ad hoc hypothesis engâre-ye pad im Fr.: hypothèse ad hoc Addition of adjustments to a theory to save it from being falsified by compensating for anomalies not anticipated by the theory in its unmodified form. Theories that rely on continual, ad hoc adjustments are distrusted. → ad hoc; → hypothesis. |
alternative hypothesis engâre-ye degarine Fr.: hypothèse alternative Statistics: In → significance testing, any hypothesis which differs from the one being tested. A hypothesis alternative to the → null hypothesis is denoted by H_{1}. → alternative; → hypothesis. |
de Broglie hypothesis engâre-ye de Broglie Fr.: hypothèse de de Broglie The suggestion by Louis de Broglie in 1924 whereby if → electromagnetic waves possess particle properties (→ particle nature), then it might be reasonable to suppose that material particles, such as → electrons, should possess wave properties (→ wave nature). The de Broglie hypothesis was based on the intuitive feeling that nature seems to have strong attachment to symmetry. In other words, if radiation has particle-like properties, then material particles should possess wave-like properties. At the time no direct experimental evidence was present for the validity of this suggestion. The first confirmation of de Broglie's hypothesis was provided by the → Davisson-Germer experiment. See also → wave-particle duality; |
hypothesis engâre (#), upâdâyan Fr.: hypothèse A statement which is based on previous observations and which serves as a starting point for further investigation by which it may be proved or disproved. See also → theory, → model, → ad hoc hypothesis, → Kant-Laplace hypothesis, → arge number hypothesis, → nebular hypothesis, → null hypothesis, → statistical hypothesis, → statistical hypothesis testing. Hypothesis, from M.Fr. hypothèse, from L.L. hypothesis, from Gk. hypothesis "base, basis of an argument, supposition," literally "a placing under," from → hypo- "under" + thesis "a placing, proposition," from root of tithenai "to place, put, set," didomi "I give;" from PIE base *dhe- "to put, to do;" cf. Mod.Pers. dâdan "to give," Mid.Pers. dâdan "to give," O.Pers./Av. dā- "to give, grant, yield," dadāiti "he gives;" Skt. dadáti "he gives;" L. dare "to give, offer," facere "to do, to make;" Rus. delat' "to do;" O.H.G. tuon, Ger. tun, O.E. don "to do." Engâré, from engâridan, engâštan
"to → suppose." |
Kant-Laplace hypothesis engâre-ye Kant-Laplace Fr.: hypothèse de Kant-Laplace The hypothesis of the origin of the solar system proposed first by Kant (1755) and later by Laplace (1796). According to this hypothesis, the solar system began as a nebula of tenuous gas. Particles collided and gradually, under the influence of gravitation, the condensing gas took the form of a disk. Larger bodies formed, moving in circular orbits around the central condensation (the Sun). Named after the German prominent philosopher Immanuel Kant (1724-1804) and the French great mathematician, physicist, and astronomer Pierre-Simon Marquis de Laplace (1749-1827); → hypothesis. |
large number hypothesis engâre-ye adadhâ-ye bozorg Fr.: hypothèse des grands nombres The idea whereby the coincidence of various → large numbers would bear a profound sense as to the nature of physical laws and the Universe. Dirac suggested that the coincidence seen among various large numbers of different nature is not accidental but must point to a hitherto unknown theory linking the quantum mechanical origin of the Universe to the various cosmological parameters. As a consequence, some of the → fundamental constants cannot remain unchanged for ever. According to Dirac's hypothesis, atomic parameters cannot change with time and hence the → gravitational constant should vary inversely with time (G∝ 1/t). Dirac, P. A. M., 1937, Nature 139, 323; 1938, Proc. R. Soc. A165, 199. → large; → number; → hypothesis. |
nebular hypothesis engâre-ye miq Fr.: hypothèse nébulaire The hypothesis first put forward in the 18-th century that the solar system formed from a primeval nebula around the Sun. Same as the → Kant-Laplace hypothesis. → nebular; → hypothesis. |
no boundary hypothesis engâre-ye giti bi karân-e âqâzin Fr.: l'hypothèse de l'Univers sans limite initiale The proposal whereby the → Universe would not have begun with a → singularity. Instead, the → Big Bang would be an ordinary point of → space-time. The proposal, advanced by James Hartle and Stephen Hawking (1983) results from an attempt to combine aspects of → general relativity and → quantum mechanics. Based on an imaginary time assumption, it predicts a closed Universe that would start at a single point, that can be compared to the North Pole of the Earth on a two-dimensional space. Before the → Planck era there was space, but the real time began with the Big Bang event. → Hartle-Hawking initial state. → boundary; → hypothesis. |
null hypothesis engâre-ye nul Fr.: hypothèse nulle Statistics: The assumption of the absence of a particular pattern in a set of data. The null hypothesis, denoted by H_{0}, is put forward to be rejected in order to support an → alternative hypothesis. → null; → hypothesis. |
statistical hypothesis engâre-ye âmâri Fr.: hypothèse statistique An assumed statement about the way a → random variable is distributed. A statistical hypothesis generally specifies the form of the → probability distribution or the values of the parameters of the distribution. The statement may be true or false. See also → null hypothesis. → statistical; → hypothesis. |
statistical hypothesis testing âzmun-e engâre-ye âmâri Fr.: test d'hypothèse statistique A method of making decision between rejecting or not rejecting a → null hypothesis on the basis of a set of observations. → statistical; → hypothesis; → test. |