun is the star A star is an astronomical object consisting of a luminous spheroid of plasma (physics), plasma held together by its own gravity. The List of nearest stars and brown dwarfs, nearest star to Earth is the Sun. Many othe ...

in an orbital revolution. A complete orbit around the sun takes one
year A year is the orbital period of a planetary body, for example, the Earth, moving in Earth's orbit, its orbit around the Sun. Due to the Earth's axial tilt, the course of a year sees the passing of the seasons, marked by change in weather, the ...
, or about 365 days; it averages a speed of about .

## Continents

The Theory of
Plate tectonic upright=1.35, Diagram of the internal layering of Earth showing the lithosphere above the asthenosphere (not to scale) Plate tectonics (from the la, label=Late Latin Late Latin ( la, Latinitas serior) is the scholarly name for the written ...

s tells us that the
continent A continent is any of several large landmass A landmass, or land mass, is a large region In geography Geography (from Greek: , ''geographia'', literally "earth description") is a field of science devoted to the study of th ...

s are drifting on
convection current Convection is single or Multiphase flow, multiphase fluid flow that occurs Spontaneous process, spontaneously due to the combined effects of material property heterogeneity and body forces on a fluid, most commonly density and gravity (see bu ...
s within the
mantle Mantle may refer to: *Mantle (geology) A mantle is a layer inside a planetary body A planet is an astronomical body Astronomy (from el, ἀστρονομία, literally meaning the science that studies the laws of the stars) is a n ...
causing them to move across the surface of the
planet A planet is an astronomical body orbiting a star or Stellar evolution#Stellar remnants, stellar remnant that is massive enough to be Hydrostatic equilibrium, rounded by its own gravity, is not massive enough to cause thermonuclear fusion, and ...

at the slow speed of approximately per year. However, the velocities of plates range widely. The fastest-moving plates are the oceanic plates, with the
Cocos Plate The Cocos Plate is a young oceanic tectonic plate beneath the Pacific Ocean off the west coast of Central America, named for Cocos Island, which rides upon it. The Cocos Plate was created approximately 23 million years ago when the Farallon Plate b ...
advancing at a rate of per year and the
Pacific Plate The Pacific Plate is an oceanic tectonic plate This is a list of tectonic plates on Earth's surface Earth is the third planet A planet is an astronomical body orbiting a star or Stellar evolution#Stellar remnants, stellar remnant ...
moving per year. At the other extreme, the slowest-moving plate is the
Eurasian Plate The Eurasian Plate is a tectonic plate This is a list of tectonic plates on Earth's surface. Tectonic plates are pieces of Earth's crust and uppermost mantle, together referred to as the lithosphere. The plates are around thick and consist ...
, progressing at a typical rate of about per year.

## Internal body

The human
heart The heart is a muscular MUSCULAR (DS-200B), located in the United Kingdom The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain,Usage is mixed. The Guardian' and Telegraph' use ...

is constantly contracting to move
blood Blood is a body fluid Body fluids, bodily fluids, or biofluids are liquid A liquid is a nearly incompressible In fluid mechanics or more generally continuum mechanics, incompressible flow (isochoric process, isochoric flow) refers t ...

throughout the body. Through larger veins and arteries in the body, blood has been found to travel at approximately 0.33 m/s. Though considerable variation exists, and peak flows in the
venae cavae The venae cavae (; from the Latin Latin (, or , ) is a classical language A classical language is a language A language is a structured system of communication Communication (from Latin ''communicare'', meaning "to share" or ...
have been found between . additionally, the
smooth muscle Smooth muscle is an involuntary non-striated muscle Striated muscle tissue is a muscle tissue Muscle tissue is a soft tissue that composes muscles in animal bodies, and gives rise to muscles' ability to contract. It is also referred to as myo ...

s of hollow internal
organs An organ is a group of tissues with similar functions. Plant life and animal life rely on many organs that co-exist in organ systems. A given organ's tissues can be broadly categorized as parenchyma Parenchyma () is the bulk of functional ...

are moving. The most familiar would be the occurrence of
peristalsis Peristalsis is a contraction and relaxation of s that propagates in a down a tube, in an direction. Peristalsis is progression of coordinated contraction of involuntary circular muscles, which is preceded by a simultaneous contraction of the ...

which is where digested
food Food is any substance consumed to provide Nutrient, nutritional support for an organism. Food is usually of plant, animal or Fungus, fungal origin, and contains essential nutrients, such as carbohydrates, fats, protein (nutrient), proteins, vi ...

