An Etymological Dictionary of Astronomy and AstrophysicsEnglish-French-Persian

فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory

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Number of Results: 44 Search : logic
 analogical   آناگوییک   ânâguyikFr.: analogique   Of, relating to, or based on analogy; expressing or implying analogy.→ analogy + -i + → -al. anisotropic homogeneous cosmological model   مدل ِ کیهانشناختی ِ همگن و نا-ایزوگرد   model-e keyhânšenâxti-ye hamgen o nâ-izogardFr.: modèle cosmiologique homogène mais anisotrope   A solution to Einstein's theory of → general relativity that is spatially homogeneous but allows for rotation and/or shear. See also → Bianchi cosmological model.→ anisotropic; → homogeneous; → cosmological; → model. asteroseismologic   اخترلرزه‌شناسی، اخترلرزه‌شناسیک   axtarlarzešenâsi, axtarlarzešenâsikFr.: astérosismologique   Of or relating to → asteroseismology.→ spectropolarimetry; → -ic. Bianchi cosmological model   مدل ِ کیهانشناختی ِ بیانکی   model-e keyhânšenâxti-ye BianchiFr.: modèle cosmologique de Bianchi   A cosmological model based on the theory of → general relativity, which is homogeneous but → anisotropic. There are actually ten dinstinct Bianchi types, classified according to the particular kinds of symmetry they posses.Luigi Bianchi (1856-1928), Italian mathematician; → cosmological; → model. bivalent logic   گوییک ِ دو-ارز   guyik-e do-arzFr.: logique bivalente   A logical system, such as → classical logic, in which every declarative sentence expressing a → proposition has exactly one → truth value, either → true or → false. Bivalent logic is just a sub-set of a more powerful type of logic known as → fuzzy logic. See also → polyvalent logic.→ bivalent; → logic. classical logic   گوییک ِ کلاسیک   guyik-e kelâsikFr.: logique classique   The traditional logic in which → sets are sharply defined (→ crisp set) for example, the number of students registered for a course, or the names beginning with P in a given telephone directory. Classical logic also defines relations between sets of → propositions. Consider for example two sets: elephants and mammals, a simple proposition would be the assertion that all elephants are mammals, that is E ⊂ M, where E is the elephant set and M is the mammal set. The classical logic proposition is either true or false. Compare with → fuzzy logic.→ classical; → logic. cosmological   کیهان‌شناختی، کیهان‌شناسیک   keyhânšenâxti, keyhânšenâsikFr.: cosmologique   Pertaining or relating to → cosmology.→ cosmology; → -al. cosmological constant   پایای ِ کیهان‌شناسیک، ~ کیهان‌شناختی   pâyâ-ye keyhânšenâsik, ~ keyhânšenâxtiFr.: constante cosmologique   A term introduced by Einstein into his gravitational → field equations in order to allow a solution corresponding to a → static Universe. The cosmological constant is physically interpreted as due to the → vacuum energy of quantized fields. See also → dark energy.→ cosmological; → constant. cosmological constant problem   پراسه‌ی ِ پایای ِ کیهانشناختی   parâse-ye pâyâ-ye keyhânšenâxtiFr.: problème de la constante cosmologique   The impressive discrepancy of about 120 orders of magnitude between the theoretical value of the → cosmological constant and its observed value. → Quantum field theory interprets the cosmological constant as the density of the → vacuum energy. This density can be derived from the maximum energy at which the theory is valid, i.e. the → Planck energy scale (1018 GeV). The theoretical vacuum → energy density is (1018 GeV)4 = (1027 eV)4 = 10112 erg cm-3. On the other hand, the observed vacuum energy density is estimated to be about (10-3 eV)4 = 10-8 erg cm-3. There is, therefore, a discrepancy of about 120 orders of magnitude.→ cosmological; → constant; → problem. cosmological distance   دورای ِ کیهان‌شناسیک، ~ کیهان‌شناختی   durâ-ye keyhânšenâsik, ~ keyhânšenâxtiFr.: distance cosmologique   The distance to a remote galaxy based on its redshift assuming that the redshift is caused by the → Doppler effect and reflects the general expansion of the Universe.