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: 8 Search : sonic
hypersonic
  هیپرصدایی   
hipersedâyi

Fr.: hypersonique   

In aerodynamics, adjective used to describe a → sound speed in excess of Mach 5. See also → supersonic.

Hypersonic, from → hyper- + → sonic.

sonic
  صدایی   
sedâyi (#)

Fr.: sonique   

Of, relating to, or being the speed of sound in a medium.

From L. sonus, → sound.

Sedâyi, pertaining to sedâ, → sound.

sonic boom
  غریو ِ صدا   
qariv-e sedâ (#)

Fr.: bang sonique   

A noise caused by a shock wave that emanates from an object traveling at or above the speed of sound.

sonic; boom, M.E. bombon, bummyn "to buzz;" cf. Du. bommen, Ger. bummen, word made by sound imitation.

Qariv "shout, clamour, cry;" sedâyi, → sonic.

sonic point
  نقطه‌ی ِ صدایی   
noqte-ye sedâyi

Fr.: point sonique   

The point where the → stellar wind makes a transition from → subsonic to → supersonic flow. In the particular case of a spherically symmetric wind (thus with no magnetic field), the distance from star, at which the sonic point occurs, is given by: rs = (GM*)/2cs2, where G is the → gravitational constant, M* is the stellar mass, and cs the → sound speed at the sonic point.

sonic; → point.

subsonic
  زیر-صدایی   
zir-sedâyi

Fr.: subsonique   

Describing a speed that is less than the speed of sound in the medium concerned. → supersonic.

sub-; → sonic.

subsonic flow
  تچان ِ زیر-صدایی   
tacân-e zir-sedâyi

Fr.: écoulement subsonique   

A flow in which the velocity of the constituting particles never exceeds that of sound in the same fluid. Also called subcritical flow.

subsonic; → flow.

supersonic
  اَبَر-صدایی   
abar-sedâyi

Fr.: supersonique   

Describing a speed that is greater than the → sound speed in the medium concerned. See also → Mach number, → subsonic.

super-; → sonic.

ultrasonics
  اولتر-صداییک، اولتر-سداییک   
ultar-sedâyik

Fr.: physique des ultra-sons   

The branch of physics dealing with elastic waves of frequencies above 20 kHz to 1010 kHz propagated in solids, liquids, and gases.

ultra-; sonic from L. sonussound + → -ics.