separ-e garmâyi (#), garmâ-separ
Fr.: bouclier thermique
A structure that protects against excessive heat, especially that which covers the vulnerable surfaces of a → spacecraft and protects it when re-entering the Earth's atmosphere.
Fr.: transfert de chaleur
The spontaneous transportation of heat through matter, from a region of higher temperature to a region of lower temperature.
celle-ye tâbestân (#)
Meteorology: A period of several successive days of abnormally hot and usually humid weather occurring in summer.
1) The process whereby a system's temperature increases.
The sky or Universe as seen from the Earth; the firmament. Often used in the plural.
From M.E. heven, O.E. heofon, possibly from P.Gmc. *khemina- (cf. M.L.G. heben, O.N. himinn, Goth. himins, Du. hemel, Ger. Himmel "heaven, sky"); PIE base *kem-/*kam- "to cover."
Âsmân, from Mid.Pers. âsmân "sky, heaven;" O.Pers. asman- "heaven;" Av. asman- "stone, sling-stone; heaven;" cf. Skt. áśman- "stone, rock, thunderbolt;" Gk. akmon "heaven, meteor, anvil;" Akmon was the father of Ouranos (Uranus), god of sky; Lith. akmuo "stone;" Rus. kamen; PIE base *akmon- "stone, sky." The link between the "stone" and "sky" concepts indicates that the sky had once been conceived as a stone vault by prehistoric Indo-Europeans.
Fr.: corps céleste
lâye-ye Heaviside (#)
Fr.: couche de Heaviside
English physicist Oliver Heaviside (1850-1925).
Of great weight; of great amount, quantity.
M.E. hevi; O.E. hefig, from P.Gmc. *khabigas (cf. O.N. hebig).
Sangin "heavy, weighty; stony, like stone, hard," from sang "stone, rock" (Mid.Pers. sang; O.Pers. aθanga-; Av. asenga- "stone" (related to Mod.Pers. âsmân "sky" → heaven); PIE *aken-) + -in adj. suffix.
bonpâr-e sangin (#)
Fr.: élément lourd
hidrožen-e sangin (#)
Fr.: hydrogène lourd
âb-e sangin (#)
Fr.: eau lourde
Water in which the hydrogen is replaced by → deuterium. Deuterium Oxide (D2O).
gâhšomâr-e yahud (#)
Fr.: calendrier hébreu
A → lunisolar calendar used by Jews for religious purposes. The year consists of 12 months alternating between 29 and 30 days, making a year of 354 days. In order to conform to the → solar year, a → leap month is included every third year. A month begins the day the new moon is first seen. The years are counted from the time of "creation," believed by Jewish theologians to have occurred in the year 3761 B.C. Also called → Jewish calendar.
Hebrew, from O.E., from O.Fr. Ebreu, from L. Hebraeus, from Gk. Hebraios, from Aramaic 'ebhrai, corresponding to Heb. 'ibhri "an Israelite," literally "one from the other side," in reference to the River Euphrates, or perhaps simply denoting "immigrant;" from 'ebher "region on the other or opposite side;" → calendar.
A prefix meaning hundred (102) used in the formation of compound words.
From Fr., from Gk. hekaton "hundred."
Hekto-, loanword from Fr., as above.
bolandi (#), bolandâ (#), farâzâ (#)
Distance upward from a given level to a fixed point.
M.E., from O.E. hiehthu; → high + -th a suffix forming nouns of action (e.g., birth) or abstract nouns denoting quality or condition (depth; length; warmth).
Bolandi, bolandâ "height," noun forms from boland
"high," variants bâlâ
"up, above, high, elevated, height," borz "height, magnitude"
(it occurs also in the name of the mountain chain Alborz),
Lori dialect berg "hill, mountain;"
Mid.Pers. buland "high;" O.Pers. baršan- "height;"
Av. barəz- "high, mount," barezan- "height;" cf.
Skt. bhrant- "high;" L. fortis "strong" (Fr. & E. force);
O.E. burg, burh "castle, fortified place," from P.Gmc.
