#natural_phenomenon__naturalphenomenon all non-artificial phenomena
supertype: phenomenon any state or process known through the senses rather than by intuition or reasoning
subtype: chemical_phenomenon a natural phenomenon involving chemistry (as changes to atoms or molecules)
subtype: allotropy__allotropism the phenomenon of an element existing in two or more physical forms
subtype: exchange chemical process in which one atom or ion or group changes places with another
subtype: photochemical_exchange__photochemicalexchange an exchange produced by the chemical action of radiant energy (especially light)
subtype: crystallization__crystallizing the formation of crystals
subtype: efflorescence__bloom a powdery deposit on a surface
subtype: valency the phenomenon of forming chemical bonds
subtype: fermentation__ferment a chemical phenomenon in which an organic molecule splits into simpler substances
subtype: polymorphism.chemical_phenomenon__pleomorphism (chemistry) the existence of different kinds of crystal of the same chemical compound
subtype: dimorphism.polymorphism (chemistry) the property of certain substances that enables them to exist in two distinct crystalline forms
subtype: state_of_matter__state (chemistry) the three traditional states of matter are solids (fixed shape and volume) and liquids (fixed volume and shaped by the container) and gases (filling the container); "the solid state of water is called ice"
subtype: phase.state_of_matter__form (physical chemistry) a distinct state of matter in a system; matter that is identical in chemical composition and physical state and separated from other material by the phase boundary: "the reaction occurs in the liquid phase of the system"
subtype: dispersed_phase__dispersedphase__dispersed_particles__dispersedparticle (of colloids) a substance in the colloidal state
subtype: dispersing_phase__dispersion_medium__dispersing_medium (of colloids) a substance in which another is colloidally dispersed
subtype: liquidness__liquid__liquidity the state in which a substance exhibits a characteristic readiness to flow with little or no tendency to disperse and relatively high incompressibility
subtype: solidness__solidnes the state in which a substance has no tendency to flow under moderate stress; resists forces (such as compression) that tend to deform it; and retains an definite size and shape
subtype: gas.state_of_matter__ga the state of matter distinguished from the solid and liquid states by: relatively low density and viscosity; relatively great expansion and contraction with changes in pressure and temperature; the ability to diffuse readily; and the spontaneous tendency to become distributed uniformly throughout any container
subtype: plasma (physical chemistry) the gaseous state of hot ionized material consisting of ions and electrons and present in the stars and fusion reactors: sometimes regarded as a fourth state of matter distinct from normal gasses
subtype: geological_phenomenon a natural phenomenon involving the structure or composition of the earth
subtype: earthquake__quake__temblor__seism shaking and vibration at the surface of the earth resulting from underground movement along a fault plane of from volcanic activity
subtype: seismic_disturbance__seismicdisturbance__shock an instance of agitation of the earth's crust
subtype: earth_tremor__earthtremor__tremor__microseism a small earthquake
subtype: aftershock a tremor (or one of a series of tremors) occurring after the main shock of an earthquake
subtype: foreshock a tremor preceding an earthquake
subtype: seaquake__submarine_earthquake__submarineearthquake an earthquake at the sea bed
subtype: alluvial_fan__alluvial_cone a fan-shaped deposit where a fast flowing stream flattens out
subtype: cataclysm__catastrophe a sudden violent change in the earth's surface
subtype: continental_drift__continentaldrift the gradual movement and formation of continents (as described by plate tectonics)
subtype: sedimentation__deposit__alluviation the phenomenon of sediment or gravel accumulating
subtype: lode__load a deposit of valuable ore occurring within definite boundaries separating it from surrounding rocks
subtype: mother_lode__champion_lode the main vein of ore in a deposit
subtype: inundation__flood__deluge__alluvion the rising of a body of water and its overflowing onto normally dry land
subtype: debacle flooding caused by a tumultuous breakup of ice in a river during the spring or summer
subtype: flash_flood__flashflood a sudden local flood of great volume and short duration
subtype: floodhead a wall of water rushing ahead of the flood; "we were lucky to be safe when the floodheads hit"
subtype: frost_heave__frost_heaving upthrust of ground or pavement caused by the freezing of moist soil
subtype: volcanism the phenomena associated with volcanic activity
subtype: organic_phenomenon__organicphenomenon a natural phenomenon involving living plants and animals
subtype: abiogenesis__abiogenesi__autogenesis__autogenesi__autogeny__spontaneous_generation__spontaneousgeneration a hypothetical organic phenomenon by which living organisms are created from nonliving matter
subtype: alternation_of_generations__heterogenesis__heterogenesi__xenogenesis the alternation of two or more different forms in the life cycle of a plant or animal
subtype: metagenesis__digenesis__digenesi alternation of sexual and asexual generations
subtype: annual_ring__growth_ring an annual formation of wood in plants as they grow
subtype: bioelectricity electric phenomena in animals or plants
subtype: brainwave__brain_wave__brainwave__cortical_potential (neurophysiology) rapid fluctuations of voltage between parts of the cerebral cortex that are detectable with an electroencephalograph
subtype: alpha_rhythm__alpharhythm__alpha_wave__alphawave the normal brainwave in the electroencephalogram of a person who is awake but relaxed; occurs with a frequency of 8-12 hertz
subtype: beta_rhythm__beta_wave the normal brainwave in the encephalogram of a person who is awake and alert; occurs with a frequency between 12 and 30 hertz
subtype: delta_rhythm__deltarhythm__delta_wave__deltawave the normal brainwave in the encephalogram of a person in deep dreamless sleep; occurs with high voltage and low frequency (1 to 4 hertz)
subtype: theta_rhythm__thetarhythm__theta_wave__thetawave the normal brainwave in the encephalogram of a person who is awake but relaxed and drowsy; occurs with low frequency and low amplitude
subtype: circulation the movement of blood through the heart and blood vessels
subtype: systemic_circulation circulation that supplies blood to all the body except to the lungs
subtype: pulmonary_circulation__pulmonarycirculation circulation of blood between the heart and the lungs
subtype: vitelline_circulation__vitellinecirculation circulation of blood between the embryo and the yolk sac
subtype: cyclosis__streaming the circulation of cytoplasm within a cell
subtype: death the permanent end of all life functions in an organism or part of an organism; "the animal died a painful death"
subtype: necrobiosis__necrobiosi__cell_death (physiology) the normal degeneration and death of living cells (as in various epithelial cells)
subtype: apoptosis__apoptosi__programmed_cell_death__caspase-mediated_cell_death a type of cell death in which the cell uses specialized cellular machinery to kill itself; a cell suicide mechanism that enables metazoans to control cell number and eliminate cells that threaten the animal's survival
subtype: necrosis__mortification__gangrene__sphacelus the localized death of living cells (as from infection or the interruption of blood supply)
subtype: myonecrosis localized death of muscle cell fibers
subtype: brain_death__cerebral_death death when respiration and other reflexes are absent; consciousness is gone; organs can be removed for transplantation before the heartbeat stops
subtype: decay.organic_phenomenon__decomposition the organic phenomenon of rotting
subtype: dehiscence (biology) release of material by splitting open of an organ or tissue; (botany) natural bursting open at maturity of a fruit or other reproductive body to release seeds or spores; (surgery) bursting open of a surgically closed wound
subtype: desquamation__peeling__shedding loss of bits of outer skin by peeling or shedding or coming off in scales
subtype: exfoliation the peeling off in flakes or scales of bark or dead skin; "exfoliation is increased by sunburn"
subtype: diapedesis passage of blood cells (especially white blood cells) through intact capillary walls and into the surrounding tissue
