The following are examples of

orders of magnitude An order of magnitude is an approximation of the logarithm of a value relative to some contextually understood reference value, usually 10, interpreted as the base of the logarithm and the representative of values of magnitude one. Logarithmic di ...

for different

length Length is a measure of distance. In the International System of Quantities, length is a quantity with dimension distance. In most systems of measurement a base unit for length is chosen, from which all other units are derived. In the Inte ...

s. __TOC__

Overview

Detailed list

To help compare different orders of magnitude, the following list describes various lengths between

1.6 \times 10^

metres and

10^

metres.

Subatomic scale

Atomic to cellular scale

Cellular to human scale

Human to astronomical scale

Astronomical scale

Less than 1 zeptometre

The ' ( SI symbol: ') is a

unit Unit may refer to: Arts and entertainment * UNIT, a fictional military organization in the science fiction television series ''Doctor Who'' * Unit of action, a discrete piece of action (or beat) in a theatrical presentation Music * ''Unit'' (a ...

in the

metric system The metric system is a system of measurement that succeeded the decimalised system based on the metre that had been introduced in France in the 1790s. The historical development of these systems culminated in the definition of the Intern ...

equal to . To help compare different

, this section lists

s shorter than 10⁻²¹ m (1 zm). *1.6 × 10⁻⁵ quectometres (1.6 × 10⁻³⁵ metres) – the Planck length (Measures of distance shorter than this do not make physical sense, according to current theories of

physics Physics is the natural science that studies matter, its fundamental constituents, its motion and behavior through space and time, and the related entities of energy and force. "Physical science is that department of knowledge which rel ...

.) *1 qm – 1 quectometre, the smallest named subdivision of the metre in the

SI base unit The SI base units are the standard units of measurement defined by the International System of Units (SI) for the seven base quantities of what is now known as the International System of Quantities: they are notably a basic set from which all ...

of length, one nonillionth of a metre *1 rm – 1 rontometre, a subdivision of the metre in the

of length, one octillionth of a metre *10 rm – the length of one side of a square whose area is one shed, a unit of target cross section used in

nuclear physics Nuclear physics is the field of physics that studies atomic nuclei and their constituents and interactions, in addition to the study of other forms of nuclear matter. Nuclear physics should not be confused with atomic physics, which studies the ...

*2 ym – the effective cross-section radius of 1

MeV In physics, an electronvolt (symbol eV, also written electron-volt and electron volt) is the measure of an amount of kinetic energy gained by a single electron accelerating from rest through an electric potential difference of one volt in vacuum. ...

neutrino A neutrino ( ; denoted by the Greek letter ) is a fermion (an elementary particle with spin of ) that interacts only via the weak interaction and gravity. The neutrino is so named because it is electrically neutral and because its rest mass ...

s as measured by

Clyde Cowan Clyde Lorrain Cowan Jr (December 6, 1919 – May 24, 1974) was an American physicist, the co-discoverer of the neutrino along with Frederick Reines. The discovery was made in 1956 in the neutrino experiment. Frederick Reines received the Nobel Pr ...

and

Frederick Reines Frederick Reines ( ; March 16, 1918 – August 26, 1998) was an American physicist. He was awarded the 1995 Nobel Prize in Physics for his co-detection of the neutrino with Clyde Cowan in the neutrino experiment. He may be the only scientist i ...

1 zeptometre

The ' ( SI symbol: ') is a

in the

equal to . To help compare different

, this section lists

s between 10⁻²¹ m and 10⁻²⁰ m (1 zm and 10 zm). *2 zm – the upper bound for the width of a

cosmic string Cosmic strings are hypothetical 1-dimensional topological defects which may have formed during a symmetry-breaking phase transition in the early universe when the topology of the vacuum manifold associated to this symmetry breaking was not simp ...

in string theory. *2 zm – radius of effective

cross section Cross section may refer to: * Cross section (geometry) ** Cross-sectional views in architecture & engineering 3D *Cross section (geology) * Cross section (electronics) * Radar cross section, measure of detectability * Cross section (physics) **Ab ...

for a 20

GeV GEV may refer to: * ''G.E.V.'' (board game), a tabletop game by Steve Jackson Games * Ashe County Airport, in North Carolina, United States * Gällivare Lapland Airport, in Sweden * Generalized extreme value distribution * Gev Sella, Israeli-South ...

scattering off a

nucleon In physics and chemistry, a nucleon is either a proton or a neutron, considered in its role as a component of an atomic nucleus. The number of nucleons in a nucleus defines the atom's mass number (nucleon number). Until the 1960s, nucleons w ...

