State of matter
In 1925, Albert Einstein predicted a state of matter that would not be observed until 70 years later. Before that prediction, scientists already understood four forms visible in daily life: solid, liquid, gas, and plasma. A solid holds its shape because particles stay tightly packed in fixed positions. They vibrate but cannot move freely past one another. This arrangement gives solids definite volume and stable form. When heated above the melting point, a solid becomes liquid if pressure stays higher than the triple point. Liquids flow to match their container while keeping nearly constant volume. Water expands when it freezes, which is an exception among most substances. Gases expand to fill any space available to them. Their molecules travel far apart with minimal interaction forces between neighbors. Plasma differs from gases by containing charged ions and free electrons. These particles respond to electric and magnetic fields independently. Lightning creates natural plasma on Earth's surface. Stars like our Sun exist entirely as fully ionized plasma. Ninety-nine percent of ordinary matter in the universe exists as plasma.
A phase transition marks an abrupt change in properties when conditions shift. Temperature and pressure drive these structural changes across different states. Water demonstrates multiple distinct solid phases depending on temperature and pressure levels. Ice has fifteen known crystal structures existing under various environmental conditions. Iron adopts body-centred cubic structure below 912 degrees Celsius. Between 912 and 1394 degrees Celsius, iron forms face-centred cubic structure. Melting transforms solids into liquids at specific temperatures. Freezing reverses this process when heat leaves the system. Sublimation allows solids to become gases directly without becoming liquid first. Deposition lets gases turn straight into solids. Supercritical fluids appear when both temperature and pressure exceed critical values. The distinction between liquid and gas disappears above these thresholds. Supercritical carbon dioxide extracts caffeine during coffee manufacturing processes. Phase transitions define what makes one state distinct from another set of states. Superconductivity emerges through a phase transition at sharply defined transition temperatures for each material. Ferromagnetic states also demarcate boundaries via phase transitions with distinctive magnetic properties.
Glass represents a non-crystalline or amorphous solid material exhibiting glass transition when heated toward liquid state. Window glass contains silicate plus additives forming inorganic networks. Metallic alloys and ionic melts can also form glasses. Thermodynamically, glass remains metastable relative to its crystalline counterpart yet conversion rates stay practically zero. Plastic crystals maintain long-range positional order while allowing constituent molecules rotational freedom. Orientational glasses freeze that degree of freedom into quenched disordered states. Spin glasses exhibit frozen magnetic disorder within their structures. Liquid crystal states flow like liquids but display long-range order simultaneously. Para-azoxyanisole exists as nematic phase between specific temperature ranges. Rod-like molecules point in same direction within domains yet cannot rotate freely. These materials react to polarized light unlike ordinary liquids. Styrene-butadiene-styrene block copolymers undergo microphase separation creating nanometre-sized periodic structures. Chemical incompatibility prevents macroscopic demixing despite covalent bonding between blocks. Ionic liquids show similar compartmentalized layer diffusion patterns. Anions and cations appear to diffuse within micelles instead of moving freely through uniform liquid environments.
Bose-Einstein condensation occurs when bosonic particles cool close to absolute zero. A large fraction suddenly occupies the same lowest energy quantum state at specific temperatures. Helium-4 forms superfluid below lambda temperature of 2.17 Kelvin. This state possesses zero viscosity and flows without friction. Superfluid helium attempts climbing out of containers via Rollin film formation. It exhibits infinite thermal conductivity preventing any temperature gradient from forming inside. Placing a spinning container with superfluid results in quantized vortices appearing throughout. Eric Cornell and Carl Wieman produced first experimental Bose-Einstein condensate using rubidium atoms in 1995. Wolfgang Ketterle independently created one using sodium atoms that same year. Fermionic condensates compose fermions pairing together to behave like composite bosons. Pauli exclusion principle prevents individual fermions occupying identical quantum states individually. Pairs combine to form composite particles behaving as bosons then occupy same state. Superconductors display zero electrical resistivity existing only at low temperatures. Resistivity increases discontinuously to finite value sharply defined for each material. Meissner effect excludes all magnetic fields from interior perfectly. High-temperature superconductivity discovered in ceramic oxides reached temperatures up to 164 Kelvin.
Electron-degenerate matter exists inside white dwarf stars under extreme pressure conditions. Electrons remain bound yet transfer between adjacent atoms freely. Neutron-degenerate matter forms within neutron stars where vast gravitational pressure compresses atoms intensely. Inverse beta-decay forces electrons combining with protons creating superdense conglomeration of neutrons. Normally free neutrons outside atomic nuclei decay with half-life approximately ten minutes. Inside neutron stars, inverse decay overtakes normal radioactive decay processes. Cold degenerate matter also present in planets such as Jupiter and brown dwarfs. Metallic hydrogen cores expected exist even more massive brown dwarfs. More massive brown dwarfs not significantly larger due to degeneracy effects. Metals model electrons as degenerate gas moving through lattice of non-degenerate positive ions. Degenerate plasma expands little when heated because no momentum states remain available. Consequently, degenerate stars collapse into very high densities despite increasing mass. Gravitational force increases but pressure does not increase proportionally causing smaller size outcomes.
Quark-gluon plasma represents very high temperature phase where quarks become free moving independently. They travel through sea of gluons transmitting strong force binding quarks together. This state briefly attainable in extremely high-energy heavy ion collisions at particle accelerators. Scientists detected it first time in laboratory at CERN during year 2000. Unlike ordinary plasma flowing like gases, interactions within QGP make it flow like liquid. Theories predicting existence developed late 1970s and early 1980s before detection. Strange matter suspected existing inside some neutron stars close to Tolman-Oppenheimer-Volkoff limit approximately two to three solar masses. No direct evidence confirms its existence yet. Part energy manifests as strange quarks heavier analogue common down quarks. Quark-liquid nature remains unknown forming distinct color-flavor locked phase at even higher densities. Color-glass condensate describes gluonic walls traveling near speed light observed under high-energy conditions. Relativistic Heavy Ion Collider and Large Hadron Collider observe these intrinsic properties. Hagedorn temperature predicted for superstrings about ten to thirty Kelvin string theory predicts. At Planck temperature reaching ten to thirty-two Kelvin gravity becomes significant force between individual particles.
Common questions
What state of matter did Albert Einstein predict in 1925?
Albert Einstein predicted Bose-Einstein condensation as a state of matter that would not be observed until 70 years later. Scientists produced the first experimental Bose-Einstein condensate using rubidium atoms in 1995 and sodium atoms that same year.
How many forms of matter exist in daily life before plasma?
Scientists already understood four forms visible in daily life: solid, liquid, gas, and plasma. A solid holds its shape because particles stay tightly packed in fixed positions while vibrating without moving freely past one another.
When was quark-gluon plasma detected for the first time in a laboratory?
Scientists detected quark-gluon plasma for the first time in a laboratory at CERN during the year 2000. This state represents a very high temperature phase where quarks become free moving independently through a sea of gluons.
Which elements form superfluids below lambda temperature?
Helium-4 forms a superfluid below lambda temperature of 2.17 Kelvin. This state possesses zero viscosity and flows without friction while attempting to climb out of containers via Rollin film formation.
What happens to electrons inside white dwarf stars under extreme pressure conditions?
Electrons remain bound yet transfer between adjacent atoms freely within electron-degenerate matter existing inside white dwarf stars. These conditions create extremely dense environments where gravitational force increases but pressure does not increase proportionally causing smaller size outcomes.