subtype: facilitation.organic_phenomenon (neurophysiology) phenomenon that occurs when two or more neural impulses that alone are not enough to trigger a response in a neuron combine to trigger an action potential
subtype: food_chain (ecology) a community of organisms where each member is eaten in turn by another member
subtype: food_pyramid (ecology) a hierarchy of food chains with the principle predator at the top; each level preys on the level below
subtype: food_web__food_cycle (ecology) a community of organisms where there are several interrelated food chains
subtype: histocompatibility condition in which the cells of one tissue can survive in the presence of cells of another tissue; "a successful graft or translplant requires a high degree of histocompatibility"
subtype: life.organic_phenomenon the organic phenomenon that distinguishes living organisms from nonliving ones; "there is no life on the moon"
subtype: biology characteristic life processes and phenomena of living organisms: "the biology of viruses"
subtype: aerobiosis life sustained in the presence of air or oxygen
subtype: life_cycle a series of stages through which an organism passes between recurrences of a primary stage
subtype: pleomorphism (biology) the appearance of two or more distinctly different forms in the life cycle of some organisms
subtype: polymorphism (biology) the existence of two or more forms of individuals within the same animal species (independent of sex differences)
subtype: dimorphism (biology) the existence of two forms of individual within the same animal species (independent of sex differences)
subtype: rejection.organic_phenomenon (medicine) immunological response that refuses to accept substances or organisms that are recognized as foreign; "rejection of the transplanted liver"
subtype: greening__rejuvenation the phenomenon of vitality and freshness being restored; "the annual rejuvenation of the landscape"
subtype: sex-linkage an association between genes in sex chromosomes that makes some characteristics appear more frequently in one sex than in the other
subtype: physical_phenomenon a natural phenomenon involving the physics of matter and energy
subtype: atmospheric_phenomenon__atmosphericphenomenon a physical phenomenon associated with the atmosphere
subtype: cloud.atmospheric_phenomenon a visible mass of water or ice particles suspended at a considerable altitude
subtype: cirrocumulus_cloud__cirrocumulus a cloud at a high altitude consisting of a series of regularly arranged small clouds resembling ripples
subtype: cirrostratus_cloud__cirrostratus a thin uniform layer of hazy cloud at high altitude
subtype: cirrus_cloud__cirrus a wispy white cloud (usually of fine ice crystals) at a high altitude (4 to 8 miles)
subtype: mare's_tail a long narrow flowing cirrus cloud
subtype: cloud_bank__cloudbank a layer of clouds seen from a distance
subtype: contrail__condensation_trail an artificial cloud created by an aircraft; caused either by condensation due to the reduction in air pressure above the wing surface or by water vapor in the engine exhaust
subtype: cumulonimbus_cloud__cumulonimbus__thundercloud a dark cloud of great vertical extent charged with electricity; associated with thunderstorms
subtype: cumulus_cloud__cumuluscloud__cumulus__cumulu a globular cloud
subtype: altocumulus_cloud__altocumuluscloud__altocumulus__altocumulu a cumulus cloud at an intermediate altitude of 2 or 3 miles
subtype: nimbus_cloud__nimbus__rain_cloud a dark gray cloud bearing rain
subtype: storm_cloud__stormcloud a heavy dark cloud presaging rain or a storm
subtype: stratus_cloud__stratuscloud__stratus__stratu a large dark low cloud
subtype: altostratus_cloud__altostratuscloud__altostratus__altostratu a stratus cloud at an intermediate altitude of 2 or 3 miles
subtype: air_pocket__airpocket a local region of low pressure or descending air that causes a plane to lose height suddenly
subtype: aurora an atmospheric phenomenon consisting of bands of light caused by charged solar particles following the earth's magnetic lines of force
subtype: aurora_australis__southern_lights the aurora of the southern hemisphere
subtype: aurora_borealis__northern_lights the aurora of the northern hemisphere
subtype: condensate__condensation atmospheric moisture that has condensed because of cold
subtype: sweat condensation of moisture on a cold surface; "the cold glasses were streaked with sweat"
subtype: dew water that has condensed on a cool surface overnight from water vapor in the air; "in the morning the grass was wet with dew"
subtype: front.atmospheric_phenomenon (meteorology) the atmospheric phenomenon created at the boundary between two different air masses
subtype: warm_front the front of an advancing mass of warmer air
subtype: cold_front__polar_front__polarfront the front of an advancing mass of colder air
subtype: squall_line a cold front along which squalls or thunderstorms are likely
subtype: occluded_front__occlusion (meteorology) a composite front when colder air surrounds a mass of warm air and forces it aloft
subtype: greenhouse_effect warming that results when solar radiation is trapped by the atmosphere; caused by atmospheric gases that allow sunshine to pass through but absorb heat that is radiated back from the warmed surface of the earth
subtype: inversion the layer of air near the earth is cooler than an overlying layer
subtype: violent_storm__violentstorm__storm a violent weather condition with winds 64-72 knots (11 on the Beaufort scale) and precipitation and thunder and lightening
subtype: firestorm a storm in which violent winds are drawn into the column of hot air rising over a severely bombed area
subtype: storm_center__stormcenter the central area or point of lowest barometric pressure within a storm
subtype: northeaster__noreaster a storm blowing from the northeast
subtype: hailstorm a storm during which hail falls
subtype: ice_storm__icestorm__silver_storm a storm with freezing rain that leaves everything glazed with ice
subtype: rainstorm a storm with rain
subtype: line_storm__equinoctial_storm__equinoctialstorm a violent rainstorm near the time of an equinox
subtype: thundershower a short rainstorm accompanied by thunder and lightning
subtype: blizzard__snowstorm a storm with widespread snowfall accompanied by strong winds
subtype: thunderstorm__electrical_storm__electric_storm a storm resulting from strong rising air currents; heavy rain or hail along with thunder and lightning
subtype: windstorm a storm consisting of violent winds
subtype: cyclone a violent rotating windstorm
subtype: hurricane a severe tropical cyclone usually with heavy rains and winds moving a 73-136 knots (12 on the Beaufort scale)
subtype: tornado__twister a localized and violently destructive windstorm occurring over land characterized by a funnel-shaped cloud extending toward the ground
subtype: waterspout.tornado a tornado passing over water and picking up a column of water and mist
subtype: typhoon a tropical cyclone occurring in the W Pacific or Indian oceans
subtype: dust_storm__sandstorm__sirocco a windstorm that lifts up clouds of dust or sand
subtype: tempest (literary) a violent wind; "a tempest swept over the island"
subtype: whirlwind a more or less vertical column of air whirling around itself as it moves over the surface of the Earth
subtype: dust_devil a miniature whirlwind strong enough to whip dust and leaves and litter into the air
subtype: atmospheric_electricity__atmosphericelectricity electrical discharges in the atmosphere
subtype: elves__elve an acronym for Emissions of Light and Very low frequency perturbations due to Electromagnetic pulse Sources; extremely bright extremely short (less than a msec) electrical flashes forming a huge ring (up to 400 km diameter) in the ionosphere
subtype: blue_jets__jets atmospheric discharges (lasting 10 msec) bursting from the tops of giant storm clouds in blue cones that widen as they flash upward
subtype: lightning abrupt electric discharge from cloud to cloud or from cloud to earth accompanied by the emission of light
subtype: forked_lightning__chain_lightning__chainlightning a form of lightning that moves rapidly in a zigzag path with one end divided (fork-like)
subtype: bolt_of_lightning__thunderbolt__bolt a discharge of lightning accompanied by thunder
subtype: red_sprites__redsprite__sprites__sprite atmospheric electricity (lasting 10 msec) appearing as globular flashes of red (pink to blood-red) light rising to heights of 60 miles (sometimes seen together with elves)
