An Etymological Dictionary of Astronomy and Astrophysics
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فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory

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Number of Results: 5 Search : Big Bang
Big Bang
  مه بانگ، بیگ بنگ   
Meh Bâng (#), Big Bang (#)

Fr.: Big Bang   

A theory which states that the → Universe came into existence in an "instantaneous" event some 14 billion years ago. Matter was created in that initial event and as time has gone by the Universe has expanded and the contents evolved into the galaxies and stars and of today. The Big Bang is sometimes described as an "explosion." However, matter and energy did not erupt into a pre-existing space, since they came into being simultaneously with space and time.

big; bang "a sudden loud noise, as of an explosion" (probably of Scandinavian origin; akin to Icelandic banga "to hammer"). The term was coined by Fred Hoyle in 1950 in the course of discussions entitled "the Nature of the Universe" broadcasted by BBC. Hoyle's intention was a pejorative term in order to ridicule the theory which his own → steady state theory contested.

Meh Bâng, from meh "great, large," → big, + bâng "voice, sound, clamour," (Mid.Pers. vâng, Av. vaocanghê "to declare (by means of speech"), vacah- "word," from vac- "to speak, say," cf. Mod.Pers. vâžé "word," âvâz "voice, sound, song," Skt. vakti "speaks, says," vacas- "word;" Gk. epos "word," L. vox "voice;" PIE base *wek- "to speak").

Big Bang model
  مدل ِ مه بانگ، ~ بیگ بنگ   
model-e Meh Bâng, ~ Big Bang

Fr.: modèle du big bang   

Big Bang; → model.

Big Bang nucleosynthesis (BBN)
  هسته‌هندایش ِ مهبانگ، ~ بیگ بنگ   
haste-handâyeš-e Meh Bâng, ~ Big Bang

Fr.: nucléosynthèse de Big Bang   

The production of → light elements, roughly three minutes after the → Big Bang when the temperature of the → Universe dropped from 1032 K to approximately 109 K. In a short time interval → protons and → neutrons collided to produce → deuterium. Most of the deuterium then fused with other protons and neutrons to produce → helium and a small amount of → tritium. The element → lithium 7 could also arise form the coalescence of one tritium and two deuterium nuclei. According to the Big Bang nucleosynthesis theory, roughly 25% of the mass of the Universe consists of helium. It also predicts about 0.01% deuterium, and even smaller quantities of lithium. These predictions depend critically on the → baryon-photon ratio. Same as → primordial nucleosynthesis.

Big Bang; → nucleosynthesis.

Big Bang singularity
  تکینی ِ بیگ بنگ   
takini-ye Big Bang

Fr.: singularité du Big Bang   

A hypothetical state of → infinite energy density representing an infinite → gravitational field and infinite → space-time curvature. The singularity arises from using Einstein's theory of → general relativity concerning gravity. We know, however, that when the density and heat become extremely large, quantum physics of gravity becomes important. Yet Einstein's equations ignore quantum effects. In other words, in certain extreme conditions, Einstein's equations do not apply.

Big Bang; → singularity.

Big Bang theory
  نگره‌ی ِ مه بانگ، ~ بیگ بنگ   
negare-ye Meh Bâng, ~ Big Bang

Fr.: théorie du big bang   

Big Bang; → theory.