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

CCD frame with exposure time set to zero and giving the bias level.

→ bias; → frame.

Nurdâd, → exposure; varak→ bias

One of a series of astronomical images obtained using a CCD detector in particular for calibration purposes.

→ CCD; → frame.

A → reference frame that is attached to a moving object. The object in this frame is therefore at rest.

→ comoving; → frame.

1) A border or case for enclosing a picture, mirror, etc.; a structure for admitting or enclosing something.
2) One of the successive pictures on a roll of movie film or videotape.
3) In computers, the information or image on a screen or monitor at any one time.

Frame, from M.E. verb framen "to prepare (timber)," from O.E. framian "to avail, profit."; cf. O.H.G. (gi)framon "to do."

1) Cârcub "frame," from câr, contraction of cahâr "four" (→ four) + cub "stick, satff, beam," Mid.Pers. côp "wood, stick." 2) Tasvirak from Ar. tasvir "image" + -ak suffix of relation and similarity (as in poštak, dastak, nâxonak), → fibril.

The alteration in the → free fall motion of a test → mass in the presence of a massive → rotating object, as compared to the identical case of a non-rotating object. This dragging of → inertial frames is predicted by → general relativity. Also called → Lense-Thirring effect.

→ frame; → drag.

The number of times per second that the frame is scanned in television. Also known as picture frequency.

→ frame; → frequency.

A set of axes to which positions and motions in a system can be referred.

→ frame; → reference.

Same as → inertial reference frame.

→ Galilean; → reference; → frame.

→ inertial reference frame.

→ inertial; → frame.

A → reference frame or coordinate system in which there are no accelerations, only zero or uniform motion in a straight line. According to the special theory of relativity, it is impossible to distinguish between such frames by means of any internal measurement.

→ inertial; → reference; → frame.

A coordinate system or frame of reference defined in the vicinity of the Earth in which Newton's first law of motion is valid; that is, a non-rotating and non-accelerating reference frame.

→ local; → inertial; → time.

A → frame of reference that moves relative to the observer. The moving frame may be → inertial or → non-inertial. See also → rest frame.

→ moving; → frame.

Any frame of reference in which the law of inertia does not apply, such as in accelerating and rotating frames. For example, the Earth is a non-inertial frame because it is rotating about its axis. But the rotation is so slow that the associated acceleration is negligible compared to other accelerations commonly encountered in everyday life. However, the non-inertial nature of the Earth appears in, e.g., the → Coriolis effect. → inertial reference frame.

→ non-; → inertial; → frame.

A set of axes to which positions and motions in a system can be referred. Same as → frame of reference.

→ reference; → frame.

The → frame of reference with respect to which an object or observer is at rest. A clock in that particular rest frame registers what is by definition → proper time. See also → moving frame.

→ rest; → frame.