subtype: midnight_sun the sun visible at midnight (inside the arctic or antarctic circles)
subtype: halo a circle of light around the sun or moon
subtype: solar_halo__solarhalo__parhelic_circle__parhelic_ring a luminous halo parallel to the horizon at the altitude of the sun; caused by ice crystals in the atmosphere
subtype: meteor_shower__meteor_stream a transient shower of meteors when a meteor swarm enters the earth's atmosphere
subtype: sunrise.atmospheric_phenomenon atmospheric phenomena accompanying the daily appearance of the sun
subtype: sunset.atmospheric_phenomenon atmospheric phenomena accompanying the daily disappearance of the sun
subtype: afterglow.atmospheric_phenomenon a glow sometimes seen in the sky after sunset
subtype: weather_condition__weathercondition__weather__atmospheric_condition__atmosphericcondition the meteorological conditions: temperature and wind and clouds and precipitation; "they were hoping for good weather"; "every day we have weather conditions and yesterday was no exception"
subtype: cold_weather__cold_snap__cold_wave__cold_spell a period of unusually cold weather
subtype: frost__freeze weather cold enough to cause freezing
subtype: fair_weather__sunshine__temperateness__temperatenes moderate weather; suitable for outdoor activities
subtype: hot_weather__hotweather__heat_wave__hot_spell__hotspell a period of unusually hot weather
subtype: scorcher an extremely hot day
subtype: sultriness oppressively hot and humid weather
subtype: thaw__thawing__warming warm weather following a freeze; snow and ice melt; "they welcomed the spring thaw"
subtype: precipitation__downfall the falling to earth of rain or snow or hail or sleet or mist
subtype: fine_spray precipitation in very small drops
subtype: hail precipitation of ice pellets when there are strong rising air currents
subtype: rainfall__rain water falling in drops from vapor condensed in the atmosphere
subtype: monsoon.wind any wind that changes direction with the seasons
subtype: rainstorm a storm with rain
subtype: downpour__cloudburst__deluge__waterspout__torrent__soaker a heavy rain
subtype: drizzle very light rain; stronger than mist but less than a shower
subtype: rain_shower__shower a brief period of precipitation; "the game was interrupted by a brief shower"
subtype: scattering.rain_shower__sprinkle__sprinkling a light shower that falls in some locations and not others nearby
subtype: sleet partially melted snow (or a mixture of rain and snow)
subtype: snowfall__snow precipitation falling from clouds in the form of ice crystals
subtype: snow_flurry__flurry a light brief snowfall and gust of wind (or something resembling that); "he had to close the window against the flurries"; "there was a flurry of chicken feathers"
subtype: whiteout an arctic atmospheric condition with clouds over snow produce a uniform whiteness and objects are difficult to see; occurs when the light reflected off the snow equals the light coming through the clouds
subtype: virga light wispy precipitation that evaporates before it reaches the ground (especially when the lower air is low in humidity)
subtype: elements violent or severe weather (viewed as caused by the action of the four elements); "they felt the full fury of the elements"
subtype: wind air moving (sometimes with considerable force) from an area of high pressure to an area of low pressure; "trees bent under the fierce winds"; "when there is no wind, row"
subtype: airstream a relatively well-defined prevailing wind
subtype: jet_stream__jetstream a high-speed high-altitude airstream blowing from west to east near the top of the troposphere; has important effects of the formation of weather fronts
subtype: calm_air wind moving at less than 1 knot; 0 on the Beaufort scale
subtype: zephyr__breeze__gentle_wind__air a slight wind (usually refreshing); "the breeze was cooled by the lake"; "as he waited he could feel the air on his neck"
subtype: sea_breeze__seabreeze a cooling breeze from the sea (during the daytime)
subtype: breath.zephyr a slight movement of the air; "there wasn't a breath of air in the room"
subtype: light_air__lightair wind moving 1-3 knots; 1 on the Beaufort scale
subtype: light_breeze__lightbreeze wind moving 4-7 knots; 2 on the Beaufort scale
subtype: gentle_breeze wind moving 8-12 knots; 3 on the Beaufort scale
subtype: moderate_breeze wind moving 13-18 knots; 4 on the Beaufort scale
subtype: fresh_breeze__freshbreeze wind moving 19-24 knots; 5 on the Beaufort scale
subtype: strong_breeze wind moving 25-31 knots; 6 on the Beaufort scale
subtype: chinook_wind__chinookwind__chinook__snoweater a warm dry wind blowing down the E slopes of the Rockies
subtype: harmattan a dusty wind from the Sahara that blows toward the W coast of Africa during the winter
subtype: crosswind wind blowing across the path or a ship or aircraft
subtype: fohn__foehn a warm dry wind that blows down the northern slopes of the Alps
subtype: Santa_Ana.wind__santaana a strong hot dry wind that blows in winter from the deserts of southern California toward the Pacific Coast
subtype: high_wind a very strong wind; "rain and high winds covered the region"
subtype: headwind wind blowing opposite to the path of a ship or aircraft
subtype: tailwind wind blowing in the same direction as the path of a ship or aircraft
subtype: the_doldrums__doldrums a belt of calms and light winds between the northern and southern trade winds of the Atlantic and Pacific
subtype: east_wind__easter__easterly a wind from the east
subtype: levanter an easterly wind in the western Mediterranean area
subtype: northwest_wind__northwestwind__northwester a wind from the northwest
subtype: southwester__sou'wester a strong wind from the southwest
subtype: southeaster__sou'easter a strong wind from the southeast
subtype: gale a strong wind moving 45-90 knots; force 7 to 10 on Beaufort scale
subtype: moderate_gale__near_gale wind moving 32-38 knots; 7 on the Beaufort scale
subtype: fresh_gale__freshgale wind moving 39-46 knots; 8 on the Beaufort scale
subtype: strong_gale wind moving 47-54 knots; 9 on the Beaufort scale
subtype: whole_gale__wholegale wind moving 55-63 knots; 10 on the Beaufort scale
subtype: gust__blast__blow a strong current of air; "the tree was bent almost double by the gust"
subtype: bluster.gust a violent gusty wind
subtype: sandblast a blast of wind laden with sand
subtype: puff_of_air__puff__whiff a short light gust of air
subtype: monsoon a seasonal wind in S Asia; blows from the SW (bringing rain) in summer and from the NE in winter
subtype: monsoon.wind any wind that changes direction with the seasons
subtype: north_wind__northwind__norther__boreas a wind from the north
subtype: bise__bize a dry cold north wind in SE France
subtype: mistral a strong north wind that blows in France during the winter
subtype: tramontane__tramontana a cold dry wind that blows south out of the mountains into Italy and the western Mediterranean
subtype: prevailing_wind the predominant wind direction; "the prevailing wind is from the southwest"
subtype: antitrades wind in the upper atmosphere blowing above but in the opposite direction from the trade winds
subtype: trade_wind__tradewind__trade steady winds blowing from east to west above and below the equator; "they rode the trade winds going west"
subtype: antitrade_wind__antitradewind__antitrade winds blowing from west to east and lying above the trade winds in the tropics
subtype: simoom__simoon__samiel a violent hot sand-laden wind on the deserts of Arabia and North Africa
subtype: south_wind__southwind__souther__southerly a wind from the south
subtype: squall sudden violent winds; often accompanied by precipitation
subtype: line_squall a squall advancing along a front that forms a definite line
subtype: air_current__aircurrent__draft__draught a current of air (usually coming into a room or vehicle)
subtype: thermal rising current of warm air
subtype: updraft an strong upward air current
subtype: downdraft a strong downward air current
subtype: west_wind__wester wind that blows from west to east
subtype: prevailing_westerly__westerly the west-to-east winds that occur in the temperate zones of the Earth
subtype: atmospheric_state__atmosphericstate__atmosphere the weather or climate at some place; "the atmosphere was thick with fog"
subtype: air_mass a large body of air with uniform characteristics horizontally
subtype: high_pressure__high an air mass of higher than normal pressure; "the east coast benefits from a Bermuda high"
