Dictionary Definition
matter
Noun
1 that which has mass and occupies space; "an
atom is the smallest indivisible unit of matter" [syn: substance]
2 a vaguely specified concern; "several matters
to attend to"; "it is none of your affair"; "things are going well"
[syn: affair, thing]
3 some situation or event that is thought about;
"he kept drifting off the topic"; "he had been thinking about the
subject for several years"; "it is a matter for the police" [syn:
topic, subject, issue]
4 a problem; "is anything the matter?"
5 (used with negation) having consequence; "they
were friends and it was no matter who won the games"
6 written works (especially in books or
magazines); "he always took some reading matter with him on the
plane" v : have weight; have import, carry weight; "It does not
matter much" [syn: count,
weigh]
User Contributed Dictionary
Pronunciation
- (UK) /ˈmætə/, /"m
Extensive Definition
In science, matter is commonly
defined as the substance of which physical objects are composed, not
counting the contribution of various energy or force-fields,
which are not usually considered to be matter per se (though they
may contribute to the mass
of objects). Matter constitutes much of the observable
universe, although again, light is not ordinarily considered
matter. Unfortunately, for scientific purposes, "matter" is
somewhat loosely defined. It is normally defined as anything that
has mass and takes up space.
Definition
Anything which occupies
space and has mass is known as matter. In
physics, there is no
broad consensus as to an exact definition of matter. Physicists
generally do not use the saying when precision is needed,
preferring instead to speak of the more clearly defined concepts of
mass, energy, and particles.
A possible definition of
matter which at least some physicists use is that matter is
everything that is composed of elementary fermions. These are the
leptons, including the
electron, and the
quarks, including the up
and down quarks of which
protons and neutrons are made. Since
protons, neutrons and electrons combine to form
atoms and molecules, thus they comprise
the bulk substances which make up all ordinary matter. Matter also
includes the various other baryons, but excludes the "true
mesons". The key relevant
property of fermions is that they have half-integral spin (ie, 1/2,
3/2, 5/2,...,etc.) and thus, by the spin-statistics
theorem of quantum
field theory, obey the Pauli
Exclusion Principle, which forbids two fermions from occupying
the same quantum state. This seems to correspond closely to the
more primitive notion that matter is "impenetrable", and takes up
space.
On this view, things which are
not matter include light
(photons), gravitons, mesons (except for the muon, a lepton which was misnamed a
meson before the distinction became clear) and the other gauge
bosons. These all have
half-even spin (0,1,2,...), do not respect the Exclusion Principle,
and so do not occupy space in the same sense. These may all be
regarded as field
quanta, and may be exchanged freely by fermions without the
fermions changing their own statistics, or thus their essential
identity. However, these bosons do always have energy and,
(according to the mass-energy
equivalence of special
relativity) therefore mass, so that under this definition some
particles have mass without being matter: W and Z bosons have rest mass, but are not elementary
fermions. Also, any two
photons which are not
moving parallel to each
other, taken as a system, have an invariant mass. Glueballs have
mass due to their binding
energy, but contain no particle with rest mass, nor any elementary
fermions.
Most of the mass of protons and neutrons comes from the
binding
energy between the quarks, not the masses of the
quarks themselves. One of
the three types of neutrinos may be
massless.
Properties of matter
Quarks combine to
form hadrons. Because of
the principle of color
confinement which occurs in the strong
interaction, quarks never exist unbound from other quarks.
Among the hadrons are the proton and the neutron. Usually these
nuclei are surrounded by a cloud of electrons. A nucleus with as
many electrons as protons is thus electrically neutral and is
called an atom, otherwise
it is an ion.
Leptons do not feel the strong
force and so can exist unbound from other particles. On Earth,
electrons are generally bound in atoms, but it is easy to free
them, a fact which is exploited in the cathode
ray tube. Muons may briefly form bound states known as muonic atoms. Neutrinos feel
neither the strong nor the electromagnetic
interactions. They are never bound to other
particles.
Antimatter
In particle physics and quantum chemistry, antimatter is matter that is composed of the antiparticles of those that constitute normal matter. If a particle and its antiparticle come into contact with each other, the two annihilate; that is, they may both be converted into other particles with equal energy in accordance with Einstein's equation E = mc2. These new particles may be high-energy photons (gamma rays) or other particle–antiparticle pairs. The resulting particles are endowed with an amount of kinetic energy equal to the difference between the rest mass of the products of the annihilation and the rest mass of the original particle-antiparticle pair, which is often quite large. Antimatter is not found naturally on Earth, except very briefly and in vanishingly small quantities (as the result of radioactive decay or cosmic rays). This is because antimatter which came to exist on Earth outside the confines of a suitable physics laboratory would almost instantly meet the ordinary matter that Earth is made of, and be annihilated. Antiparticles and some stable antimatter (such as antihydrogen) can be made in tiny amounts, but not in enough quantity to do more than test a few of its theoretical properties.There is considerable
speculation both in science and science
fiction as to why the observable universe is apparently almost
entirely matter, whether other places are almost entirely
antimatter instead, and what might be possible if antimatter could
be harnessed, but at this time the apparent asymmetry of matter and
antimatter in the visible universe is one of the great
unsolved problems in physics. Possible processes by which it
came about are explored in more detail under baryogenesis.