*7 zm – radius of effective cross section for a

250 __NOTOC__ Year 250 ( CCL) was a common year starting on Tuesday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Traianus and Gratus (or, less frequently, year 1003 ''Ab ...

GeV neutrino scattering off a nucleon

10 zeptometres

To help compare different

, this section lists

s between 10⁻²⁰ m and 10⁻¹⁹ m (10 zm and 100 zm).

100 zeptometres

To help compare different

, this section lists lengths between 10⁻¹⁹ m and 10⁻¹⁸ m (100 zm and 1 am). *177 zm –

de Broglie wavelength Matter waves are a central part of the theory of quantum mechanics, being an example of wave–particle duality. All matter exhibits wave-like behavior. For example, a beam of electrons can be diffracted just like a beam of light or a water wav ...

protons A proton is a stable subatomic particle, symbol , H+, or 1H+ with a positive electric charge of +1 ''e'' elementary charge. Its mass is slightly less than that of a neutron and 1,836 times the mass of an electron (the proton–electron m ...

at the

Large Hadron Collider The Large Hadron Collider (LHC) is the world's largest and highest-energy particle collider. It was built by the European Organization for Nuclear Research (CERN) between 1998 and 2008 in collaboration with over 10,000 scientists and hundr ...

(7 TeV as of 2010)

1 attometre

The ' ( SI symbol: ') is a

in the

equal to . To help compare different

, this section lists

s between 10⁻¹⁸ m and 10⁻¹⁷ m (1 am and 10 am). *1 am – sensitivity of the

LIGO The Laser Interferometer Gravitational-Wave Observatory (LIGO) is a large-scale physics experiment and observatory designed to detect cosmic gravitational waves and to develop gravitational-wave observations as an astronomical tool. Two large o ...

detector for

gravitational wave Gravitational waves are waves of the intensity of gravity generated by the accelerated masses of an orbital binary system that propagate as waves outward from their source at the speed of light. They were first proposed by Oliver Heaviside in ...

s *1 am – upper limit for the size of

quark A quark () is a type of elementary particle and a fundamental constituent of matter. Quarks combine to form composite particles called hadrons, the most stable of which are protons and neutrons, the components of atomic nuclei. All common ...

s and

electron The electron (, or in nuclear reactions) is a subatomic particle with a negative one elementary electric charge. Electrons belong to the first generation of the lepton particle family, and are generally thought to be elementary partic ...

10 attometres

To help compare different

, this section lists

s between 10⁻¹⁷ m and 10⁻¹⁶ m (10 am and 100 am). *10 am – range of the weak force

100 attometres

To help compare different

, this section lists lengths between 10⁻¹⁶ m and 10⁻¹⁵ m (100 am and 1 fm). *100 am – all lengths shorter than this distance are not confirmed in terms of size *850 am – approximate proton radius

1 femtometre

The ' ( SI symbol: ') is a

in the

equal to . In

particle physics Particle physics or high energy physics is the study of fundamental particles and forces that constitute matter and radiation. The fundamental particles in the universe are classified in the Standard Model as fermions (matter particles) and ...

, this unit is more commonly called a , also with abbreviation "fm". To help compare different

, this section lists

s between 10⁻¹⁵

metre The metre ( British spelling) or meter ( American spelling; see spelling differences) (from the French unit , from the Greek noun , "measure"), symbol m, is the primary unit of length in the International System of Units (SI), though its p ...

s and 10⁻¹⁴ metres (1 femtometre and 10 fm). *1 fm – diameter of a

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 ...

, approximate range-limit of the

color force Color Force is an American independent film and television production company founded in 2007 by producer and film executive Nina Jacobson after her 2006 termination as president of Disney's Buena Vista Motion Pictures Group. Its films incl ...

carried between

s by

gluon A gluon ( ) is an elementary particle that acts as the exchange particle (or gauge boson) for the strong force between quarks. It is analogous to the exchange of photons in the electromagnetic force between two charged particles. Gluons bi ...

s *1.5 fm – diameter of the

scattering cross section In physics, the cross section is a measure of the probability that a specific process will take place when some kind of radiant excitation (e.g. a particle beam, sound wave, light, or an X-ray) intersects a localized phenomenon (e.g. a particle o ...

of an 11

proton with a target proton *1.75 fm – the effective charge diameter of a proton *2.81794 fm –

classical electron radius The classical electron radius is a combination of fundamental physical quantities that define a length scale for problems involving an electron interacting with electromagnetic radiation. It links the classical electrostatic self-interaction energ ...

