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

Of or pertaining to → aerodynamics.

→ aerodynamics.

The force exerted by a gaseous fluid upon a body completely immersed in it caused by their relative motion. The components of aerodynamic force are: → lift and → drag.

→ aerodynamic; → force.

The science that is concerned with the study of the → motion of → air and other gaseous → fluids and with the → forces acting on bodies moving through such fluids.

Aerodynamics, from Gk. aero-, → air, + → dynamics.

The science dealing with the motion of satellites, rockets, and spacecrafts. It uses the principles of celestial mechanics.

Astrodynamics, from → astro- "star" + → dynamics.

Axtartavânik, from axtar, → astro-, + tavânik, → dynamics.

A time scale previously used in calculations of the orbits of solar system objects (planets, asteroids, comets, and interplanetary spacecrafts). It was based on the Terrestrial Dynamical Time, but took the relativistic effect of time dilation into account to move the origin to the solar system barycenter. It is now superseded by → Barycentric Coordinate Time (TCB).

→ barycenter; → dynamical; → time.

A → quantum field theory of the → interaction of → quarks possessing a distinctive property called → color, in which the quarks exchange → gluons in a manner that is analogous to the interaction of → charged particles in → electrodynamics.

→ chromo-; → dynamics.

A → dynamical variable which has an → imaginary number part.

→ complex; → dynamical; → variable.

1) Involving or relating to force related to motion.
2) Pertaining to the science of → dynamics.

From Fr. dynamique, from Ger. dynamisch, introduced by Leibnitz in 1691, from Gk. dynamikos "powerful," from dynamis "power," from dynasthai "be able to have power" + → -ic.

Tavânik, from tavân "power, strength," tavânestan "to be powerful, able," + Pers. suffix -ik; → -ics. The first component from Mid.Pers. tuwan "power, might," from O.Pers./Av. base tav- "to have power, to be strong, to be able," Av. tavah- "power," təviši- "strength," Mod.Pers. tuš, tâb "power, ability," O.Pers. tauman- "power, strength," tunuvant- "powerful," Skt. tu- "to be strong, to have authority," tavas-, tavisa- "strong, energetic," tavisi- "power, strength" + -ik→ -ic.

Mechanics: The condition of a moving mechanical system when the accelerating force is balanced by an imaginary kinetic reaction according to → d'Alembert's principle. See also → static equilibrium; → thermodynamic equilibrium.

Dynamic, adj. from → dynamics; → equilibrium.

A measure of the extent to which mass has been shifted from the polar regions of a (spinning) body toward its equator (Ellis et al., 2007, Planetary Ring Systems, Springer).

→ dynamic; → oblateness.

A property of a moving → fluid defined by (1/2)ρv² in → Bernoulli's law, where ρ is → density of fluid and v is → velocity. Dynamic pressure is the difference between → total pressure and → static pressure. Also called → velocity pressure. → ram pressure.

→ dynamic; → pressure.

The ratio of the maximum to minimum signal levels present in an image. For instance, a true 12-bit digital camera is capable of providing a dynamic range of 4096 to 1.

Adj. of → dynamics; → range.

Same as → viscosity and → absolute viscosity.

→ dynamic; → viscosity.

Of or pertaining to force or power; of or pertaining to force related to motion.
Pertaining to the science of dynamics. Same as dynamic.

Adj. from → dynamics.

Age based on dynamical properties of a system. For example, the time derived for a system to evolve from an initial state to its present state, based on velocity and dimension (size) measurements.

→ dynamical; → age.

The process whereby a → bound system, such as a → binary system or a → globular cluster, is broken apart.

→ dynamical; → disruption.

Of a physical system, a condition in which the parts of the system are in continuous motion, but they move in opposing directions at equal rates so that the system as a whole remains in equilibrium.

→ dynamical; → equilibrium.

The gravitational interaction between a relatively massive body and a field of much less massive bodies through which the massive body travels. As a result, the moving body loses → momentum and → kinetic energy. An example of dynamical friction is the sinking of massive stars to the center of a → star cluster, a process called → mass segregation. Dynamical friction plays an important role in → stellar dynamics. It was first quantified by Chandrasekhar (1943).

→ dynamical; → friction.

A law that describes the motion of individual particles in a system, in contrast to → statistical laws.

→ dynamical; → law.

The mass of an object derived indirectly from theoretical formulae based on the laws governing the behavior of a → dynamical system.

→ dynamical; → mass.