is forced throughout the
digestive tract The gastrointestinal tract (GI tract, digestive tract, alimentary canal) is the tract or passageway of the digestive system that leads from the mouth to the anus. The GI tract contains all the major organ (biology), organs of the digestive syst ...
. Though different foods travel through the body at different rates, an average speed through the human
small intestine The small intestine or small bowel is an organ (anatomy), organ in the human gastrointestinal tract, gastrointestinal tract where most of the #Absorption, absorption of nutrients from food takes place. It lies between the stomach and large intes ...

is . The human
lymphatic system The lymphatic system, or lymphoid system, is an in vertebrates that is part of the and the . It is made up of a large network of lymph, s, lymph nodes, lymphatic or lymphoid organs, and lymphoid tissues. The vessels carry a clear fluid called ...

is also constantly causing movements of excess
fluids In physics Physics (from grc, φυσική (ἐπιστήμη), physikḗ (epistḗmē), knowledge of nature, from ''phýsis'' 'nature'), , is the natural science that studies matter, its Motion (physics), motion and behavior through ...

,
lipids In biology Biology is the natural science that studies life and living organisms, including their anatomy, physical structure, Biochemistry, chemical processes, Molecular biology, molecular interactions, Physiology, physiological mechanis ...

, and immune system related products around the body. The lymph fluid has been found to move through a lymph capillary of the
skin Skin is the layer of usually soft, flexible outer tissue covering the body of a vertebrate animal, with three main functions: protection, regulation, and sensation. Other cuticle, animal coverings, such as the arthropod exoskeleton, have differ ...

at approximately 0.0000097 m/s.

## Cells

The
cells Cell most often refers to: * Cell (biology), the functional basic unit of life Cell may also refer to: Closed spaces * Monastic cell, a small room, hut, or cave in which a monk or religious recluse lives * Prison cell, a room used to hold peopl ...
of the
human body The human body is the structure of a Human, human being. It is composed of many different types of Cell (biology), cells that together create Tissue (biology), tissues and subsequently organ systems. They ensure homeostasis and the life, viabi ...

have many structures which move throughout them.
Cytoplasmic streaming Cytoplasmic streaming, also called protoplasmic streaming and cyclosis, is the flow of the cytoplasm inside the cell, driven by forces from the cytoskeleton. It is likely that its function is, at least in part, to speed up the transport of molecu ...
is a way in which cells move molecular substances throughout the
cytoplasm In cell biology Cell biology (also cellular biology or cytology) is a branch of biology Biology is the natural science that studies life and living organisms, including their anatomy, physical structure, Biochemistry, chemical processes ...
, various
motor proteins 300px, microtubule.html"_;"title="Kinesin_walking_on_a_microtubule">Kinesin_walking_on_a_microtubule_using_protein_dynamics_on_Nanoscopic_scale.html" ;"title="protein_dynamics.html" ;"title="microtubule.html" ;"title="Kinesin walking on a microtub ...
work as
molecular motors is a biological machine that utilizes protein dynamics Molecular motors are natural (biological) or artificial molecular machines that are the essential agents of movement in living organisms. In general terms, a Engine, motor is a device that ...
within a cell and move along the surface of various cellular substrates such as
microtubules Microtubules are polymer A polymer (; Greek ''poly- Poly, from the Greek :wikt:πολύς, πολύς meaning "many" or "much", may refer to: Businesses * China Poly Group Corporation, a Chinese business group, and its subsidiaries: ** Po ...

hydrolysis Hydrolysis (; ) is any chemical reaction in which a molecule of water breaks one or more chemical bonds. The term is used broadly for substitution Substitution may refer to: Arts and media *Chord substitution, in music, swapping one chord fo ...

of
adenosine triphosphate Adenosine triphosphate (ATP) is an organic compound In , organic compounds are generally any s that contain - . Due to carbon's ability to (form chains with other carbon s), millions of organic compounds are known. The study of the properti ...

(ATP), and convert chemical energy into mechanical work.
Vesicles Vesicle may refer to: ; In cellular biology or chemistry * Vesicle (biology and chemistry), a supramolecular assembly of lipid molecules, like a cell membrane * Synaptic vesicle ; In human embryology * Vesicle (embryology), bulge-like features of ...
propelled by motor proteins have been found to have a velocity of approximately 0.00000152 m/s.