Dark matter
main Dark matter In cosmology, effects at the largest scales seem to indicate the presence of incredible amounts of dark matter which is not associated with electromagnetic radiation. Observational evidence of the early universe and big bang require that this matter have energy and mass, but is not composed of either elementary fermions (as above) OR gauge bosons. As such, it is composed of particles as yet unobserved in the laboratory (perhaps supersymmetric particles).Exotic matter
See also
References
External links
matter in Arabic:
مادة
matter in Belarusian:
Матэрыя
matter in Bosnian:
Materija
matter in Bulgarian: Материя
(физика)
matter in Catalan:
Matèria
matter in Czech:
Hmota
matter in Welsh:
Mater
matter in Danish: Stof
(fysik)
matter in German:
Materie
matter in Estonian: Aine
(füüsika)
matter in Modern Greek
(1453-): Ύλη
matter in Spanish:
Materia
matter in Esperanto:
Materio
matter in Basque:
Materia
matter in Persian: ماده
(فیزیک)
matter in French:
Matière
matter in Irish:
Damhna
matter in Galician:
Materia
matter in Korean:
물질
matter in Croatian:
Materija
matter in Ido:
Materio
matter in Indonesian:
Materi
matter in Interlingua
(International Auxiliary Language Association):
Materia
matter in Italian: Materia
(fisica)
matter in Hebrew:
חומר
matter in Luxembourgish:
Matière
matter in Lojban:
marji
matter in Hungarian:
Anyag
matter in Macedonian:
Материја
matter in Malayalam:
ദ്രവ്യം
matter in Malay
(macrolanguage): Jirim
matter in Dutch:
Materie
matter in Japanese:
物質
matter in Norwegian:
Materie
matter in Novial:
Materie
matter in Uzbek:
Materiya
matter in Low German:
Materie
matter in Polish: Materia
(fizyka)
matter in Portuguese:
Matéria
matter in Romanian:
Materie
matter in Quechua:
Imayay
matter in Russian: Материя
(физика)
matter in Albanian:
Lënda
matter in Simple English:
Matter
matter in Slovak: Hmota
(fyzika)
matter in Slovenian:
Snov
matter in Serbian:
Материја
matter in Finnish:
Aine
matter in Swedish:
Materia
matter in Tagalog:
Materya
matter in Tamil:
பொருள்
matter in Thai:
สสาร
matter in Vietnamese: Vật
chất
matter in Turkish:
Madde
matter in Ukrainian:
Матерія
matter in Venetian:
Materia
matter in Yiddish:
מאטריאל
matter in Chinese:
物质
Synonyms, Antonyms and Related Words
activities, activity, ado, affair, affairs, air, ambition, amount, amount to something,
amplitude, annoyance, anxiety, argument, article, aspect, aspiration, atom, atomic particles, atoms, autograph, bag, basis, be featured, be prominent,
be somebody, be something, being, besetment, body, bother, brainchild, brute matter,
building block, bulk,
burden, business, calling, can of worms, carry
weight, case, cause, chapter, chemical element,
chyle, circumstance, colostrum, commerce, complication, component, composed matter,
composition,
computer printout, concern, concernment, condition, consequence, consideration, constituent, content, context, copy, core, count, cut ice, cut some ice,
datum, dead matter,
detail, difficulty, dilemma, disadvantage, discharge, distillate, distillation, document, doing, draft, earth, edited version, element, elementary particle,
elementary unit, elixir,
employ, employment, engrossment, enigma, enterprise, entity, episode, essay, essence, essentials, event, evil, extent, fabric, facet, fact, factor, fair copy, fester, festering, fiction, final draft, finished
version, fire, first draft,
flimsy, focus of
attention, focus of interest, force, function, fundamental particle,
get top billing, gist,
gleet, goal, great ado, grievance, ground, guiding light, guiding
star, head, headache, heading, heart, holograph, humor, hyle, hypostasis, ichor, ideal, implication, import, importance, incident, incidental, inconvenience, individual, inspiration, instance, intention, interest, issue, item, job, kernel, labor, lachryma, lactation, letter, leukorrhea, literae scriptae,
literary artefact, literary production, literature, live matter,
living issue, lodestar,
lookout, lucubration, lymph, magnitude, main point,
mainspring, manuscript, marrow, mass, material, material world,
materiality, matter
in hand, mattering,
mean, meaning, meaningfulness, measure, measurement, meat, medium, milk, minor detail, minutia, minutiae, molecule, moment, monad, motif, motive, mucor, mucus, natural world, nature, neighborhood, nonfiction, nub, numbers, object, occasion, occupation, occurrence, opus, order, original, paper, parchment, particular, peccant humor,
peck of troubles, penscript, phlegm, physical world, piece, piece of writing, pith, play, plenum, poem, point, point at issue, point in
question, predicament, principle, printed matter,
printout, problem, proceeding, production, purport, purulence, pus, puzzle, quandary, quantity, quantum, question, quintessence, range, rankle, rankling, reading matter,
reason, recension, regard, respect, rheum, ripen, rubric, run, running, sake, saliva, sanies, sap, score, screed, scrip, script, scrive, scroll, sea of troubles, second
draft, sense, serous
fluid, serum, service, significance, signification, signify, situation, snot, soul, source, spirit, spring, stand out, standing
matter, star, strength, stuff, subject, subject matter, subject
of thought, substance,
substratum, sum, sum and substance, suppurate, suppuration, sweat, tangible, tear, teardrop, tell, text, the four elements, the
whites, the written word, theme, thing, to-do, topic, transaction, transcript, transcription, trouble, tune, typescript, ulterior motive,
undertaking, unit of
being, upset, upshot, urine, version, vicinity, vocation, water, weep, weigh, weight, whole, work, worry, writing