→ cosmological; → distance . cosmological epoch   زیمه‌ی ِ کیهانشناختی   zime-ye keyhânšenâxtiFr.: époque cosmologique   → cosmological; → epoch. cosmological model   مدل ِ کیهان‌شناسیک، ~ کیهان‌شناختی   model-e keyhânšenâsik, ~ keyhânšenâxtiFr.: modèle cosmologique   A mathematical description of the Universe, based on observation, which tries to explain its current aspect, and to describe its evolution during time.→ cosmological; → model. cosmological principle   پروز ِ کیهان‌شناسیک، ~ کیهان‌شناختی   parvaz-e keyhânšenâsik, ~ keyhânšenâxtiFr.: principe cosmologique   The → hypothesis that on → large scales the → Universe is → isotropic and → homogeneous, that is, it appears the same at all places and, from any one place, looks the same in all directions. See also → perfect cosmological principle.Introduced by E.A. Milne in 1933; → cosmological; → principle. cosmological redshift   سرخ کیب ِ کیهان‌شناسیک، ~ کیهان‌شناختی   sorxkib-e keyhânšenâsik, ~ keyhânšenâxtiFr.: décalage vers le rouge cosmologique, redshift ~   The → redshift of a remote object (galaxy, quasar, supenova) due to the expansion of the Universe.→ cosmological; → redshift. current cosmological epoch   زیمه‌ی ِ کیهانشناختی ِ کنونی   zime-ye keyhânšenâxti-ye konuniFr.: époque cosmologique actuelle   The → Universe at the → redshift z = 0.→ current; → cosmological; → epoch. first-order logic (FOL)   گوییک ِ فراسنی ِ رایه‌ی ِ نخست، ~ فراسنهای ِ ~ ~   guyik-e farâsani-ye râye-ye naxost, ~ farâsanhâ-ye ~ ~Fr.: logique des prédicats du premier ordre   A system of → formal logic that is an extension of → propositional logic. It is also known as → first-order predicate calculus and → predicate logic. FOL eliminates deficiencies of propositional logic by: representing → objects (their properties, relations and statements about them), introducing → variables, and introducing → quantifiers.→ first; → order; → predicate; → logic. formal logic   گوییک ِ دیسه‌ای، ~ دیسه‌ور   guyik-e diseyi, ~ disevarFr.: logique formelle   The traditional or → classical logic in which the → validity or → invalidity of a conclusion is deduced from two or more statements (→ premises). Based on Aristotle's (384-322 BC) theory of → syllogism, systematized in his book "Organon," its focus is not on what is stated (the content) but on the structure (form) of the → argument and the validity of the inference drawn from the premises of the argument; if the premises are true then the logical consequence must also be true. Formal logic is → bivalent, that is it recognizes only two → truth values: → true and → false. The basic principles of formal logic are: 1) → principle of identity, 2) → principle of excluded middle, and 3) → principle of non-contradiction. See also → symbolic logic, → fuzzy logic.→ formal; → logic. fuzzy logic   گوییک ِ پرزوار   guyik-e porzvârFr.: logic flou   A mathematical logic that recognizes more than simple → true and → false → propositions. With fuzzy logic, propositions can be represented with degrees of truthfulness and falsehood. In this system, → truth values are → fuzzy sets without sharp boundaries (→ crisp set) in contrast with → classical logic. Fuzzy logic is applied to a wide range of problems including: industrial control, domestic goods, decision making, robotics, intelligent machines, and image processing in medicine.→ fuzzy; → logic. fuzzy logic system   راژمان ِ گوییک ِ پرزوار   râžmân-e guyik-e porzvârFr.: système de logic flou   An engineering system which uses → fuzzy logic. It generally consists of four main components: → fuzzification interface (fuzzifier), → fuzzy rule base, → fuzzy inferencing unit, and → defuzzification interface (difuzzifier). Also called → fuzzy inference system.→ fuzzy; → logic; → system. geologic   زمین‌شناختی   zaminšenâxti (#)Fr.: géologique   Of, pertaining to, or based on → geology. Also geological.From geolog(y), → geology, + → -ic.

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