Until about the time of Sir Isaac Newton (1642-1727) [See biography], Christian scholars understood the firmament of the Bible as depicting the rigid sky, which revolved around the earth once each day, carrying along all the stars. This assumed motion of the sky reflected the common-sense notion that the earth was stationary. For the stars to move in a manner consistent with observation, they had to be held fixed in their relative positions. The stars seemed to trace partial circles around the poles each night. Their movements appeared exactly as if they were fixed on the underside of a great revolving dome, or the inner surface of a sphere. This belief in a rigid sphere of heaven gave rise to the expression "the sphere of the fixed stars."
The planetary motions did not conform to this explanation, and it was the detailed study of the orbits of the planets by Johannes Kepler, his discovery of the elliptical form of the orbit of Mars, and Newton's interpretation of Kepler's discoveries, which led to the recognition of the law of gravity, and the abandonment of the idea of a rigid rotating firmament.
The apparent absurdity of the scriptural references to a rigid heavenly firmament and "waters above the heavens" has been exploited by humorists as an object of ridicule. Dietz and Holden include an account of the cosmology of scripture in their Creation/Evolution Satiricon. They claim the biblical earth is flat, and state: "The Genesis creation story tells that the earth is covered by a vault and that celestial bodies move inside this firmament. This makes sense only under the assumption that the earth is flat."
Along with their account, two cartoons depict the earth and the universe as they suppose the ancient authors of scripture believed it to be. A curious feature of these drawings is that the waters beneath the earth seem to conflict with the concept of fires of hell. These waters are shown in the cartoons being held up in a kind of sheet by two angels in one picture, and by two demons in the other, above the subterranean fires, over which Satan presides. The waters beneath the earth's crust seem to be about to put out the subterranean fires. The biblical universe, as they picture it, would have three water layers, one above the heavens, the next being the oceans and lakes of the world, and the third consisting of the waters beneath the earth. They wrote [p.65]:
While priests found it relatively easy to ignore the flat-earth implications in the Bible and to adopt the spherical system of Ptolemy, they were rudely shaken by Copernicus and Galileo. Galileo, of course, was arraigned before the Catholic Inquisition and forced to recant his heretical view that the earth rotated and also revolved around the sun. For scriptural reasons other early Protestant reformers also rejected the Copernican system. These included Luther, Calvin and Wesley. Some Protestant creationists are still fighting a rear-guard action against heliocentricity.
[For an example, see Introduction to the Firmament.]
[See also The Geocentricity Question.]
Dietz and Holden continue:
Biblically, the earth is arched over with a solid firmament (Genesis 1:7). Isaiah and the Psalms state the heavens are stretched out "like a curtain" and again "like a tent to dwell in." The universe, then, resembles a simple house with the earth as the ground floor and the firmament as the ceiling beneath which God suspends the sun to rule the day and the moon and stars to rule the night. Waters or seas lie both above the firmament and beneath and surrounding the square or rectangular earth. Waters are let down upon the earth by the Lord and his angels through the "windows of heaven." Water also ascends to the earth through the "fountains of the deep." St. Augustine said it mattered little whether the celestial dome rested on pillars or hung over the edges of the earth.
Dietz and Holden describe the ideas of the 6th century AD Egyptian monk, Cosmas Indicopleustes, who believed in a flat earth. They quote his statement: "We say therefore with Isaiah that the heaven embracing the earth is a vault, with Job that it is joined to the earth, and with Moses that its length is greater than its breadth." They quote Genesis 1:6-10 from the New American Bible, which has: "Then God said, 'Let there be a dome in the middle of the waters to separate one body of water from another.' And so it happened... God called the dome 'the sky.'..." The authors continue:
Envisioned in this pre-scientific account is a flat terrestrial plain over which is erected the great crystalline firmament or the dome of the sky. Water not only partially covered the earth but also formed a vast reservoir above the dome. And why not? This model accounted nicely for rainfall and explained why the sky is blue-the colour of pure water.
In the ancient biblical view the universe was three storied. It consisted of the cavernous underground of Hades or Hell, the flat earth proper, and the sky-dome beneath which were attached the sun, moon and stars. It was quite natural to believe that stars fell from time to time and that there was a real danger of the sky itself falling. These themes occur throughout the Bible. (There follows a list of scriptures.)
A similar approach to the firmament of scripture was adopted by Paul H. Seely. While affirming scripture was divinely inspired, Seely pointed to statements of Jesus and the prophets of the Old Testament which seem to indicate the stars were small and could fall from the firmament to the earth, and suggested that Jesus' statement in Matthew 5:45 that God "makes his sun to rise" shows Jesus believed in a geocentric universe. According to Seely, "the Bible portrays a three-storied universe, a cosmology which any modern man will reject as being scientifically erroneous." He wrote [Seely 1969, p. 18]:
The three-storied universe is a cosmology wherein the universe is conceived of as consisting of three stories. The ceiling of Sheol, the bottom story, is the surface of the earth. The surface of the earth, in turn, is the floor of the middle story. The ceiling of the middle story is the firmament with its contiguous heavenly ocean. This firmament with its ocean is, in turn, the floor of the top story, heaven.
Dietz and Holden pictured Biblical cosmology in this fashion for a joke, but Seely was not joking. A rebuttal to Seely's argument was made by Stanley Udd, who defended a canopy theory in which liquid water is supposed to have formerly existed above the earth's atmosphere. He described the interpretation of the biblical firmament by Seely and other scholars:
Such critics contend that the Genesis narrative reflects an early Hebrew understanding of cosmology in which the sky was over-arched by a ponderous, hemispheric bell called the "firmament." This supposed vault supported the "waters above the firmament" and was equipped with trap-doors through which rain might descend. From this imagined structure were then hung the sun, moon, and stars on the fourth day of creation.
The firmament was commonly depicted in medieval religious art as an arc or dome above which God and the angels resided. It was also represented by domes on churches and mosques. The origins of this concept, however, belong not in the scripture, but in the philosophy and epic poetry of the Greeks, as this report explains.
See also these papers by Paul Seely: The Firmament and the Water Above Part I: The Meaning of raqiaà in Gen 1:6-8, from the Westminster Theological Journal 53 (Fall 1991) 241-261, and The Firmament and the Water Above Part II: The Meaning of "The Water above the Firmament" in Gen 1:6-8, Westminster Theological Journal 94 (1992) 47-63.