The word circle in Hebrew, khug, is best translated in terms of sphericity or roundness.
But if you are implying that the authors of the Bible made stuff up as they went along based upon new scientific discoveries – explain the Star of Bethlehem…
It appears a group of ancient scientists made an important discovery.
I went to this site:
http://www.breslov.com/ref/Isaiah40.htm
which has the bible in Hebrew and English. The English translation of Isaiah 40:22 is this:
It is He that sitteth above the circle of the earth, and the inhabitants thereof are as grasshoppers; that stretcheth out the heavens as a curtain, and spreadeth them out as a tent to dwell in;The site has a Hebrew-Engish dictionary. "Circle" in English gives this in Hebrew: gwx. Transliterated (whatever that means) it's Chuwg, which is what you gave. The definition (for both, presumably) is given as: 1. circle, circuit, compass; 2. (BDB) vault (of the heavens)
The same word is in Proverbs 8:27. When he prepared the heavens, I was there: when he set a compass upon the face of the depth.
And in Job 22:14. Thick clouds are a covering to him, that he seeth not; and he walketh in the circuit of heaven.
I am no bible scholar (obviously) but I see no hint of "sphericity" in any of these uses of the term.