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Eng ID Term Definition
2841
light (or lighted) beacon
See BEACON.
2842
light beam
A group of PENCILS of light, as those originating at the many points of an illuminated surface. A BEAM of parallel LIGHT RAYS is a special c... more
A group of PENCILS of light, as those originating at the many points of an illuminated surface. A BEAM of parallel LIGHT RAYS is a special case in which each PENCIL is of such small cross-section that it may be regarded as a RAY.
2843
light (or lighted) buoy
See BUOY.
2844
light characteristics
See CHARACTERISTICS OF LIGHT.
2845
lighted sound buoy
See BUOY.
2846
light float
A boat-like structure used instead of a light buoy in waters where strong streams or currents are experienced, or when a greater elevation t... more
A boat-like structure used instead of a light buoy in waters where strong streams or currents are experienced, or when a greater elevation than that of a light buoy is necessary.
2847
lighthouse
A distinctive structure on or off a COAST exhibiting a major LIGHT designed to serve as an AID TO NAVIGATION.
2848
light list
See LIST OF LIGHTS.
2849
lightning
Luminous manifes­tations accompanying a sudden electrical discharge which takes place from or inside a CLOUD or, less often, from high struc... more
Luminous manifes­tations accompanying a sudden electrical discharge which takes place from or inside a CLOUD or, less often, from high structures on the GROUND or from MOUNTAINS.
2850
light pencil
A bundle of LIGHT RAYS originating at, or directed to, a single point.
2851
light ray
The geometrical concept of a single element of light propagated in a straight line and of in­finitesimal cross-section; used in analytically... more
The geometrical concept of a single element of light propagated in a straight line and of in­finitesimal cross-section; used in analytically tra­cing the path of light through an OPTICAL SYSTEM.
2852
light sector
A sector in which a navigational LIGHT is visible. See ARC OF VISIBIL­ITY.
2853
lightship
A distinctively marked vessel anchored or moored at a charted point, to serve as an AID TO NAVIGATION. By night it displays a characteristic... more
A distinctively marked vessel anchored or moored at a charted point, to serve as an AID TO NAVIGATION. By night it displays a characteristic LIGHT(S), and is usually equipped with other devices, such as a FOG SIGNAL, SUBMARINE SOUND SIGNAL, and RADIOBEACON, to assist NAVIGATION. Also called light vessel.
2854
light vessel
See LIGHTSHIP.
2855
light-year
A unit of length equal to the distance light travels in one YEAR. This unit is used as a measure of stellar distance.
2856
Lighter Aboard Ship (LASH)
A cargo carrying system using specially built ships and lighters. Cargoes are loaded into LASH lighters which are towed to a LASH ship where... more
A cargo carrying system using specially built ships and lighters. Cargoes are loaded into LASH lighters which are towed to a LASH ship where they are embarked. At their destination the LASH lighters are disembarked and towed away to their unloading berths. Special berths or anchorages are sometimes designated for LASH ships.
2857
limb
The graduated curved part of an instrument for measuring angles, as that part of a MARINE SEXTANT carrying the altitude scale, or arc. The c... more
The graduated curved part of an instrument for measuring angles, as that part of a MARINE SEXTANT carrying the altitude scale, or arc. The circular outer edge of a CELESTIAL BODY. The half with the greatest ALTITUDE is called the upper limb and the half with the least ALTITUDE, the lower limb.
2858
limestone
A ROCK which consists chiefly of calcium carbonate.
2859
limnology
The scientific study of the biological, chemical, geographical, and physical features of fresh waters, especially of LAKES and PONDS.
2860
linear light
See LIGHT.