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

A collision between bodies in which there is a loss of total kinetic energy.

→ inelastic; → collision.

A type of scattering when the → scattered radiation has a → wavelength different from that of the → incident radiation (→ Raman scattering, → fluorescence ).

→ inelastic; → scattering.

1) A statement of the form a ≠ b, a > b, or a < b, asserting one quantity is greater than or less than another quantity. → equality.
2) An irregularity in the movement of a celestial object in its orbit about another which cannot be explained by their mutual gravitational attraction. Irregularities are often due to perturbation by other neighboring objects.

→ in-; → equality.

Having no inherent power of action, motion, or resistance (opposed to active).
Chemistry: A chemically inactive element, compound or material. → inert gas.

Inert, from Fr. inerte, from L. inertem "unskilled, inactive," from → in- "without" + ars (gen. artis) "skill."

Laxt "sluggish, inert."

Any one of six gases helium, neon, argon, krypton, xenon, and radon, all of whose atomic shells contain complete numbers of electrons so that the atoms are almost completely chemically inactive. Same as noble gases.

→ inert; → gas.

Tendency of a body to preserve its state of rest or uniform motion in a straight line.

Inertia, from L. inertia "un-skillfulness, idleness," from iners (gen. inertis) "unskilled, inactive;" → inert.

Laxti "sluggishness, inertia."

An ellipsoid used in describing the motion of a rotating rigid body. It is stationary with respect to the rotating body, and is determined by the body's moments of inertia.

→ ellipsoid; → inertia.

Of or relating to inertia.

From → inertia + → -al.

Laxt, adj. of laxti, → inertia

A force arising from the → acceleration of an observer's → frame of reference.

→ inertial; → force.

→ inertial reference frame.

→ inertial; → frame.

The mass of a body as determined from the acceleration of the body when it is subjected to a force that is not due to gravity.

→ inertial; → mass.

Motion free of any force, with constant velocity.

→ inertial; → motion.

1) A periodic motion of a particle that moves, free from external forces, over the surface of a rotating sphere, such the Earth. Inertial oscillations result from the → Coriolis force. For example, a hockey puck launched on a big enough lake in the northern hemisphere would turn to the right (east) and eventually loop back to nearly the initial point (actually west of that point). The time it takes for the huckey puck to return can be computed with the → Coriolis frequency.
2) Meteo.: An anticyclonic (clockwise) rotation in the northern hemisphere, with the Coriolis force providing the → centripetal acceleration with period of 2π/f, where f is the Coriolis frequency. The opposite should occur in the southern hemisphere.

→ inertial; → oscillation.

A → reference frame or coordinate system in which there are no accelerations, only zero or uniform motion in a straight line. According to the special theory of relativity, it is impossible to distinguish between such frames by means of any internal measurement.

→ inertial; → reference; → frame.

The fall of matter toward the center of a region of gravitational influence.

Infall, from → in- + → fall.

Darun-oft, from darun- "in, into; within" (Mid.Pers. andarôn "inside," from andar, → inter-, + rôn "side, direction;" Av. ravan- "(course of a) river") + oft, → fall.

To affect, cause infection, or contaminate with a pathogenic microorganism or agent.

M.E. infecten, from L. infectus, p.p. of inficere "to immerse in dye, discolor, taint, poison," from equivalent to → in- + → -fac, combining form of facere "to do, make," → fact, + -tus p.p. suffix; from PIE root *dhe- "to set, put."

Fažidan, infinitive from faž "dirt, filth, pus;" related word faže, fažnâk, fažgen, fažegen, fažgin, fažqand "filthy, dirty;" of unknown origin. It may be related to Proto-Ir. root *xard- "to defecate," with offshoots xard "muddy place," xarra "mud," (+ *pati-) payxâl "excrement."

1) A thing that infects or causes infection.
2) Causing infection; infecting.

→ infect; → -ant.

1) Affected with a disease-causing organism.
2) Computers: Affected with a → virus.

P. p. of → infect.

A branch of medicine that deals with the diagnosis, management and treatment of various infectious or contagious diseases.

→ infection; → -logy.

1) An act or fact of infecting; state of being infected.
2) An infecting agency or influence.
3) An infectious disease.
4) Computers: The presence of a virus in, or its introduction into, a computer system.

Verbal noun of → infect.