haftbar (#), haftguš (#)
Herbig AeBe star
setâre-ye Herbig-e AeBe (#)
Fr.: étoile de Herbig AeBe
A young → A-type or → B-type star showing → emission lines in its spectrum. Herbig AeBe stars are → pre-main sequence stars of → intermediate mass (→ intermediate-mass star). They are often called the higher mass counterparts of → T Tauri stars.
Fr.: objets Herbig-Haro
A small patch of → nebulosity in a → star-forming region, created when fast-moving → jets of material (with speeds up to about 1000 km per sec) from a newborn star collide with the → interstellar medium.
Herâkles (#), Herkul (#), bar zânu nešasté (#)
An ancient → constellation (right ascension about 17h,
declination 30° north), one of the largest in the sky, which is located between
→ Lyra and → Corona Borealis.
It is traditionally depicted as the hero Hercules in a kneeling position.
There are no very bright stars in Hercules, the brightest one is
→ Rasalgethi, a variable
→ red supergiant of magnitude about 3.5.
Abbreviation: Her; Genitive: Herculis.
L. Hercules, from Gk. Heracles "glory of Hera," the most popular hero of Gk. mythology, son of Zeus and the woman Alcmena, who the god seduced in the shape of her husband Amphitryon, king of Thebes.
Herâkles, as above; Herkul, from Fr. Hercule, as above;
Arabicized name of the constellation:
xuše-ye Herâkles, ~ Herkul
Fr.: amas d'Hercule
A small, irregular → cluster of galaxies with fewer than 100 galaxies in its core. It has no strongly dominant central galaxy and is notable for the high proportion of spirals. It lies some 500 million → light-years away in the constellation → Hercules; also known as Abell 2151.
Fr.: dont on peut hériter, qui peut hériter
1) Passing, or capable of passing, naturally from parent to offspring through the genes:
Blue eyes are hereditary in our family.
Of or relating to → heredity.
The passing on of physical or mental characteristics genetically from one generation to another (OxfordDictionaries.com).
M.E., from M.Fr. hérédité, from O.Fr. eredite "inheritance, legacy," from L. hereditatem (nominative hereditas) "heirship, inheritance," → heritage.
Fr.: dont on peut hériter, qui peut hériter
1) Something inherited at birth, such as personal characteristics,
status, and possessions.
M.E. from M.Fr., from O.Fr. iritage, eritage, heritage "heir; inheritance, ancestral estate, heirloom," from heriter "inherit," from L.L. hereditare, ultimately from L. heres (genitive heredis) "heir, heiress," from PIE root *ghe- "to be empty, left behind" (related Gk. word khera "widow").
Rigan from rig "left, abandoned" (in mordé rig "heritage, effects of a dead person, anything hereditary, heirloom") + noun suffix -an (as in rowzan, rowšan, suzan, rasan, zaqan, hâvan, etc.); ultimately from Proto-Ir. *raic- "to leave, abandon;" cf. Av. raēc- "to leave, let;" Mid.Pers. (+ *pati-) phryz-, Mod.Pers. parhêz, parhiz "to keep away from, abstain, avoid;" Khotanese (+ *fra-) hars- "to be left, remain;" Mod.Pers. rištan "to set at liberty, absolve;" Mid.Pers. (+ *ui-) wirēz-, Mod.Pers. gurēz, goriz, gurēxtan, gorixtan "to flee, run away;" Gk. leipein "to leave;" L. linquere "to leave;" PIE *leikw- "to leave, let" (Cheung 2006).
Of or related to hermeneutics, interpretative; explanatory. Also hermeneutical.
The science or art of → interpretation. Originally the term was limited to the interpretation of the Scriptures, but since the nineteenth century it has developed into a general theory of human understanding through the work of Friedrich Schleiermacher (1768-1834), Wilhelm Dilthey (1833-1911), and others. The comprehension of any written text requires hermeneutics. Many different hermeneutic theorists have proposed many different methodologies.
From Gk. hermeneutikos "interpreting," from hermeneutes "interpreter," from hermeneuein "to interpret," of unknown origin. It was formerly thought to derive from Hermes, the tutelary divinity of speech, writing, and eloquence.
Someone who interprets literary or scriptural texts.
Agent noun from → hermeneutics
Fr.: conjugé hermitien
Math.: The Hermitian conjugate of an m by n matrix A is the n by m matrix A* obtained from A by taking the → transpose and then taking the complex conjugate of each entry. Also called adjoint matrix, conjugate transpose. → Hermitian operator.
Hermitian, named in honor of the Fr. mathematician Charles Hermite (1822-1901), who made important contributions to number theory, quadratic forms, invariant theory, orthogonal polynomials, elliptic functions, and algebra. One of his students was Henri Poincaré; → conjugate.
Fr.: opérateur hermitien
An operator A that satisfies the relation A = A*, where A* is the adjoint of A. → Hermitian conjugate.
Fr.: Satellite Herschel
A European Space Agency (ESA) mission to perform imaging photometry and spectroscopy in the → far infrared and → submillimeter regions of the electromagnetic spectrum, covering approximately the 55-672 µm range. In fact Herschel is the first space facility dedicated to these wavelength ranges. It carries a 3.5 m diameter passively cooled mirror. The science payload complement - two cameras/medium resolution spectrometers (PACS and SPIRE) and a very high resolution → superheterodyne spectrometer (HIFI) - are housed in a superfluid helium cryostat. Herschel was launched on 14 May 2009, together with the → Planck Satellite. Its observing position lies at the L2 → Lagrangian point, some 1.5 million km from Earth. Herschel is designed, among other things, to study the formation of galaxies in the early Universe, and to investigate the formation of stars and their interaction with the → interstellar medium.
Named jointly after Sir William Herschel (1738-1822), German-born English astronomer, the discoverer of the → infrared radiation and planet → Uranus, and his sister and observing partner Caroline; → satellite.
The SI unit of frequency, defined as a frequency of 1 cycle per second.
After Heinrich Rudolf Hertz (1857-1894), the German physicist, who made several important contributions to the study of electromagnetism.
âzmâyeš-e Hertz (#)
Fr.: expérience de Hertz
A laboratory experiment carried out by Heinrich Hertz in 1888 to generate and detect → electromagnetic waves for the first time. It involved a high voltage power source, consisting of two → capacitors, each provided with a conducting rod. The rods were separated by a small → spark gap and connected to an → induction coil. When the electrodes were raised to a sufficiently high → potential difference, a spark passed across the gap, and an oscillating discharge took place. A group of waves with a wavelength of a few meters were emitted at each discharge. A wire loop provided with a detecting spark gap, held away from the oscillating sparks, produced sparks upon arrival of the oscillating electric and magnetic fields.
hertz to meter conversion
hâgard-e hertz bé metr
Fr.: conversion hertz / mètre
Fr.: oscillateur hertzien
An electrical system used for the production of → electromagnetic waves. It consists of two equal → capacitors connected to two electrodes with a → spark gap between the electrodes. The system is connected to an → induction coil. When the induction coil is activated, electromagnetic waves are generated across the spark gap. See also → Hertz experiment.