Firmament

In ancient near eastern cosmology, the firmament was a celestial barrier that separated the heavenly waters above from the Earth below. In biblical cosmology, the firmament (Hebrew: רָקִ֫יעַ‎ rāqīaʿ) was the vast solid dome created by God during the Genesis creation narrative to separate the primal sea into upper and lower portions so that the dry land could appear.

The concept was adopted into the subsequent Classical and Medieval models of heavenly spheres, but was dropped with advances in astronomy in the 16th and 17th centuries. Today the word is sometimes used as a synonym for the sky or for heaven.

In English, the word "firmament" is recorded as early as 1250, in the Middle English Story of Genesis and Exodus. It later appeared in the King James Bible. The same word is found in French and German Bible translations, all from the Latin firmamentum (a firm object), used in the Vulgate (4th century). This in turn is a calque of the Greek στερέωμᾰ (steréōma), also meaning a solid or firm structure (Greek στερεός = rigid), which appears in the Septuagint, the Greek translation made by Jewish scholars around 200 BC.

These words all translate the Biblical Hebrew word rāqīaʿ (רָקִ֫יעַ‎), used for example in Genesis 1.6, where it is contrasted with shamayim (שָׁמַיִם‎), translated as "heaven(s)" in Genesis 1.1. Rāqīaʿ derives from the root rqʿ (רָקַע‎), meaning "to beat or spread out thinly". The Hebrew lexicographers Brown, Driver and Briggs gloss the noun with "extended surface, (solid) expanse (as if beaten out)" and distinguish two main uses: 1. "(flat) expanse (as if of ice), as base, support", and 2. "the vault of heaven, or 'firmament,' regarded by Hebrews as solid and supporting 'waters' above it." A related noun, riqquaʿ (רִקּוּעַ‎), found in Numbers 16.38 (Hebrew numbering 17.3), refers to the process of hammering metal into sheets. Gerhard von Rad explains:

Rāqīaʿ means that which is firmly hammered, stamped (a word of the same root in Phoenecian means "tin dish"!). The meaning of the verb rqʿ concerns the hammering of the vault of heaven into firmness (Isa. 42.5; Ps.136.6). The Vulgate translates rāqīaʿ with firmamentum, and that remains the best rendering.

— Gerhard von Rad

A firmament is created according to the Enūma Eliš Babylonian creation myth. In the Hebrew Bible, it is mentioned in the Genesis creation narrative, the Psalms, and the Book of Isaiah. Between these two main sources, there is a fundamental agreement in the cosmological models pronounced: this included a flat and likely disk-shaped world with a solid firmament.

The two prominent representations of the firmament were that it was either flat and hovering over the Earth, or that it was a dome and entirely enclosed the Earth's surface. Beyond the firmament is the upper waters, above which further still is the divine abode. The gap between heaven and Earth was bridged by ziggurats and these supported stairways that allowed gods to descend into the Earth from the heavenly realm. A Babylonian clay tablet from the 6th century BC illustrates a world map.