Problem: Job speaks of God who “spread out the skies” like “a cast metal mirror” (37:18). Indeed, the Hebrew word for the “firmament” (raqia) which God created (cf. Gen. 1:6) is defined in the Hebrew lexicon as a solid object. But this is in clear conflict with the modern scientific understanding of space as non-solid and largely empty.
Solution: It is true that the origin of the Hebrew word raqia meant a solid object. However, meaning is not determined by origin (etymology), but by usage. Originally, the English word “board” referred to a wooden plank. But when we speak of a church board member, the word no longer has that meaning. When used of the atmosphere above the earth, “firmament” clearly does not mean something solid. This is evident for several reasons. First, the related word raqa (beat out, spread out) is correctly rendered “expanse” by many recent translations. Just as metal spreads out when beaten (cf. Ex. 39:3; Isa. 40:19), so the firmament is a thinned out area.
Second, the root meaning “spread out” can be used independently of “beat out,” as it is in several passages (cf. Ps. 136:6; Isa. 42:5; 44:24). Isaiah wrote, “So says Jehovah God, He who created the heavens and stretched them out, spreading out the earth and its offspring (Isa. 42:5, mkjv). This same verb is used of extending curtains or tents in which to dwell, which would make no sense if there was no empty space there in which to live. Isaiah, for example, spoke of the Lord “who sits on the circle of the earth, and its people are like grasshoppers; who stretches out the heavens like a curtain, and spreads them out like a tent to dwell in …” (Isa. 40:22, mkjv).
Third, the Bible speaks of rain falling through the sky (Job 36:27–28). But this makes no sense if the sky is a metal dome. Nowhere does the Bible refer to little holes in a metal dome through which the drops fall. It does speak figuratively of the “windows of heaven” opening for the Flood (Gen. 7:11). But this should probably not be taken any more literally than our idiom, “It is raining cats and dogs.”
Fourth, the Genesis creation account speaks of birds that “fly above the earth across the face of the firmament” (Gen. 1:20). But this would be impossible if the sky was solid. Thus, it is more appropriate to translate raqia by the word “expanse” (as the nasb and niv do). And in this sense there is no conflict with the concept of space in modern science.
Fifth, even taken literally, Job’s statement (37:18) does not affirm that the “skies” are a “metal mirror,” but simply that they are “as [like]” a mirror. In other words, it is a comparison that need not be taken literally, any more than God is really a “strong tower” (cf. Prov. 18:10). Further, the point of comparison in Job is not the solidity of the “skies” and a mirror, but their durability (cf. word “strong” [chazaq]; v. 18). So when all is considered, there is no evidence that the Bible affirms that the firmament of the sky is a metallic dome. And thus there is no conflict with modern science.