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

To make something longer or wider by pulling it.

M.E. strecchen, from O.E. streccan; cf. Dan. strække, Sw. sträcka, O.Fris. strekka, O.H.G. strecchan, M.L.G., M.Du., O.H.G., Ger. strecken "to stretch"), perhaps a variant of the root of stark, or from PIE root *strenk- "tight, narrow; pull tight, twist," → strain.

Dargidan, from darg "long" (Zâzâ, Ossetic), variants derâz, derež "long" (→ longitude); Mid.Pers. drâz "long;" O.Pers. darga- "long; " Av. darəga-, darəγa- "long," drājištəm "longest;" cf. Skt. dirghá- "long (in space and time);" PIE *dlonghos- "long."

The second term of the right-hand side in the → induction equation. This term is at the origin of the → dynamo effect and also of the → Alfven waves when in the presence of a mean field.

→ stretch; → term.

The stretching of an object under → tidal force. Tidal stretching results from a difference in the gravitational pull felt on two sides of a body. It is proportional to the inverse cube of the distance to the source of gravity (1/r³). As a consequence, nearby objects, even small ones like the Moon, raise high tides, whereas distant giants like Jupiter do not produce much of an effect.

→ tidal; → stretching.