An Etymological Dictionary of Astronomy and Astrophysics
English-French-Persian

A hard translucent yellow, orange, or brownish-yellow fossil resin. Amber becomes negatively charged when rubbed with wool, because it attracts negative charges (electrons) and will take them from wool.

M.E. ambre, from O.Fr., from L. ambra, ambar, from Ar. 'anbar "ambergris, amber," from Mid.Pers. ambar, → ambergris.

Kahrobâ, from kah "straw" + robâ "attractor." The first component kah, kâh "straw, hay," from Mid.Pers. kâh "chaff, straw;" cf. Pali kattha- "a piece of wood;" Skt. kastha- "stick;" Gk. klados "twig;" O.Ir. caill "wood;" P.Gmc. *khulto-; Ger. Holz "wood;" E. holt; PIE *kldo-. The second component robâ, from robudan "to attract, to grab, rob;" Av. urūpaiieinti "to cause racking pain(?);" cf. Skt. rup- "to suffer from abdominal pain," rurupas "to cause violent pain," ropaná- "causing racking pain," rópi- "racking pain;" L. rumpere "to break;" O.E. reofan "to break, tear." In Arabic kahrobâ, a loanword from Persian, is used as equivalent for electricity.

A wax-like, ash-colored, strongly scent substance present in the intestines of → whales and found in seas or cast ashore. Used in perfumery.

From M.Fr. ambre gris "gray amber," → gray; → amber.

Anbar "ambergris," from Mid.Pers. ambar.

A tank filled with a transparent liquid that is on the brink of boiling. When a charged particle passes through the liquid, the energy deposited initiates boiling along the path, leaving a trail of tiny bubbles. The bubble chamber is no longer in wide use for particle experiments.

→ bubble; → chamber.

An enclosed space making part of a laboratory apparatus, such as → bubble chamber, → cloud chamber, → multiwire proportional chamber.

M.E., from O.Fr. chambre, from L.L. camera "a chamber, room."

Otâqak "small room, small chamber," cf. Sogdian ôtâk "place, region," ôtâkcik "local, regional, native" + -ak diminutive suffix.

An early type of → bubble chamber used for detecting particles of ionizing radiation. It was invented in 1900 by Charles Thomson Rees Wilson (1869-1959), a Scottish physicist, who along with Arthur Compton (1892-1962 ) received the Nobel Prize for physics in 1927.

→ cloud; → chamber.

A centimeter-gram-second (cgs) unit of luminance (or brightness) equal to 1/π candle per square centimeter. Physically, the lambert is the luminance of a perfectly diffusing white surface receiving an illuminance of 1 lumen per square centimeter.

Johann Heinrich Lambert (1728-1777), German scientist and mathematician; → law.

The intensity of the light emanating in any given direction from a perfectly diffusing surface is proportional to the cosine of the angle between the direction and the normal to the surface. Also called → Lambert's law.

→ lambert; → cosine; → law.

Same as → Lambert's cosine law.

→ lambert; → law.

A → planetary or → satellite disk with → Lambertian surface. Such a disk has the same → surface brightness at all angles.

→ lambert; → disk.

A surface whose → luminous intensity obeys → Lambert's cosine law. Such a source has a → reflectance that is uniform across its surface and uniformly emits in all directions from all its points. It appears equally bright from all viewing directions. Lambertian surface is a very useful concept for the approximation of radiant power transfer.

→ lambert; → surface.

A large cavity within the Earth's → crust containing → magma. When a → vent is opened to the surface, magma is extruded onto the surface as → lava.

→ magma; → chamber.

Same as → Charpak's detector.

→ multi-; → wire; → proportional; → chamber.

An enclosure from which air is removed.

→ vacuum; → chamber.