In philosophy, matter constitutes the formless substratum of all things, which exists only potentially and from which reality is produced. In the sense of content, matter is also used in contrast to form. Philosopher in Meditation (detail), by Rembrandt. ... Content can mean Comfort and a feeling of satisfaction Creations, as in open content or free content. ... Look up form in Wiktionary, the free dictionary. ...

In physics, 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. The first few hydrogen atom electron orbitals shown as cross-sections with color-coded probability density. ... Look up substance in Wiktionary, the free dictionary. ... Force fields are applicable to several categories. ... Mass is a property of a physical object that quantifies the amount of matter and energy it is equivalent to. ... The observable Universe is a term used in cosmology to describe a ball-shaped region of space surrounding the Earth that is close enough that we might observe objects in it. ...

Overview

In physics, a loose definition of matter which corresponds reasonably well to what is colloquially called "matter," is that matter is everything that is constituted of particles called elementary fermions. Matter occupies space and has mass (therefore, by this definition, not all mass is matter, but all matter does have mass). Matter, after it is incorporated into particles within a bulk substance, appears predominantly as atoms, which consist of protons, neutrons, and electrons. The first few hydrogen atom electron orbitals shown as cross-sections with color-coded probability density. ... In particle physics, an elementary particle is a particle of which other, larger particles are composed. ... In particle physics, fermions, (named after Enrico Fermi), are particles with semi-integer spin. ... Space has been an interest for philosophers and scientists for much of human history, and hence it is difficult to provide an uncontroversial and clear definition outside of specific defined contexts. ... Mass is a property of a physical object that quantifies the amount of matter and energy it is equivalent to. ... In physics, a particle is an object, or body, with only a few degrees-of-freedom, including position, and perhaps orientation in space. ... Properties For other uses, see Atom (disambiguation). ... Properties In physics, the proton (Greek proton = first) is a subatomic particle with an electric charge of one positive fundamental unit (1. ... This article or section does not cite its references or sources. ... Properties The electron is a lightweight fundamental subatomic particle that carries a negative electric charge. ...

In contrast to fermions, the gauge bosons (of which the photon is one), which mediate the four fundamental forces, are usually not considered matter, even though they have energy and some of them (W and Z bosons) also have mass. Gauge bosons are bosonic particles which act as carriers of the fundamental forces of Nature. ... In quantum physics, the photon (from Greek φως, phōs, meaning light) is the quantum of the electromagnetic field (light). ... A fundamental interaction is a mechanism by which particles interact with each other, and which cannot be explained by another more fundamental interaction. ... In physics, the W and Z bosons are the elementary particles that mediate the weak nuclear force. ...

Because matter consists of fermions, matter must be composed of quarks and leptons. There are six types of quarks (strange, charm, top, bottom, up, and down) which combine to form hadrons, primarily baryons and mesons, through the strong interaction and are actually thought to always be confined. Among the baryons are the proton and the neutron, which further combine to form the nuclei of all elements of the periodic table. Usually these nuclei are surrounded by a cloud of electrons. A nucleus with as many electrons as protons, which is thus electrically neutral, is called an atom, otherwise it is an ion. Quarks are one of the two basic constituents of matter in the Standard Model of particle physics. ... In physics, a particle is a lepton if it has a spin of 1/2 and does not experience the strong nuclear force. ... In particle physics, a hadron is a subatomic particle which experiences the strong nuclear force. ... In particle physics, the baryons are a family of subatomic particles including the proton and the neutron (collectively called nucleons), as well as a number of unstable, heavier particles (called hyperons). ... In particle physics, a meson is a strongly interacting boson, that is, it is a hadron with integral spin. ... The strong interaction or strong force is today understood to represent the interactions between quarks and gluons as detailed by the theory of quantum chromodynamics (QCD). ... Colour confinement (often just confinement) is the physics phenomenon that color charged particles (such as quarks) cannot be isolated. ... A semi-accurate depiction of the helium atom. ... A chemical element, often called simply element, is a chemical substance that cannot be decomposed or transformed into other chemical substances by ordinary chemical methods. ... The periodic table of the chemical elements is a tabular method of displaying the chemical elements, first devised in 1869 by the Russian chemist Dmitri Mendeleev. ... Properties The electron is a lightweight fundamental subatomic particle that carries a negative electric charge. ... Properties For other uses, see Atom (disambiguation). ... An ion is an atom, group of atoms, or subatomic particle that normally is electrically neutral and achieve their status as an ion by loss (and addition) of an electron. ...

