Empyrean vs. Firmament — What's the Difference?

In ancient cosmologies, the Empyrean Heaven, or simply the Empyrean, was the place in the highest heaven, which was supposed to be occupied by the element of fire (or aether in Aristotle's natural philosophy). The word derives from the Medieval Latin empyreus, an adaptation of the Ancient Greek empyros (ἔμπυρος), meaning "in or on the fire (pyr)".The Empyrean was thus used as a name for the firmament, and in Christian literature for the dwelling-place of God, the blessed, celestial beings so divine they are made of pure light, and the source of light and creation.

In biblical cosmology, the firmament is the vast solid dome created by God on the second day to divide the primal sea (called tehom) into upper and lower portions so that the dry land could appear.

The highest reaches of heaven, believed by the ancients to be a realm of pure fire or light.

The vault or expanse of the heavens; the sky.

The abode of God and the angels; paradise.

The vault of the heavens, where the clouds, sun, moon, and stars can be seen; the heavens, the sky.

The sky.

(countable) The field or sphere of an activity or interest.

Of or relating to the empyrean of ancient belief.

In the geocentric Ptolemaic system, the eighth celestial sphere which carried the fixed stars; any celestial sphere.

(historical) The region of pure light and fire; the highest heaven, where the pure element of fire was supposed by the ancients to exist: the same as the ether, the ninth heaven according to ancient astronomy, and Dante's poem.

The abode of God and the angels; heaven.

Of the sky or the heavens; celestially refined.

A piece of jewellery worn in a headdress with numerous gems resembling stars in the sky.

The highest heaven, where the pure element of fire was supposed by the ancients to subsist.

A basis or foundation; a support.

Empyreal.

The act or process of making firm or strengthening.

The apparent surface of the imaginary sphere on which celestial bodies appear to be projected

Fixed foundation; established basis.

Of or relating to the sky or heavens;

The region of the air; the sky or heavens.

Inspiring awe;

The orb of the fixed stars; the most rmote of the celestial spheres.

The apparent surface of the imaginary sphere on which celestial bodies appear to be projected