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

Same as → capillary action.

→ capillary; → -ity.

1) Resembling a strand of hair; hairlike.
2) Pertaining to or occurring in or as if in a tube of fine bore.
3) Physics: Pertaining to → capillarity.
4) Anatomy: One of the minute blood vessels between the terminations of the arteries and the beginnings of the veins (Dictionary.com).

From L. capillaris "pertaining to hair," from capillus "hair."

Muyin, muyiné, from mu(y), → hair.

The ability of a → liquid to → flow in a → narrow space, such as a thin → tube, without the assistance of, and in opposition to, external forces like → gravity. Also called → capillarity. It occurs because of intermolecular → attractive forces between the liquid and solid surrounding surfaces. If the diameter of the tube is sufficiently small, then the combination of → surface tension (which is caused by → cohesion within the liquid) and → adhesion (between the liquid and the → container) acts to lift the liquid. The capillarity of the liquid is high when adhesion is greater than cohesion. For example, water in a thin glass tube has strong → adhesive forces due to the hydrogen bonds that form between the water molecules and the oxygen atoms in the glass wall (made of → silica, SiO₂). In contrast, mercury is characterized by stronger cohesion, and hence its capillarity is much lower.

→ capillary; → action.

An atmospheric optical phenomenon appearing as a vertical shaft of light extending from the Sun or other bright light source during very cold weather. Light pillars or → sun pillars occur when artificial light or sunlight near the horizon is reflected from falling ice crystals associated with thin, high-level clouds. The ice crystals have a hexagonal plate shape and fall with a horizontal orientation, gently rocking from side to side as they fall.

→ light; → pillar.

An elongated structure often found at the interface between an → H II region and its associated → molecular cloud. Also called → elephant trunk. The most famous examples are the "pillars of creation" in the → Eagle Nebula, which are several → light-years in length. There are indications for star formation at the tips of the pillars. In general the pillars point like fingers toward the young → massive stars ionizing the nebula. Most of the mass is concentrated in the head which has a bright rim facing the young stars.

M.E. pillare, O.Fr. piler, from M.L. pilare, from L. pila "pillar, stone barrier."

Sotun "pillar," → column.

→ light pillar.

→ sun; → pillar.