In bulk, matter can exist in several different phases, according to particle density and energy density or alternatively pressure and temperature. These phases include gases, plasmas, liquids, fluids, superfluids, solids, and Bose-Einstein condensates. As conditions change, matter may change from one phase into another. These phenomena are called phase transitions, and their energetics are studied in the field of thermodynamics. In small quantities, matter can exhibit properties that are entirely different from those of bulk material. Bulk can refer to: Bulk mail Bulk Purchasing Bulk liquids Bulk material handling Bulk and Skull, a pair of characters in the Power Rangers universe. ... In the physical sciences, a phase is a set of states of a macroscopic physical system that have relatively uniform chemical composition and physical properties (i. ... Energy density is the amount of potential energy stored in a given system or region of space per unit volume or per unit mass, depending on the context. ... Pressure (symbol: p) is the force per unit area applied on a surface in a direction perpendicular to that surface. ... In thermodynamics, temperature is the physical property of a system that underlies the common notions of hot and cold —something that is hotter has the greater temperature. ... A gas is one of the four main phases of matter (after solid and liquid, and followed by plasma), that subsequently appear as a solid material is subjected to increasingly higher temperatures. ... A Plasma lamp, illustrating some of the more complex phenomena of a plasma, including filamentation A solar coronal mass ejection blasts plasma throughout the solar system. ... A liquid will assume the shape of its container. ... A subset of the phases of matter, fluids include liquids, gases, plasmas and, to some extent, plastic solids. ... Superfluidity is a phase of matter characterised by the complete absence of viscosity. ... In jewelry, a solid gold piece is the alternative to gold-filled or gold-plated jewelry. ... A Bose-Einstein condensate is a phase of matter formed by bosons cooled to temperatures very near to absolute zero. ... In physics, a phase transition, (or phase change) is the transformation of a thermodynamic system from one phase to another. ... ‹ The template below has been proposed for deletion. ...

Homogeneous matter has a definite composition and properties and any amount of it has the same composition and properties. It may be a mixture, such as brass, or elemental, like pure iron. Heterogeneous matter, such as granite, does not have a definite composition. Brass is the term used for alloys of copper and zinc in a solid solution. ... General Name, Symbol, Number iron, Fe, 26 Chemical series transition metals Group, Period, Block 8, 4, d Appearance lustrous metallic with a grayish tinge Atomic mass 55. ... Quarrying granite for the Mormon Temple, Utah Territory. ...

In chemistry, matter is often restricted to chemical substances. Only the electrons are relevant to chemical reactions and chemical properties of the material, and the nuclei determine the mass of the atoms. Other fermions are irrelevant to chemistry. Chemistry (from the Greek word χημεία (chemeia) meaning cast together or pour together) is the science of matter at the atomic to molecular scale, dealing primarily with collections of atoms (such as molecules, crystals, and metals). ... Water and steam are two different forms of the same chemical substance A chemical substance is any material with a definite chemical composition, no matter where it comes from. ... Chemical reactions are also known as chemical changes. ...

Phases

In the physical sciences, a phase is a state of a macroscopic physical system that has relatively uniform chemical composition and physical properties (i.e. density, crystal structure, index of refraction, and so forth). The most familiar examples of phases are solids, liquids, and gases. Less familiar phases include: plasmas and quark-gluon plasmas; Bose-Einstein condensates and fermionic condensates; strange matter; liquid crystals; superfluids and supersolids; and the paramagnetic and ferromagnetic phases of magnetic materials. Physical science is an encompassing term for the branches of natural science, and science (generally), that study non-living systems, in contrast to the biological sciences. ... Density (symbol: ρ - Greek: rho) is a measure of mass per unit of volume. ... Rose des Sables (Sand Rose), formed of gypsum crystals In mineralogy and crystallography, a crystal structure is a unique arrangement of atoms in a crystal. ... The refractive index (or index of refraction) of a material is the factor by which the phase velocity of electromagnetic radiation is slowed in that material, relative to its velocity in a vacuum. ... In jewelry, a solid gold piece is the alternative to gold-filled or gold-plated jewelry. ... A liquid will assume the shape of its container. ... A gas is one of the four main phases of matter (after solid and liquid, and followed by plasma), that subsequently appear as a solid material is subjected to increasingly higher temperatures. ... A Plasma lamp, illustrating some of the more complex phenomena of a plasma, including filamentation A solar coronal mass ejection blasts plasma throughout the solar system. ... A quark-gluon plasma (QGP) is a phase of quantum chromodynamics (QCD) which exists at extremely high temperature and density. ... A Bose-Einstein condensate is a phase of matter formed by bosons cooled to temperatures very near to absolute zero. ... It has been suggested that this article or section be merged with fermion condensate. ... Strange matter is an ultra-dense phase of matter that is theorized to form inside particularly massive neutron stars. ... Bold text Schlieren texture of Liquid Crystal nematic phase Liquid crystals are substances that exhibit a phase of matter that has properties between those of a conventional liquid, and those of a solid crystal. ... Superfluidity is a phase of matter characterised by the complete absence of viscosity. ... Phase diagram for 4He A supersolid is a spatially ordered superfluid. ... Simple Illustration of a paramagnetic probe made up from miniature magnets. ... Ferromagnetism is a phenomenon by which a material can exhibit a spontaneous magnetization, and is one of the strongest forms of magnetism. ... Iron filings in a magnetic field generated by a bar magnet A magnet is an object that has a magnetic field. ...

