An Etymological Dictionary of Astronomy and Astrophysics
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Physics: Of an atom, molecule, collection of particles, having no net charge; not electrified.
Chemistry: Exhibiting neither acid nor alkaline qualities.

From → neuter + → -al.

→ neuter.

An atom in which the number of → protons equals the number of → electrons and therefore has no net → electric charge.

→ neutral; → atom.

A filter having a flat response over the range of wavelengths of interest. Also called neutral filter or gray filter.

→ neutral; → density; → filter.

Same as → neutral density filter.

→ neutral; → filter.

A gas which is not ionized.

→ neutral; → gas.

Non-ionized → atomic hydrogen gas which constitutes an important component of the → interstellar medium, accounting for perhaps half its mass, even though its density is very low. Its radio emission → 21-centimeter line has made it possible to map the distribution of neutral hydrogen in the → spiral arms of our own Galaxy and other nearby galaxies.

→ neutral; → hydrogen.

In hydrodynamic instability theory, a wave solution the amplitude of which does not change with time; it neither grows nor decays. Also called neutral wave.

→ neutral; → mode.

1) A point where two fields are equal in magnitude and opposite in direction so that the net force exerted on it is zero.
2) One of several points in the sky for which the → degree of polarization of diffuse sky light is zero.

→ neutral; → point.

Same as → sodium tail.

→ neutral; → tail.

Same as → neutral mode.

→ neutral; → wave.

A hypothetical particle predicted by supersymmetry theories, which aim at relating bosons to fermions. Under certain assumptions, the lightest such partner particle would be stable, and if it is neutral (a "neutralino"), would make a good dark matter candidate. Reasonable neutralino masses range from 30 GeV to 10 TeV.

From → neutral + -ino diminutive suffix.

In optics, the process of combining two lenses having equal and opposite powers to produce a result having no power.

Verbal noun of → neutralize.

To make neutral; cause to undergo neutralization.
To render electrically or magnetically neutral.

Infinitive from → neutral.