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

1) Capable of burning, corroding, or destroying living tissue. A caustic substance.
2) Optics: The enveloping surface formed by light rays reflecting or refracting from a curved surface. → caustic curve, → caustic surface.

M.E., from O.Fr. caustique, from L. causticus "burning," from Gk. kaustikos "capable of burning," from kaust(os) "combustible," from kaiein "to burn" + -ikos, → -ic.

Sucân, from suc- "to burn," variant of suz-, suzidan, suxtan "to burn;" cf. Baluci suc-, soc-; Mid.Pers. sôxtan, sôzidan "to burn;" Av. base saoc- "to burn, inflame" sūcā "brilliance," upa.suxta- "inflamed;" cf. Skt. śoc- "to light, glow, burn," śocati "burns," (caus.) socayati, śuc- "flame, glow," śoka- "light, flame;" PIE base *(s)keuk- "to shine."

The intersection of a → caustic surface with a plane passing through the beam of rays.

→ caustic; → curve.

In an → optical system, the → envelope of all the → reflected or → refracted rays (by a → mirror or a → lens respectively) which do not come to a common focal point because of geometrical → aberration. This occurs when parallel rays of light fall on a → concave mirror or when a → convex lens receives parallel light. In the case of → spherical aberration, the caustic surface has an axis of symmetry.

→ caustic; → surface.

The quality of being physically caustic.

→ caustic; → -ity.