An Etymological Dictionary of Astronomy and Astrophysics
English-French-Persian

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

Hypersonic, from → hyper- + → sonic.

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

From L. sonus, → sound.

Sedâyi, pertaining to sedâ, → sound.

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.

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: r_s = (GM_*)/2c_s², where G is the → gravitational constant, M_* is the stellar mass, and c_s the → sound speed at the sonic point.

→ sonic; → point.

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

→ sub-; → sonic.

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.

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

→ super-; → sonic.

Of or pertaining to the speed of a body in a surrounding fluid when the relative speed of the fluid is → subsonic in some places and → supersonic in others.

→ trans-; → sonic.

Flow of a fluid over a body with a speed in the range just above and below the → Mach number 1.

→ transonic; → flow.

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. sonus→ sound + → -ics.