subtype: low_pressure__lowpressure__low__depression an air mass of lower pressure; often brings precipitation; "a low moved in over night bringing sleet and snow"
subtype: anticyclone (meteorology) winds spiraling outward from a high-pressure center; circling clockwise in the northern hemisphere and counter-clockwise in the southern
subtype: cyclone.atmospheric_state (meteorology) rapid inward circulation of air masses about a low-pressure center; circling counterclockwise in the northern hemisphere and clockwise in the southern
subtype: fogginess__foggines__murk__murkiness an atmosphere in which visibility is reduced because of a cloud of some substance
subtype: fug (British informal) an airless smoky smelly atmosphere
subtype: good_weather weather suitable for outdoor activities
subtype: calmness.good_weather an absence of strong winds or rain
subtype: stillness__stillnes__windlessnes calmness without winds
subtype: lull__quiet a period of calm weather; "there was a lull in the storm"
subtype: mildness__clemency good weather with comfortable temperatures
subtype: bad_weather__inclemency__inclementness__inclementnes weather unsuitable for outdoor activities
subtype: raw_weather__rawweather unpleasantly cold and damp weather
subtype: storminess the state of being stormy; "he dreaded the storminess of the North Atlantic in winter"
subtype: boisterousness.storminess a turbulent and stormy state of the sea
subtype: windiness__windines__breezines a mildly windy state of the air
subtype: tempestuousness__tempestuousnes a state of wild storminess
subtype: choppiness__roughness__roughnes__roughwater used of the sea
subtype: cloud_cover__cloudcover__cloudiness__overcast the state of the sky when it is covered by clouds
subtype: turbulence instability in the atmosphere
subtype: clear-air_turbulence__clearairturbulence strong turbulence in an otherwise cloudless region that subjects aircraft to violent updrafts or downdrafts
subtype: boundary_layer the layer of slower flow of a fluid past a surface
subtype: chaos__chao the formless and disordered state of matter before the creation of the cosmos
subtype: decalescence phenomenon that occurs when a metal is being heated and there is a sudden slowing in the rate of temperature increase; slowing is caused by a change in the internal crystal structure of the metal
subtype: electrical_phenomenon a physical phenomenon involving electricity
subtype: amperage the strength of a electrical current measured in amperes
subtype: capacitance__electrical_capacity__capacity an electrical phenomenon whereby an electric charge is stored
subtype: electrical_elastance__elastance the reciprocal of capacitance
subtype: electric_charge__charge the quantity of unbalanced electricity in a body (either positive or negative) and construed as an excess or deficiency of electrons; "the battery needed a fresh charge"
subtype: electrostatic_charge__electrostaticcharge the electric charge at rest on the surface of an insulated body (which establishes and adjacent electrostatic field)
subtype: positive_charge having a deficiency of electrons; having a higher electric potential
subtype: negative_charge having a surplus of electrons; having a lower electric potential
subtype: pyroelectricity generation of an electric charge on certain crystals (such as tourmaline) as a result of a change in temperature
subtype: electric_current__current a flow of electricity through a conductor; "the current was measured in amperes"
subtype: thermionic_current an electric current produced between two electrodes as a result of electrons emitted by thermionic emission
subtype: dielectric_heating heating of an insulator by a high-frequency electric field
subtype: induction.electrical_phenomenon an electrical phenomenon whereby an electromotive force (EMF) is generated in a closed circuit by a change in the flow of current
subtype: electromagnetic_mutual_induction__mutual_induction generation of electromotive forces in each other by two adjacent circuits
subtype: self-induction generation of an electromotive force (EMF) in a circuit by changing the current in that circuit; usually measured in henries
subtype: electric_potential__potential__potential_difference__potentialdifference__potential_drop__potentialdrop__voltage the difference in electrical charge between two points in a circuit expressed in volts
subtype: evoked_potential the electrical response of the central nervous system produced by an external stimulus; "he measured evoked potentials with an electroencephalogram"
subtype: resting_potential__restingpotential the potential difference between the two sides of the membrane of a nerve cell when the cell is not conducting an impulse
subtype: conductance a material's capacity to conduct electricity; measured as the reciprocal of electrical resistance
subtype: electric_resistance__electrical_resistance__impedance__resistance__resistivity__ohmic_resistance__ohmicresistance a material's opposition to the flow of electric current; measured in ohms
subtype: ohmage the ohmic resistance of a conductor
subtype: reactance opposition to the flow of electric current resulting from inductance and capacitance (rather than resistance)
subtype: reluctance (physics) opposition to magnetic flux (analogous to electric resistance)
subtype: skin_effect the tendency of high-frequency alternating current to distribute near the surface of a conductor
subtype: electrical_disturbance electrical signals produced by unwanted sources (atmospherics or receiver noise or unwanted transmitters)
subtype: voltage__electromotiveforce__emf the rate at which energy is drawn from a source that produces a flow of electricity in a circuit; expressed in volts
subtype: electricity a physical phenomenon associated with stationary or moving electrons and protons
subtype: galvanism electricity produced by chemical action
subtype: hydroelectricity electricity produced by water power
subtype: piezoelectricity__piezoelectric_effect__piezoelectriceffect__piezo_effect__piezoeffect electricity produced by mechanical pressure on certain crystals (notably quartz or Rochelle salt); alternatively, electrostatic stress produces a change in the linear dimensions of the crystal
subtype: static_electricity electricity produced by friction
subtype: dynamic_electricity__dynamicelectricity__current_electricity__currentelectricity a flow of electric charge
subtype: thermoelectricity electricity produced by heat (as in a thermocouple)
subtype: energy (physics) the capacity of a physical system to do work; the units of energy are joules or ergs; "energy can take a wide variety of forms"
subtype: activation_energy the energy that an atomic system must acquire before a process (such as an emission or reaction) can occur
subtype: alternative_energy__alternativeenergy energy derived from sources that do not use up natural resources or harm the environment
subtype: solar_energy__solarenergy__solar_power__solarpower energy from the sun that is converted into thermal or electrical energy; "the amount of energy falling on the earth is given by the solar constant, but very little use has been made of solar energy"
subtype: wind_generation__wind_power power derived from the wind (as by windmills)
subtype: atomic_energy__nuclear_energy__nuclearenergy the energy released by a nuclear reaction
subtype: atomic_power__nuclear_power__nuclearpower nuclear energy regarded as a source of electricity for the power grid (for civilian use)
subtype: binding_energy__bindingenergy__separation_energy the energy required to separate particles from a molecule or atom or nucleus; equals the mass defect
subtype: chemical_energy__chemicalenergy that part of the energy in a substance that can be released by a chemical reaction
subtype: electrical_energy__electricity energy made available by the flow of electric charge through a conductor; "they built a car that runs on electricity"
subtype: alternating_current__alternatingcurrent__AC an electric current that reverses direction sinusoidally; "In the US most household current is AC at 60 cycles per second"
subtype: direct_current__DC an electric current that flows in one direction steadily
subtype: signal.electrical_energy an electric quantity (voltage or current or field strength) whose modulation represents coded information about the source from which it comes
subtype: energy_level__energy_state a definite stable energy that a physical system can have; used especially of the state of electrons in atoms or molecules; "according to quantum theory only certain energy levels are possible"