*3 fm – approximate range-limit of the nuclear binding force mediated by

meson In particle physics, a meson ( or ) is a type of hadronic subatomic particle composed of an equal number of quarks and antiquarks, usually one of each, bound together by the strong interaction. Because mesons are composed of quark subparticle ...

s *7 fm – the radius of the effective scattering cross section for a gold nucleus scattering a 6

alpha particle Alpha particles, also called alpha rays or alpha radiation, consist of two protons and two neutrons bound together into a particle identical to a helium-4 nucleus. They are generally produced in the process of alpha decay, but may also be pro ...

over 140 degrees

10 femtometres

To help compare different

, this section lists

s between 10⁻¹⁴ m and 10⁻¹³ m (10 fm and 100 fm). *1.75 to 15 fm – Diameter range of the

atomic nucleus The atomic nucleus is the small, dense region consisting of protons and neutrons at the center of an atom, discovered in 1911 by Ernest Rutherford based on the 1909 Geiger–Marsden experiments, Geiger–Marsden gold foil experiment. After th ...

100 femtometres

To help compare different

, this section lists lengths between 10⁻¹³ m and 10⁻¹² m (100 fm and 1 pm). *570 fm – typical distance from the atomic nucleus of the two innermost electrons (electrons in the ''1s'' shell) in the

uranium Uranium is a chemical element with the symbol U and atomic number 92. It is a silvery-grey metal in the actinide series of the periodic table. A uranium atom has 92 protons and 92 electrons, of which 6 are valence electrons. Uranium is weakly ...

atom, the heaviest naturally-occurring atom

1 picometre

The ' ( SI symbol: ') is a

in the

equal to (). To help compare different

this section lists

s between 10⁻¹² and 10⁻¹¹ m (1 pm and 10 pm). *1 pm – distance between

atomic nuclei The atomic nucleus is the small, dense region consisting of protons and neutrons at the center of an atom, discovered in 1911 by Ernest Rutherford based on the 1909 Geiger–Marsden gold foil experiment. After the discovery of the neutron in ...

in a

white dwarf A white dwarf is a stellar core remnant composed mostly of electron-degenerate matter. A white dwarf is very dense: its mass is comparable to the Sun's, while its volume is comparable to the Earth's. A white dwarf's faint luminosity comes ...

*1 pm – reference value of particle displacement in acoustics *2.4 pm – The

Compton wavelength The Compton wavelength is a quantum mechanical property of a particle. The Compton wavelength of a particle is equal to the wavelength of a photon whose energy is the same as the rest energy of that particle (see mass–energy equivalence). It wa ...

of an

*5 pm – shorter

X-ray X-rays (or rarely, ''X-radiation'') are a form of high-energy electromagnetic radiation. In many languages, it is referred to as Röntgen radiation, after the German scientist Wilhelm Conrad Röntgen, who discovered it in 1895 and named it ' ...

wavelengths (approx.)

10 picometres

To help compare different

this section lists

s between 10⁻¹¹ and 10⁻¹⁰ m (10 pm and 100 pm). *25 pm – approximate radius of a helium atom, the smallest neutral atom *50 pm – radius of a hydrogen atom *50 pm –

bohr radius The Bohr radius (''a''0) is a physical constant, approximately equal to the most probable distance between the nucleus and the electron in a hydrogen atom in its ground state. It is named after Niels Bohr, due to its role in the Bohr model of an ...

: approximate radius of a hydrogen atom *~50 pm – best resolution of a high-resolution transmission electron microscope *60 pm – radius of a carbon atom *93 pm – length of a

diatomic carbon Diatomic carbon (systematically named dicarbon and 1λ2,2λ2-ethene), is a green, gaseous inorganic chemical with the chemical formula C=C (also written 2or C2). It is kinetically unstable at ambient temperature and pressure, being removed throug ...

molecule *96 pm – H–O bond length in a

water Water (chemical formula ) is an inorganic, transparent, tasteless, odorless, and nearly colorless chemical substance, which is the main constituent of Earth's hydrosphere and the fluids of all known living organisms (in which it acts as ...

molecule

100 picometres

To help compare different

this section lists

s between 10⁻¹⁰ and 10⁻⁹ m (100 pm and 1 nm; 1 Å and 10 Å). *100 pm – 1

ångström The angstromEntry "angstrom" in the Oxford online dictionary. Retrieved on 2019-03-02 from https://en.oxforddictionaries.com/definition/angstrom.Entry "angstrom" in the Merriam-Webster online dictionary. Retrieved on 2019-03-02 from https://www.m ...

*100 pm –

covalent radius The covalent radius, ''r''cov, is a measure of the size of an atom that forms part of one covalent bond. It is usually measured either in picometres (pm) or angstroms (Å), with 1 Å = 100 pm. In principle, the sum o