*burgs "fortress;" Ger. Burg "castle," Goth. baurgs "city,"
E. burg, borough, Fr. bourgeois, bourgeoisie, faubourg);
PIE base *bhergh- "high."
Fr.: auréole, heiligenschein
A diffuse bright region surrounding the shadow that an observer's head casts on an irregular surface. It can be best observed on dewy reeds or grass. This phenomenon is reminiscent of the → glory, but without its color and regular structure.
Heiligenschein, Ger., literally "saint's shining light," from heiligen, from heilig "holy, sacred" (P.Gmc. *khailagas; M.H.G. heilec; O.H.G. heilag; Goth. hailag; O.N. heilagr; O.E. halig; E. holy) + Schein "glow, shine" (M.H.G. schinen, O.H.G. skinan, P.Gmc. *skinanan; E. shine; cf. Mod.Pers. sâyé "shadow;" Mid.Pers. sâyak "shadow;" Av. a-saya- "throwing no shadow;" Skt. chāya- "shadow;" Gk. skia "shade;" Rus. sijat' "to shine;" PIE base *skai- "bright").
Sepant foruq, from sepant "holy" (Mid.Pers. spand "holy," Spandarmat "Holy Thought; 5-th day of the month; 12-th month of the year;" from Av. spənta- "holy; beneficent," spəntô.mainyav- "coming from or belonging to the holy spirit," spəntô.təma- "holiest") + foruq "light, brightness" (related to rôšan "light; bright, luminous;" ruz "day," afruxtan "to light, kindle;" Mid.Pers. payrog "light, brightness," rošn light; bright," rôc "day;" O.Pers. raucah-; Av. raocana- "bright, shining, radiant," raocah- "light, luminous; daylight;" cf. Skt. rocaná- "bright, shining, roka- "brightness, light;" Gk. leukos "white, clear;" L. lux "light" (also lumen, luna; E. light, Ger. Licht, and Fr. lumière; PIE base *leuk- "light, brightness").
A person who inherits or has a right of inheritance in the property of another following the latter's death (Dictionary.com).
Heisenberg uncertainty principle
parvaz-e nâtâštigi-ye Heisenberg
Fr.: principe d'incertitude de Heisenberg
The uncertainty in the measurement of the position and momentum of an elementary particle. The more precisely one quantity is known, the less certain the precision of the other. A similarly linked pair of quantities is the time and energy content in a volume of space.
Named after Werner Heisenberg (1901-1976), the German physicist who in 1927 derived the uncertainty principle. In 1932 he was awarded the Nobel Prize in Physics; uncertainty, from → un- "not" + → certainty; → principle.
Heliacal "pertaining to the sun," from Gk. heliakos "of the sun," from helios, → sun; cognate with Pers. hur, as below.
Hurâné "sunlike," since the star rises in the morning like the Sun, from hur "sun", variant xor; Mid.Pers. xvar "sun;" Av. hû-, hvar- "sun;" Skt. surya-; L. sol; O.H.G. sunna; Ger. Sonne; E. sun; PIE *sawel- "sun" + -âné similarity suffix.
Fr.: lever héliaque
The first appearance of a star following a period of invisibility due to its conjunction with the Sun. → heliacal rising of Sirius.
heliacal rising of Sirius
barâyeš-e hurâne-ye Tištar
Fr.: lever héliaque de Sirius
The first rising of → Sirius at dawn shortly before → sunrise. The heliacal rising of Sirius played a significant role in ancient Egypt by heralding the annual flooding of the Nile. The event took place some 70 days after the star had been seen for the last time in the western horizon at sunset. The heliacal rising of Sirius and its association with the rebirth of the Nile was so important that it marked the start of the Egyptian calendar year. At the time, the heliacal rising occurred in early July, as seen from the ancient capital of Memphis. But due to the → precession of the equinoxes the star now reappears in early August in Egypt. The date depends on the latitude (assuming transparent skies), being later for higher latitudes. For latitude 48° it occurs on about August 19.