subtype: rest_energy the energy equivalent to the mass of a particle at rest in an inertial frame of reference; equal to the rest mass times the square of the speed of light
subtype: work.energy (physics) a manifestation of energy; the transfer of energy from one physical system to another expressed as the product of a force and the distance through which it moves a body in the direction of that force; "work equals force times distance"
subtype: heat_energy__heat a form of energy that is transferred by a difference in temperature
subtype: heat_of_dissociation the heat required for a fluid substance to break up into simpler constituents
subtype: heat_of_formation the heat evolved or absorbed during the formation of one mole of a substance from its component elements
subtype: heat_of_solution the heat evolved or absorbed when one mole of a substance is dissolved in a large volume of a solvent
subtype: latent_heat__heat_of_transformation heat absorbed or radiated during a change of phase at a constant temperature and pressure
subtype: heat_of_condensation heat liberated by a unit mass of gas at its boiling point as it condenses into a liquid; "the heat of condensation is equal to the heat of vaporization"
subtype: heat_of_fusion heat absorbed by a unit mass of a solid at its melting point in order to convert the solid into a liquid at the same temperature; "the heat of fusion is equal to the heat of solidification"
subtype: heat_of_solidification heat liberated by a unit mass of liquid at its freezing point when it solidifies
subtype: heat_of_sublimation heat absorbed by a unit mass of material when it changes from a solid to a gaseous state
subtype: heat_of_vaporization__heat_of_vaporisation heat absorbed by a unit mass of a material at its boiling point in order to convert the material into a gas at the same temperature
subtype: specific_heat the heat required to raise the temperature of one gram of a substance one degree centigrade
subtype: mechanical_energy energy in a mechanical form
subtype: kinetic_energy__kineticenergy__K.E. the mechanical energy that a body has by virtue of its motion
subtype: potential_energy__potentialenergy__P.E. the mechanical energy that a body has by virtue of its position; stored energy
subtype: elastic_energy__elasticenergy__elastic_potential_energy__elasticpotentialenergy potential energy that is stored when a body is deformed (as in a coiled spring)
subtype: radiant_energy__radiantenergy energy that is transmitted in the form of (electromagnetic) radiation; energy that exists in the absence of matter
subtype: luminous_energy the energy associated with visible light
subtype: power (physics) the rate of doing work; measured in watts (= joules/second)
subtype: electrical_power__electric_power__wattage the product of voltage and current
subtype: load.electrical_power the power output of a generator or power plant
subtype: waterpower the power to do work that is latent in a head of water
subtype: ectropy the opposite of entropy: increasing order (as resulting from growth and development)
subtype: entropy (thermodynamics) a measure of the amount of energy in a system that is available for doing work; entropy increases as matter and energy in the universe degrade to an ultimate state of inert uniformity
subtype: conformational_entropy entropy calculated from the probability that a state could be reached by chance alone
subtype: event.physical_phenomenon (relativity theory) a phenomenon located at a single point in space-time; the fundamental observational entity in relativity theory
subtype: field_of_force__field__force_field__forcefield the space around a radiating body within which its electromagnetic oscillations can exert force on another similar body not in contact with it
subtype: electric_field a field of force surrounding a charged particle
subtype: electrostatic_field__electrostaticfield electric field associated with static electric charges
subtype: gravitational_field__gravitationalfield a field of force surrounding a body of finite mass
subtype: magnetic_field__magnetic_flux__flux the lines of force surrounding a permanent magnet or a moving charged particle
subtype: magnetosphere the magnetic field of a planet; the volume around the planet in which charged particles are subject more to the planet's magnetic field than to the solar magnetic field
subtype: solar_magnetic_field the magnetic field of the sun
subtype: radiation_field__radiationfield a field that represents the energy lost from the radiator to space
subtype: force the physical influence that produces a change in a physical quantity; "force equals mass times acceleration"
subtype: aerodynamic_force__aerodynamicforce forces acting on airfoils in motion relative to the air (or other gaseous fluids)
subtype: aerodynamic_lift__aerodynamiclift__lift the component of the aerodynamic forces acting on an airfoil that opposes gravity
subtype: ground_effect apparent increase in aerodynamic lift experienced by an aircraft flying close to the ground
subtype: chemical_attraction__affinity the force attracting atoms to each other and binding them together in a molecule: "basic dyes have an affinity for wool and silk"
subtype: attractive_force__attraction the force by which one object attracts another
subtype: affinity (immunology) the attraction between an antigen and an antibody
subtype: chemical_bond__bond an electrical force linking atoms
subtype: covalent_bond a chemical bond that involves sharing a pair of electrons between atoms in a molecule
subtype: coordinate_bond__dative_bond a covalent bond in which both electrons are provided by one of the atoms
subtype: cross-link__crosslink__crosslinkage a side bond that links two adjacent chains of atoms in a complex molecule
subtype: hydrogen_bond a chemical bond consisting of a hydrogen atom between two electronegative atoms (e.g., oxygen or nitrogen) with one side be a covalent bond and the other being an ionic bond
subtype: ionic_bond__ionicbond__electrovalent_bond__electrovalentbond__electrostatic_bond__electrostaticbond a chemical bond in which one atom loses an electron to form a positive ion and the other atom gains to electron to form a negative ion
subtype: metallic_bond a chemical bond in which electrons are shared over many nuclei and electronic conduction occurs
subtype: peptide_bond__peptidebond__peptide_linkage__peptidelinkage the primary linkage of all protein structures; the chemical bond between the carboxyl groups and amino groups that unites a peptide
subtype: gravity__gravitation__gravitational_attraction__gravitationalattraction__gravitational_force__gravitationalforce the force of attraction between all masses in the universe; especially the attraction of the earth's mass for bodies near its surface; "gravitation cannot be held responsible for people falling in love"--Albert Einstein
subtype: solar_gravity__solargravity the gravity of the sun; "solar gravity creates extreme pressures and temperatures"
subtype: magnetism__magnetic_attraction__magnetic_force attraction for iron; associated with electric currents as well as magnets; characterized by fields of force
subtype: electromagnetism magnetism produced by an electric current; "electromagnetism was discovered when it was observed that a copper wire carrying an electric current can magnetize pieces of iron or steel near it"
subtype: antiferromagnetism magnetic field creates parallel but opposing spins; varies with temperature
subtype: ferrimagnetism a phenomenon in ferrites where there can be incomplete cancellation of antiferromagnetic arranged spins giving a net magnetic moment
subtype: diamagnetism phenomenon exhibited by materials like copper or bismuth that become magnetized in a magnetic field with a polarity opposite to the magnetic force; unlike iron they are slightly repelled by a magnet
subtype: ferromagnetism phenomenon exhibited by materials like iron (nickel or cobalt) that become magnetized in a magnetic field and retain their magnetism when the field is removed
subtype: paramagnetism materials like aluminum or platinum become magnetized in a magnetic field but it disappears when the field is removed
subtype: van_der_Waal's_forces relatively weak attraction between neutral atoms and molecules arising from polarization induced in each particle by the presence of other particles
subtype: repulsive_force__repulsiveforce__repulsion the force by which bodies repel one another
subtype: centrifugal_force__centrifugalforce the outward force on a body moving in a curved path around another body
subtype: centripetal_force__centripetalforce the inward force on a body moving in a curved path around another body
