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

In plasma physics, the theory that considers the interactions between waves and particles are of first order only. It ignores all terms of second order in the fluctuating quantities.

→ quasi-; → linear; → theory.

In a straight line; consisting of straight lines. → curvilinear

From recti- combining form of rectus, → right, + → line + -ar, variant of the adjective-forming suffix → -al.

Râst-xatt, from râst, → right, + xatt→ line.

The motion of light in the first approximation, as evidenced from the formation of shadows and other every day experience. However, → diffraction

→ rectilinear; → propagation; → light.

An optical system that is corrected for → distortion and → spherical aberration and therefore forms the image of a straight line as a straight line.

→ rectilinear; → system.