Phases are sometimes called states of matter, but this term can lead to confusion with thermodynamic states. For example, two gases maintained at different pressures are in different thermodynamic states, but the same "state of matter". ‹ The template below has been proposed for deletion. ...

Antimatter

In particle physics, 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. This gives rise to 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. Particles explode from the collision point of two relativistic (100 GeV per nucleon) gold ions in the STAR detector of the Relativistic Heavy Ion Collider. ... Please wikify (format) this article as suggested in the Guide to layout and the Manual of Style. ... Annihilation is defined as total destruction or complete obliteration of an object; having its root in the Latin nihil (nothing). ... Einstein redirects here. ... Albert Einsteins equation E=mc² is among the best-known equations of all time. ... In quantum physics, the photon (from Greek φως, phōs, meaning light) is the quantum of the electromagnetic field (light). ... This article is about electromagnetic radiation. ... The term mass in special relativity is used in a couple of different ways, occasionally leading to a great deal of confusion. ...

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 miniscule amounts, but not in enough quantity to do more than test a few of its theoretical properties. Radioactive decay is the set of various processes by which unstable atomic nuclei emit subatomic particles (radiation). ... Cosmic rays can loosely be defined as energetic particles originating outside of the Earth. ... Antihydrogen is the antimatter counterpart of hydrogen. ...

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. Science in the broadest sense refers to any knowledge or system of knowledge, attained by verifiable means. ... Science fiction is a form of speculative fiction principally dealing with the impact of imagined science and technology, or both, upon society and persons as individuals. ... Symmetry is a characteristic of geometrical shapes, equations and other objects; we say that such an object is symmetric with respect to a given operation if this operation, when applied to the object, does not appear to change it. ... To meet Wikipedias quality standards, this article or section may require cleanup. ... Baryogenesis is the generic designation for the physical processes that generate matter (more specifically, a class of fundamental particle called baryon) from an otherwise matter-empty state (such as it is generally believed to be the state of the Universe at its onset, the so-called Big Bang). ...

Dark matter

In cosmology, most models of the early universe and big bang require the existence of so called dark matter. This matter would have energy and mass, but would NOT be composed of either elementary fermions (as above) OR gauge bosons. As such, it would be composed of particles unknown to present science. Its existence is inferential at this point. // Cosmology, from the Greek: κοσμολογία (cosmologia, κόσμος (cosmos) order + λογια (logia) discourse) is the study of the Universe in its totality, and by extension, humanitys place in it. ... According to the Big Bang theory, the universe emerged from an extremely dense and hot state (bottom). ... In astrophysics, dark matter refers to matter that does not emit or reflect enough electromagnetic radiation (such as light, x-rays and so on) to be detected directly, but whose presence may be inferred from its gravitational effects on visible matter. ...

See also

• Materialism
• Particle physics (provides a historical background)

In philosophy, materialism is that form of physicalism which holds that the only thing that can truly be said to exist is matter; that fundamentally, all things are composed of material and all phenomena are the result of material interactions. ... Particles explode from the collision point of two relativistic (100 GeV per nucleon) gold ions in the STAR detector of the Relativistic Heavy Ion Collider. ...

External link

• Laycock, H., Theories of matter (essay; PDF)