subtype: cohesion (physics) the intermolecular force that holds together the molecules in a solid or liquid
subtype: Coriolis_force a force due to the earth's rotation; acts on a body in motion (airplane or projectile) in a rotating reference frame; in a rotating frame of reference Newton's second law of motion can be made to apply if in addition to the real forces acting on a body a Coriolis force and a centrifugal force are introduced
subtype: impetus__impetu__drift__impulsion a force that moves something along
subtype: Lorentz_force the force experienced by a point charge moving along a wire that is in a magnetic field; the force is at right angles to both the current and the magnetic field; "the Lorentz force can be used to suspend a current-carrying object between two magnets"
subtype: moment.force the moment of a couple is the product of its force and the distance between its opposing forces
subtype: dipole_moment the moment of a dipole
subtype: electric_dipole_moment the dipole moment in an electric dipole
subtype: magnetic_dipole_moment (physics) a current loop gives rise to a magnetic field characteristic of a magnetic dipole; "An orbiting electron in an atom will have a magnetic dipole moment"
subtype: propulsion a propelling force
subtype: nuclear_propulsion__nuclearpropulsion the use of a nuclear reactor either to produce electricity to power an engine (as in a nuclear submarine) or to directly heat a propellant (as in nuclear rockets)
subtype: reaction_propulsion propulsion that results from the ejection at high velocity of a mass of gas to which the vehicle reacts with an equal and opposite momentum
subtype: jet_propulsion__jetpropulsion propulsion by means of the discharge of a jet of fluid toward the rear
subtype: rocket_propulsion reaction propulsion using stored oxygen for combustion; used where there is insufficient atmospheric oxygen
subtype: pull.force the force used in pulling; "the pull of the moon"; "the pull of the current"
subtype: push.force__thrust the force used in pushing; "the push of the water on the walls of the tank"; "the thrust of the jet engines"
subtype: reaction.force (mechanics) the equal and opposite force that is produced when any force is applied to a body; "every action has an equal and opposite reaction"
subtype: stress (physics) force that produces strain on a physical body
subtype: tension.stress (physics) a stress that produces an elongation of an elastic physical body; "the direction of maximum tension moves asymptotically toward the direction of the shear"
subtype: breaking_point the degree of tension or stress at which something breaks
subtype: torsion__torque a twisting force
subtype: magnetic_moment__moment_of_a_magnet the torque exerted on a magnet or dipole when it is placed in a magnetic field
subtype: magnetomotive_force the force that produces magnetic flux
subtype: life_force__vital_force__vitalforce__vitality__elan_vital (biology) a hypothetical force (not physical or chemical) once thought by Henri Bergson to cause the evolution and development of organisms
subtype: hysteresis the lagging of an effect behind its cause; especially the phenomenon in which the magnetic induction of a ferromagnetic material lags behind the changing magnetic field
subtype: resonance an excited state of a stable particle causing a sharp maximum in the probability of absorption of electromagnetic radiation
subtype: nuclear_resonance__nuclearresonance the resonance absorption of a gamma ray by a nucleus identical to the nucleus that emitted the gamma ray
subtype: magnetic_resonance resonance of electrons or atoms or molecules or nuclei to radiation frequencies as a result of space quantization in a magnetic field
subtype: nuclear_magnetic_resonance__NMR__proton_magnetic_resonance resonance of protons to radiation in a magnetic field
subtype: mechanical_phenomenon a physical phenomenon associated with the equilibrium or motion of objects
subtype: inertia (physics) the tendency of a body to maintain is state of rest or uniform motion unless acted upon by an external force
subtype: moment_of_inertia the tendency of a body to resist angular acceleration
subtype: leverage.mechanical_phenomenon__purchase the mechanical advantage gained by being in a position to use a lever
subtype: sound.mechanical_phenomenon mechanical vibrations transmitted by an elastic medium; "falling trees make a sound in the forest even when no one is there to hear them"
subtype: ultrasound very high frequency sound; used in ultrasonography
subtype: sound_unit__soundunit any acoustic unit of measurement
subtype: bel__B a logarithmic unit of sound intensity equal to 10 decibels
subtype: decibel__dB__db__db a logarithmic unit of sound intensity; 10 times the logarithm of the ratio of the sound intensity to some reference intensity
subtype: sone a unit of perceived loudness equal to the loudness of a 1000-hertz tone at 40 dB above threshold
subtype: phon a unit of subjective loudness
subtype: trajectory__flight the path followed by an object moving through space
subtype: ballistic_trajectory__ballistictrajectory__ballistics the trajectory of an object in free flight
subtype: gravity-assist__gravityassist (spaceflight) a trajectory that passes close to a planetary body in order to gain energy from its gravitational field
subtype: resistance.mechanical_phenomenon any mechanical force that tends to retard or oppose motion
subtype: friction__rubbing the resistance encountered when one body is moved in contact with another
subtype: abrasion__grinding__attrition__detrition the wearing down of rock particles by friction due to water or wind or ice
subtype: adhesive_friction__grip__traction the friction between a body and the surface on which it moves (as between an automobile tire and the road)
subtype: acoustic_resistance__acoustic_impedance__acoustic_reactance opposition to the flow of sound through a surface; acoustic resistance is the real component of acoustic impedance and acoustic reactance is the imaginary component
subtype: retarding_force__retardingforce__drag the phenomenon of resistance to motion through a fluid
subtype: sonic_barrier__sonicbarrier__sound_barrier__soundbarrier the increase in aerodynamic drag as an airplane approaches the speed of sound
subtype: windage.retarding_force the retarding force of air friction on a moving object
subtype: opacity the phenomenon of not permitting the passage of electromagnetic radiation
subtype: optical_opacity__opticalopacity opacity to light
subtype: radiopacity__radio-opacity__radioopacity opacity to X-rays or other radiation
subtype: optical_phenomenon__opticalphenomenon a physical phenomenon related to or involving light
subtype: optical_aberration__opticalaberration__aberration__distortion an optical phenomenon resulting from the failure of a lens or mirror to produce a good image
subtype: chromatic_aberration__chromaticaberration an optical aberration in which the image has colored fringes
subtype: spherical_aberration__sphericalaberration a optical aberration resulting in a distorted image
subtype: absorption_band a dark band in the spectrum of white light that has been transmitted through a substance that exhibits absorption at selective wavelengths
subtype: diffraction when light passes sharp edges or goes through narrow slits the rays are deflected and produce fringes of light and dark bands
subtype: X-ray_diffraction the scattering of X rays by the atoms of a crystal; the diffraction pattern shows structure of the crystal
subtype: incidence the striking of a light beam on a surface; "he measured the angle of incidence of the reflected light"
subtype: optical_illusion__opticalillusion an optical phenomenon that results in a false or deceptive visual impression
subtype: apparent_motion__motion__apparent_movement__movement an optical illusion of motion produced by viewing a rapid succession of still pictures of a moving object; "the cinema relies on apparent motion"; "the succession of flashing lights gave an illusion of movement"
subtype: mirage.optical_illusion an optical illusion in which atmospheric refraction by a layer of hot air distorts or inverts reflections of distant objects
subtype: fata_morgana a mirage in the Strait of Messina (attributed to the Arthurian sorcerer Morgan le Fay)
subtype: pleochroism the phenomenon of different colors appearing when certain crystals are viewed from different directions
subtype: dichroism pleochroism of a crystal so that it exhibits two different colors when viewed from two different directions