## Particles

According to the
laws of thermodynamics The laws of thermodynamics define a group of physical quantities, such as temperature Temperature is a physical quantity that expresses hot and cold. It is the manifestation of thermal energy, present in all matter, which is the source of t ...
, all
particles In the Outline of physical science, physical sciences, a particle (or corpuscule in older texts) is a small wikt:local, localized physical body, object to which can be ascribed several physical property, physical or chemical , chemical properties ...
of
matter In classical physics Classical physics is a group of physics theories that predate modern, more complete, or more widely applicable theories. If a currently accepted theory is considered to be modern, and its introduction represented a major ...
are in constant random motion as long as the
temperature Temperature ( ) is a physical quantity that expresses hot and cold. It is the manifestation of thermal energy Thermal radiation in visible light can be seen on this hot metalwork. Thermal energy refers to several distinct physical concept ...

is above
absolute zero Absolute zero is the lowest limit of the thermodynamic temperature Thermodynamic temperature is the measure of ''absolute temperature'' and is one of the principal parameters of thermodynamics. A thermodynamic temperature reading of zero deno ...
. Thus the
molecule A molecule is an electrically Electricity is the set of physical phenomena associated with the presence and motion Image:Leaving Yongsan Station.jpg, 300px, Motion involves a change in position In physics, motion is the phenomenon ...

s and
atom An atom is the smallest unit of ordinary matter In classical physics and general chemistry, matter is any substance that has mass and takes up space by having volume. All everyday objects that can be touched are ultimately composed of ato ...

s which make up the human body are vibrating, colliding, and moving. This motion can be detected as temperature; higher temperatures, which represent greater
kinetic energy In physics Physics is the that studies , its , its and behavior through , and the related entities of and . "Physical science is that department of knowledge which relates to the order of nature, or, in other words, to the regular ...
in the particles, feel warm to humans who sense the thermal energy transferring from the object being touched to their nerves. Similarly, when lower temperature objects are touched, the senses perceive the transfer of heat away from the body as a feeling of cold.

## Subatomic particles

Within each atom,
electron The electron is a subatomic particle (denoted by the symbol or ) whose electric charge is negative one elementary charge. Electrons belong to the first generation (particle physics), generation of the lepton particle family, and are general ...

s exist in a region around the nucleus. This region is called the
electron cloud In atomic theory Atomic theory is the scientific theory A scientific theory is an explanation of an aspect of the natural world and universe that has been repeatedly tested and verified in accordance with the scientific method The sc ...
. According to of the atom, electrons have a high
velocity The velocity of an object is the rate of change of its position with respect to a frame of reference In physics Physics is the that studies , its , its and behavior through , and the related entities of and . "Physical scie ...
, and the larger the nucleus they are orbiting the faster they would need to move. If electrons 'move' about the electron cloud in strict paths the same way planets orbit the sun, then electrons would be required to do so at speeds which far exceed the speed of light. However, there is no reason that one must confine oneself to this strict conceptualization (that electrons move in paths the same way macroscopic objects do), rather one can conceptualize electrons to be 'particles' that capriciously exist within the bounds of the electron cloud. Inside the
atomic nucleus The atomic nucleus is the small, dense region consisting of s and s at the center of an , discovered in 1911 by based on the 1909 . After the discovery of the neutron in 1932, models for a nucleus composed of protons and neutrons were quickl ...
, the
proton A proton is a subatomic particle, symbol or , with a positive electric charge of +1''e'' elementary charge and a mass slightly less than that of a neutron. Protons and neutrons, each with masses of approximately one atomic mass unit, are collecti ...

s and
neutron The neutron is a subatomic particle, symbol or , which has a neutral (not positive or negative) charge, and a mass slightly greater than that of a proton. Protons and neutrons constitute the nuclei of atoms. Since protons and neutrons behav ...

s are also probably moving around due to the electrical repulsion of the protons and the presence of
angular momentum In , angular momentum (rarely, moment of momentum or rotational momentum) is the rotational equivalent of . It is an important quantity in physics because it is a —the total angular momentum of a closed system remains constant. In three , the ...

of both particles.Chapter 2, Nuclear Science- A guide to the nuclear science wall chart. Berkley National Laboratory.
/ref>

# Light

Light moves at a speed of 299,792,458 m/s, or , in a vacuum. The speed of light in vacuum (or ''c'') is also the speed of all
massless particle In particle physics Particle physics (also known as high energy physics) is a branch of physics Physics is the that studies , its , its and behavior through , and the related entities of and . "Physical science is that department of ...
s and associated
fields File:A NASA Delta IV Heavy rocket launches the Parker Solar Probe (29097299447).jpg, FIELDS heads into space in August 2018 as part of the ''Parker Solar Probe'' FIELDS is a science instrument on the ''Parker Solar Probe'' (PSP), designed to mea ...
in a vacuum, and it is the upper limit on the speed at which energy, matter, information or causation can travel. The speed of light in vacuum is thus the upper limit for speed for all physical systems. In addition, the speed of light is an invariant quantity: it has the same value, irrespective of the position or speed of the observer. This property makes the speed of light ''c'' a natural measurement unit for speed and a fundamental constant of nature.

