An Etymological Dictionary of Astronomy and Astrophysics
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→ Dark matter composed of → non-baryonic particles.

→ non-; → baryonic; → dark; → matter.

Matter that, unlike the ordinary matter, is not made of baryons (including the neutrons and protons). It is proposed as a possible constituent of dark matter.

→ non-; → baryonic matter.

Radiation having waves that are out of phase in space and/or time; radiation which is not → coherent.

→ non-; → coherent; → radiation.

Describing a → proposition that is either → true in every possible circumstance or → false in every possible circumstance. A proposition that is not → contingent.

→ non-; → contingent.

A medium in which the → phase velocity is independent of frequency.

→ non-; → dispersive; → medium.

Any of several geometries which do not follow the postulates and results of Euclidean geometry. For example, in a non-Euclidean geometry through a point several lines can be drawn parallel to another line. Or, the sum of the interior angles of a triangle differs from 180 degrees. According to Einstein's general relativity theory, gravity distorts space into a non-Euclidean geometry.

→ non-; → Euclidean geometry.

A → multiple star system that lacks the characteristics of a → hierarchical multiple system.

→ non-; → hierarchical; → multiple; → system.

A → magnetohydrodynamics approach dealing with → plasmas which is an improvement with respect to → ideal magnetohydrodynamics. Non-ideal magnetohydrodynamics allows for a drift between particles, redistributing the → magnetic flux and acting on both the → angular momentum and magnetic flux conservation issues.

→ non-→ ideal; → magnetohydrodynamics.

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.

Not ionized, → neutral.

→ non-; → ionized.

A physical condition in which the assumption of the → local thermodynamic equilibrium does not hold.

→ non-; → local thermodynamic equilibrium.

Not ordinary matter. Same as → dark matter.

→ non-; → luminous; → matter.

A → tumbling motion of an → asteroid. See also → tumbling asteroid.

→ non-; → principal axis; → rotational; → motion.

A type of stellar pulsation in which waves run in different directions on and beneath the surface of a star.

→ non-; → radial; → pulsation.

An process in which an excited state returns to the ground state without emitting radiation. → radiative process.

→ non-; → radiative; → process.

Not concerned with or based on the → theory of relativity. See also:
→ non-relativistic electron, → non-relativistic mechanics, → relativistic.

→ non-; → relativistic.

An electron that does not experience relativistic effects since its velocity is very small compared to that of light.

→ non-relativistic; → electron.

Mechanics in which the masses under consideration move at speeds much slower than the speed of light.

→ non-relativistic; → mechanics.

The nature of a → non-thermal radiation.

→ non-; → thermal.

→ non-thermal radiation.

→ non-thermal; → emission.