subtype: trichroism pleochroism of a crystal so that it exhibits three different colors when viewed from three different directions
subtype: polarization__polarisation the phenomenon in which waves of light or other radiation are restricted in direction of vibration
subtype: parallax the apparent displacement of an object as seen from two different points that are not on a line with the object
subtype: heliocentric_parallax__annual_parallax the parallax of a celestial body using two points in the earth's orbit around the sun as the baseline
subtype: stellar_parallax__stellarparallax the heliocentric parallax of a star
subtype: geocentric_parallax__diurnal_parallax__diurnalparallax the parallax of a celestial body using two points on the surface of the earth as the earth rotates
subtype: horizontal_parallax the maximum parallax observed when the celestial body is at the horizon
subtype: solar_parallax__solarparallax the angle subtended by the mean equatorial radius of the Earth at a distance of one astronomical unit
subtype: Tyndall_effect the phenomenon in which light is scattered by very small particles in its path; it makes a beam of light visible; the scattered light is mainly blue
subtype: pressure_level__pressure__force_per_unit_area the force applied to a unit area of surface; measured in pascals (SI unit) or in dynes (cgs unit); "the compressed gas exerts an increased pressure"
subtype: blood_pressure__bloodpressure the pressure of the circulating blood against the walls of the blood vessels; results from the systole of the left ventricle of the heart; sometimes measured for a quick evaluation of a person's health; "adult blood pressure is considered normal at 120/80 where the first number is the systolic pressure and the second is the diastolic pressure"
subtype: systolic_pressure the blood pressure (as measured by a sphygmomanometer) during the contraction of the left ventricle of the heart
subtype: diastolic_pressure__diastolicpressure the blood pressure (as measured by a sphygmomanometer) after the contraction of the heart while the chambers of the heart refill with blood
subtype: arterial_pressure the pressure of the circulating blood on the arteries; "arterial pressure is the product of cardiac output and vascular resistance"
subtype: venous_pressure the pressure exerted on the walls of the veins by the circulating blood
subtype: gas_pressure__gaspressure the pressure exerted by a gas
subtype: atmospheric_pressure__atmosphericpressure__air_pressure__airpressure the pressure exerted by the atmosphere
subtype: compartment_pressure__compartmentpressure the air pressure maintained in the air-tight compartment of an aircraft
subtype: barometric_pressure atmospheric pressure as indicated by a barometer
subtype: head.pressure_level the pressure exerted by a fluid; "a head of steam"
subtype: hydrostatic_head__hydrostatichead the pressure at a given point in a liquid measured in terms of the vertical height of a column of the liquid needed to produce the same pressure
subtype: intraocular_pressure__intraocularpressure pressure inside the eyeball;regulated by resistance to the outward flow of aqueous humor; "glaucoma results from increased intraocular pressure"
subtype: oil_pressure__oilpressure pressure that keeps oil on the moving parts of an internal-combustion engine
subtype: osmotic_pressure__osmoticpressure (physical chemistry) the pressure exerted by a solution necessary to prevent osmosis into that solution when it is separated from the pure solvent by a semipermeable membrane
subtype: corpuscular-radiation_pressure__corpuscularradiationpressure__radiation_pressure__radiationpressure the minute pressure exerted on a surface normal to the direction of propagation of a wave
subtype: acoustic_radiation_pressure (acoustics) the pressure exerted on a surface normal to the direction of propagation of a sound wave
subtype: instantaneous_sound_pressure__instantaneoussoundpressure__sound_pressure__soundpressure the difference between the instantaneous pressure at a point in a sound field and the average pressure at that point
subtype: suction a force over an area produced by a pressure difference
subtype: vapor_pressure__vaporpressure__vapour_pressure the pressure exerted by a vapor; often understood to mean saturated vapor pressure (the vapor pressure of a vapor in contact with its liquid form)
subtype: radiation the physical phenomenon of radiating energy in the form of waves or particles
subtype: ionizing_radiation high-energy radiation capable of producing ionization in substances through which it passes
subtype: alpha_radiation__alpha_ray__alpharay the radiation of alpha particles during radioactive decay
subtype: beta_radiation__beta_ray__electron_radiation radiation of beta particles during radioactive decay
subtype: cosmic_ray highly penetrating ionizing radiation of extraterrestrial origin; consisting chiefly of protons and alpha particles; collision with atmospheric particles results in rays and particles of many kinds
subtype: neutron_radiation__neutronradiation radiation of neutrons (as by a neutron bomb)
subtype: X_ray__X-radiation__roentgen_ray electromagnetic radiation of short wavelength produced when high-speed electrons strike a solid target
subtype: electromagnetic_radiation__electromagneticradiation__electromagnetic_wave__electromagneticwave__nonparticulate_radiation radiation consisting of waves of energy associated with electric and magnetic fields resulting from the acceleration of an electric charge
subtype: actinic_radiation__actinic_ray__actinicray electromagnetic radiation that can produce photochemical reactions
subtype: infrared_radiation__infrared__infrared_light__infrared_emission electromagnetic radiation with wavelengths longer than visible light but shorter than radio waves
subtype: visible_light__visiblelight__light__visible_radiation__visibleradiation (physics) electromagnetic radiation that can produce a visual sensation; "the light was filtered through a soft glass window"
subtype: beam_of_light__beam__light_beam__lightbeam__ray__rayoflight__shaft__shaft_of_light a column of light (as from a beacon)
subtype: heat_ray a ray that produces a thermal effect
subtype: infrared_ray a ray of infrared radiation; produces a thermal effect (as from an infrared lamp)
subtype: high_beam the beam of a car's headlights that provides distant illumination
subtype: moonbeam__moonray a ray of moonlight
subtype: sunbeam__sunray a ray of sunlight
subtype: laser_beam__laserbeam a beam of light generated by a laser
subtype: low_beam__lowbeam the beam of a car's headlights that provides illumination for a short distance
subtype: candlelight__candle_flame the light provided by a burning candle
subtype: corona.visible_light one or more circles of light seen around a luminous object
subtype: counterglow__gegenschein a faint spot of light in the night sky that appears directly opposite the position of the sun; a reflection of sunlight by micrometeoric material in space
subtype: daylight light during the daytime
subtype: firelight the light of a fire (especially in a fireplace)
subtype: fluorescence light emitted during absorption of radiation of some other (invisible) wavelength
subtype: autofluorescence self-induced fluorescence
subtype: phosphorescence a fluorescence that persists after the bombarding radiation has ceased
subtype: friar's_lantern__ignis_fatuus__jack-o'-lantern__will-o'-the-wisp a pale light sometimes seen at night over marshy ground
subtype: gaslight light yielded by the combustion of illuminating gas
subtype: glowing__radiance__glow the amount of electromagnetic radiation leaving or arriving at a point on a surface
subtype: aureole__corona the outermost region of the sun's atmosphere; visible as a white halo during a solar eclipse
subtype: half-light a grayish light (as at dawn or dusk or in dim interiors)
subtype: incandescence.visible_light__glow the phenomenon of light emission by a body as its temperature is raised
subtype: lamplight light from a lamp
subtype: luminescence light not due to incandescence; occurs at low temperatures
subtype: bioluminescence luminescence produced by physiological processes (as in the firefly)
subtype: chemiluminescence luminescence resulting from a chemical reaction as the oxidation of luciferin in fireflies
subtype: meteor__shooting_star a streak of light in the sky at night that results when a meteoroid hits the earth's atmosphere and air friction causes the meteoroid to melt or vaporize or explode
subtype: bolide__fireball an especially luminous meteor (sometimes exploding)
