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

Of or relating to inertia.

From → inertia + → -al.

Laxt, adj. of laxti, → inertia

A force arising from the → acceleration of an observer's → frame of reference.

→ inertial; → force.

→ inertial reference frame.

→ inertial; → frame.

The mass of a body as determined from the acceleration of the body when it is subjected to a force that is not due to gravity.

→ inertial; → mass.

Motion free of any force, with constant velocity.

→ inertial; → motion.

1) A periodic motion of a particle that moves, free from external forces, over the surface of a rotating sphere, such the Earth. Inertial oscillations result from the → Coriolis force. For example, a hockey puck launched on a big enough lake in the northern hemisphere would turn to the right (east) and eventually loop back to nearly the initial point (actually west of that point). The time it takes for the huckey puck to return can be computed with the → Coriolis frequency.
2) Meteo.: An anticyclonic (clockwise) rotation in the northern hemisphere, with the Coriolis force providing the → centripetal acceleration with period of 2π/f, where f is the Coriolis frequency. The opposite should occur in the southern hemisphere.

→ inertial; → oscillation.

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.

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.