# Types of motion

*
Simple harmonic motion In mechanics and physics, simple harmonic motion (sometimes abbreviated ) is a special type of Periodic function, periodic motion where the restoring force on the moving object is directly Proportionality (mathematics), proportional to the magni ...

– (e.g., that of a
pendulum A pendulum is a weight suspended from a pivot Pivot may refer to: *Pivot, the point of rotation in a lever A lever ( or ) is a simple machine consisting of a beam or rigid rod pivoted at a fixed hinge, or '':wikt:fulcrum, fulcrum''. A lever ...

). *
Linear motion Linear motion, also called rectilinear motion, is one-dimensional motion Image:Leaving Yongsan Station.jpg, 300px, Motion involves a change in position In physics, motion is the phenomenon in which an object changes its position (mathematics), ...
– motion which follows a straight
linear Linearity is the property of a mathematical relationship (''function Function or functionality may refer to: Computing * Function key A function key is a key on a computer A computer is a machine that can be programmed to carry out se ...

path, and whose
displacement Displacement may refer to: Physical sciences Mathematics and Physics *Displacement (geometry), is the difference between the final and initial position of a point trajectory (for instance, the center of mass of a moving object). The actual path c ...
is exactly the same as its
trajectory A trajectory or flight path is the path that an with in follows through as a function of time. In , a trajectory is defined by via ; hence, a complete trajectory is defined by position and momentum, simultaneously. The mass might be a or ...

. lso_known_as_ lso_known_as_rectilinear_motion">rectilinear_motion.html"_;"title="lso_known_as_rectilinear_motion">lso_known_as_rectilinear_motion*_Reciprocating_motion.html" ;"title="rectilinear_motion.html" ;"title="rectilinear_motion.html" ;"title="lso known as rectilinear motion">lso known as rectilinear motion">rectilinear_motion.html" ;"title="lso known as rectilinear motion">lso known as rectilinear motion* Reciprocating motion">Reciprocal motion * Brownian motion (i.e. the random movement of particles) *
Circular motion In physics Physics is the that studies , its , its and behavior through , and the related entities of and . "Physical science is that department of knowledge which relates to the order of nature, or, in other words, to the regular suc ...

* Rotational motion, Rotatory motion – a motion about a fixed point. (e.g. Ferris wheel). * Curvilinear motion – It is defined as the motion along a curved path that may be planar or in three dimensions. * – (as of the wheel of a bicycle) * Oscillatory – (swinging from side to side) * * Combination (or simultaneous) motions – Combination of two or more above listed motions *
Projectile motion Projectile motion is a form of motion (physics), motion experienced by an object or particle (a projectile) that is projected near the Earth's planetary surface, surface and moves along a curved path under the action of gravity only (in particul ...

– uniform horizontal motion + vertical accelerated motion

# Fundamental motions

*
Linear motion Linear motion, also called rectilinear motion, is one-dimensional motion Image:Leaving Yongsan Station.jpg, 300px, Motion involves a change in position In physics, motion is the phenomenon in which an object changes its position (mathematics), ...
*
Circular motion In physics Physics is the that studies , its , its and behavior through , and the related entities of and . "Physical science is that department of knowledge which relates to the order of nature, or, in other words, to the regular suc ...

*
Oscillation Oscillation is the repetitive variation, typically in time, of some measure about a central value (often a point of Mechanical equilibrium, equilibrium) or between two or more different states. The term ''vibration'' is precisely used to describ ...

*
Wave In physics Physics is the that studies , its , its and behavior through , and the related entities of and . "Physical science is that department of knowledge which relates to the order of nature, or, in other words, to the regular su ...

*
Relative motion The ''relative velocity'' \vec_ (also \vec_ or \vec_) is the velocity of an object or observer B in the rest frame of another object or observer A. Classical mechanics In one dimension (non-relativistic) We begin with relative motion in the cla ...

* Fundamental motions