subtype: moonlight__moonshine__moon the light of the moon; "moonlight is the smuggler's enemy"; "the moon was bright enough to read by"
subtype: starlight the light of the stars
subtype: sunlight__sunshine__sun the rays of the sun; "the shingles were weathered by the sun and wind"
subtype: streamer light that streams; "streamers of flames"
subtype: torchlight light from a torch or torches
subtype: twilight the diffused light from the sky when the sun is below the horizon but its rays are refracted by the atmosphere of the earth
subtype: ultraviolet_illumination__ultravioletillumination__ultraviolet__ultraviolet_radiation__ultravioletradiation__ultraviolet_light__ultravioletlight__UV radiation lying in the ultraviolet range; wave lengths shorter than light but longer than X rays
subtype: electron_beam__beam__ray a group of nearly parallel lines of electromagnetic radiation
subtype: cathode_ray__cathoderay a beam of electrons emitted by the cathode of an electrical discharge tube
subtype: particle_beam a collimated flow of particles (atoms or electrons or molecules)
subtype: ion_beam__ionbeam__inoic_beam__inoicbeam a beam of ions moving in the same direction at the same speed
subtype: black-body_radiation__blackbody_radiation__blackbodyradiation the electromagnetic radiation that would be radiated from an ideal black body; the distribution of energy in the radiated spectrum of a black body depends only on temperature and is determined by Planck's radiation law
subtype: Hertzian_wave an electromagnetic wave generated by oscillations in an electric circuit
subtype: gamma_radiation__gammaradiation__gamma_ray__gammaray electromagnetic radiation emitted during radioactive decay and having an extremely short wavelength
subtype: line.electromagnetic_radiation a single frequency (or very narrow band) of radiation in a spectrum
subtype: microwave a short electromagnetic wave (longer than infrared but shorter than radio waves); used for radar and microwave ovens
subtype: radio_wave__radiowave__radio_emission__radioemission__radio_radiation__radioradiation an electromagnetic wave with a wavelength between 0.5 cm to 30,000 m
subtype: sky_wave__skywave a radio wave that is reflected back to earth by the ionosphere or a communications satellite; permits transmission around the curve of the earth's surface
subtype: ionospheric_wave__ionosphericwave a sky wave that is reflected by the ionosphere
subtype: ground_wave a radio wave propagated on or near the earth's surface
subtype: radio_signal__radiosignal a radio wave used to transmit and receive messages
subtype: carrier_wave__carrierwave__carrier a radio wave that can be modulated in order to transmit a signal
subtype: short_wave__shortwave a radio wave with a wavelength less than 100 meters
subtype: long_wave a radio wave with a frequency less than 300 kilohertz
subtype: X_ray__X-radiation__roentgen_ray electromagnetic radiation of short wavelength produced when high-speed electrons strike a solid target
subtype: corpuscular_radiation__corpuscularradiation__particulate_radiation__particulateradiation a stream of atomic or subatomic particles that may be charged positively (e.g. alpha particles) or negatively (e.g. beta particles) or not at all (e.g. neutrons)
subtype: alpha_radiation__alpha_ray__alpharay the radiation of alpha particles during radioactive decay
subtype: beta_radiation__beta_ray__electron_radiation radiation of beta particles during radioactive decay
subtype: neutron_radiation__neutronradiation radiation of neutrons (as by a neutron bomb)
subtype: radioactivity__activity radiation resulting from radioactive decay
subtype: solar_radiation__solarradiation radiation from the sun
subtype: solar_flare__solarflare__flare a sudden eruption of intense high-energy radiation from the sun's surface; associated with sunspots and radio interference
subtype: solar_prominence__solarprominence large eruptions of luminous hydrogen gas that rise thousands of kilometers above the chromosphere
subtype: solar_wind__solarwind a stream of protons moving radially from the sun
subtype: radiation.action the act of radiating
subtype: bombardment the act (or an instance) of subjecting a body or substance to the impact of high-energy particles (as electrons or alpha rays)
subtype: reflection.physical_phenomenon__reflexion the phenomenon of a propagating wave (light or sound) being thrown back from a surface
subtype: virtual_image__virtualimage a reflected optical image (as seen in a plane mirror)
subtype: zodiacal_light a luminous tract in the sky; a reflection of sunlight from cosmic dust in the plane of the ecliptic; visible just before sunrise and just after sunset
subtype: refraction the change in direction of a propagating wave (light or sound) when passing from one medium to another
subtype: double_refraction__birefringence splitting a ray into two parallel rays polarized perpendicularly
subtype: resolving_power__resolvingpower__resolution the ability of a microscope or telescope to measure the angular separation of images that are close together
subtype: resolution.physical_phenomenon (computer science) the number of pixels per square inch on a computer-generated display; the greater the resolution, the better the picture
subtype: conduction__conductivity the transmission of heat or electricity or sound
subtype: electrical_conduction the passage of electricity through a conductor
subtype: photoconductivity__photoconduction change in the electrical conductivity of a substance as a result of absorbing electromagnetic radiation
subtype: superconductivity the disappearance of electrical resistance at very low temperatures
subtype: electric_discharge__discharge__spark__arc__electric_arc electrical conduction through a gas in an applied electric field
subtype: brush_discharge discharge between electrodes creating visible streamers of ionized particles
subtype: corona_discharge__corona__corposant__st.elmo'sfire__Saint_Elmo's_fire__Saint_Elmo's_light__Saint_Ulmo's_fire__Saint_Ulmo's_light__electric_glow an electrical discharge accompanied by ionization of surrounding atmosphere
subtype: propagation the movement of a wave through a medium
subtype: Doppler_effect__Doppler_shift change in the apparent frequency of a wave as observer and source move toward or away from each other
subtype: red_shift__redshift (astronomy) a shift in the spectra of distant galaxies toward longer wavelengths; generally interpreted as the Doppler effect resulting from the velocity at which they recede as the universe expands
subtype: wave_front all the points just reached by a wave as it propagates
subtype: fundamental_interaction__interaction (physics) the transfer of energy between elementary particles or between an elementary particle and a field or between fields; mediated by gauge bosons
subtype: electromagnetic_interaction__electromagneticinteraction an interaction between charged elementary particles that is intermediate in strength between the strong and weak interactions; mediated by photons
subtype: gravitational_interaction__gravitationalinteraction a weak interaction between particles that results from their mass; mediated by gravitons
subtype: strong_interaction__strong_force__color_force__colorforce (physics) the interaction that binds protons and neutrons together in the nuclei of atoms; mediated by gluons
subtype: weak_interaction__weak_force (physics) an interaction between elementary particles involving neutrinos or antineutrinos that is responsible for certain kinds of radioactive decay; mediated by intermediate vector bosons
subtype: surface_tension__surfacetension a phenomenon at the surface of a liquid caused by intermolecular forces
subtype: capillarity__capillary_action__capillaryaction a phenomenon associated with surface tension and resulting in the elevation or depression of liquids in capillaries
subtype: interfacial_tension__interfacialtension__interfacial_surface_tension__interfacialsurfacetension surface tension at the surface separating two non-miscible liquids
subtype: syzygy the straight line configuration of 3 celestial bodies (as the sun and earth and moon) in a gravitational system
subtype: transparence__transparency permitting the free passage of electromagnetic radiation
subtype: turbulency__turbulence unstable flow of a liquid or gas
subtype: tide_rip__rip__riptide__crosscurrent a stretch of turbulent water in the sea
subtype: floatation__flotation the phenomenon of floating (remaining on the surface of a liquid)
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