hypothesis : Idioms & Phrases

• noun the principle that equal volumes of all gases (given the same temperature and pressure) contain equal numbers of molecules
  Avogadro's law.
  

WordNet

• . (Geol.) See Glacier theory, under Glacier.

Webster 1913

• noun (cosmology) the theory that the solar system evolved from a hot gaseous nebula
  

WordNet

• an hypothesis to explain the process of formation of the stars and planets, presented in various forms by Kant, Herschel, Laplace, and others. As formed by Laplace, it supposed the matter of the solar system to have existed originally in the form of a vast, diffused, revolving nebula, which, gradually cooling and contracting, threw off, in obedience to mechanical and physical laws, succesive rings of matter, from which subsequently, by the same laws, were produced the several planets, satellites, and other bodies of the system. The phrase may indicate any hypothesis according to which the stars or the bodies of the solar system have been evolved from a widely diffused nebulous form of matter.

Webster 1913

• noun (cosmology) the theory that the solar system was formed by the gravitational accumulation of planetesimals
  

WordNet