I am wondering about something that is not astronomical, but it does concern the sky.
As a lector in my parish on 11 January, I read aloud a passage from Isaiah, chapter 55, verses 1 through 11. I became curious about verses 10 and 11, which contain a simile about rainfall.
The Lord is speaking:
Yet just as from the heavens
the rain and snow come down
And do not return there
till they have watered the earth,
making it fertile and fruitful,
Giving seed to the one who sows
and bread to the one who eats,
So shall my word be
that goes forth from my mouth;
It shall not return to me empty,
but shall do what pleases me,
achieving the end for which I sent it.
That water allows plants to grow, and is thus essential to fertility and fruitfulness, is a fact well known to any agricultural civilization.
What caught my eye was the phrase "And do not return there till they have watered the earth." The author appears to believe that water returns to the heavens, and to presume that the reader shares this idea.
This surprised me. Modern hydrology also teaches that water returns to the sky .
But this does not seem to me to be an obvious idea. How did the Hebrews know this?
Thinking further, I realized that, on the topic of what the Hebrews knew about nature, my own knowledge is threadbare. This passage dates from around 550 to 539 B.C., and the words are from the New American Bible. I looked at a couple of other translations and they all share the idea that water returns to the heavens.
What was the Hebrew understanding of rain, snow, evaporation, and the "water cycle" that returns water to the atmosphere?
Did they get it right because their reasoning, in the light of today's science, was correct? Or was it an accident, based on incorrect reasoning that happened to arrive at the answer that water returns to the heavens?
What did other ancient peoples of that time understand about the water cycle?
To get answers, I'll need to find more about the natural philosophy of the Hebrews. There must be learned people who have studied this. Perhaps there are books. Perhaps there is a Web site. Any ideas?