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

1) To press, to apply with pressure, especially to leave a mark.
2) To produce a profound effect upon the mind.

→ in-; → press.

1) A strong effect produced on the intellect, feelings, conscience, etc.
2) The first and immediate effect of an experience or perception upon the mind (dictionary.com).

→ press + -ion variant of → -tion.

Capable of being impressed; easily impressed.

→ impress; → -able.

1) A style of painting developed in the last third of the 19th century, characterized chiefly by short brush strokes of bright colors in immediate juxtaposition to represent the effect of light on objects.
2) A manner of painting in which the forms, colors, or tones of an object are lightly and rapidly indicated.
3) A manner of sculpture in which volumes are partially modeled and surfaces roughened to reflect light unevenly (Dictionary.com).

→ impression; → -ism.

Having the power to impress, to raise admiration, awe, respect, etc.

→ impress; → -ive.

Of a force acting on a body, the → product of the → force and the → time for which it acts. If the force changes with time, the impulse is the → integral of the force with respect to the time during which the force acts, and is equal to the total change of → momentum produced by the force: ∫F dt = ∫m dv. Impulse is a → vector quantity.

From L. impulsus "a push against, pressure, shock," p.p. of impellere "to push, strike against, drive forward," from → in- "into" + pellere "to push, drive."

Tekâné, from tekân "involuntary motion, sudden shaking," related to tak "rush, quick motion, stroke, blow" (tâxtan, tâzidan "to run; to hasten; to assault"); Mid.Pers. tak "assault, attack;" Av. taka- "leap, run," from tak- "to run, flow;" cf. Skt. tak- "to rush, to hurry," takti "runs;" O.Ir. tech- "to flow;" Lith. teketi "to walk, to flow;" O.C.S. tešti "to walk, to hurry;" Tokharian B cake "river;" PIE base *tek^w- "to run; to flow;" → flow.

The vector → impulse of the → resultant force on a particle, in any time interval, is equal in magnitude and duration to the vector change in momentum of the particle: ∫F dt = mv₂ - mv₁. The impulse-momentum principle finds its chief application in connection with forces of short duration, such as those arising in collisions or explosions. Such forces are called → impulsive forces.

→ impulse; → momentum; → principle.

Relating to → impulse, the force which is very large but acts for a very short time.

Impulsive, adj. of → impulse; → force.

A substance that is incorporated into a semiconductor material to provide free electrons (n-type impurity) or holes (p-type impurity).

Impurity, from im- negation prefix, → in-, + purity, O.Fr. pureté, from L.L. puritatem (nom. puritas) "cleanness, pureness," from purus "clean;" cf. Av. pūitika- "serving for purification," Mod.Pers. pâk "clean;" Skt. pavi- "to become clean," pávate "purifies, cleanses;" O.H.G. fouwen, fewen "to sift;" PIE base *peu- "to purify, cleanse."

Nâžâvi "impurity," from nâ- negation prefix, → in-, + žâv "pure" + -i noun suffix.

The condition which exists when two waves of the same frequency pass through their maximum and minimum values in a correlated or synchronized way.

→ in; → phase.

Hamfâz, from ham- "together," → com- + fâz→ phase.

Situated in the natural or original position or place.

From L. in, → in-; L. situ, → site.

Dar "in," → in-; jâ, → place.

1) Prefix meaning "into, in, on, upon, toward, at;" variants im-; il-; ir- by assimilation of -n- with the following consonant. It occurs also sometimes as en, in loans from O.Fr.
2) Prefix meaning "not, opposite of, without."

1) From L. in; cf. Gk. en; P.Gmc. *in (cf. O.Fris, Du., Ger., Goth. in); O.E. in, inne "within."
2) From L. in- "not," cognate with Gk. an-; O.Pers./Av. an-, a- "not, without;" Skt. an-, a- "not;" P.Gmc. *un-; O.E. un-.

1) Dar- "in," from Mid.Pers. andar, → intra-.
2) nâ-, na "not," ma- "not" (prohibitive); Mid.Pers. nê, ma "no, not;" O.Pers. naiy, nai "not;" Av. nôit, naē "not;" cf. Skt. ná "not;" L. ne-, in-, un-; Gk. ni; Lith. nè; O.C.S. ne "not;" PIE *ne-.
bi- privative prefix, from Mid.Pers. abi-, O.Pers. *apaiy-, Av. apa-.
a-, an-, from O.Pers./Av. negation prefix appearing before consonants and vowels respectively. A couple of examples in Mod.Pers.: amordâd "immortality, name of the fifth month in the Iranian calendar," anušé; "fortunate, happy," anirani "non Iranian," âhu "vice, defect," âsoqdé "unburnt, half-burnt wood."

A group to which the speaker, the person spoken of, etc. belongs.

→ in-; → group.

Xodi "insider, familiar, friend," from xod "own," → self-.

The quality or condition of being inaccurate.
The difference between the input quantity applied to a measuring instrument and the output quantity indicated by that instrument. The inaccuracy of an instrument is equal to the sum of its instrument error and its uncertainty.

From negation prefix → in- + → accuracy

1) Not → active.
2) Chem.: Not → reactive.

→ in-; → active.

State of glowing at high → temperature; white or bright-red → heat.

Quality, state noun from → incandescent.

1) (Of light) produced by → incandescence.
2) Glowing or → white with → heat.
3) Intensely → bright; brilliant (Dictionary.com).

From Fr., from L. incandescent-, incandescens, p.p. of incandescere "to become hot," from → in- + candescere "to become hot," from candere "to glow."

Foruzandé, agent noun and verbal adj. from foruzidan, → glow.

Electric lamp in which light is produced by the heating effect of a → metal  → filament.

→ incandescent; → lamp.

1) The degree, extent, or frequency of occurrence, especially of something unwanted.
2) The act of striking a → light ray or → beam of particles on a surface. Also the direction of striking.

M.E., from M.Fr. incidence, from L.L. incidentia, from incidere "to happen, befall," from in- "on" + -cidere, combining form of cadere "to fall," → case.

Fotâd,literally "fall, the act of falling," from fotâdan "to fall," variant of oftâdan "to fall; to happen," → coincide.

Same as → angle of incidence.

→ incidence; → angle.