What it means is that The L-rd will never flood the earth again as he did in the old testemant days! It's a G-d thing!
jazzi.... please forgive the slight alteration of the quote. I only did that because it appears as part of this response.
At this point in the Biblical text, G-d establishes His first covenant with all of humanity. G-d pledges that "never again will all flesh be destroyed by a flood," and the sign of this Divine Covenant is indelibly embedded within nature by the formation of the rainbow in the heavens, often appearing in the sky after a rainfall (Genesis 9:11-16).
The 12th-century Biblical commentary by Ramban (Nahmanides) has a striking explanation for the symbol of the rainbow: ancient cultures fought their wars with the bow and arrow, and the side which surrendered, pursuing peace instead of war, would express their will to do so by raising an inverted bow that the enemy could see. Similarly, G-d places an inverted bow in the heavens as a sign that He is no longer warring against humanity. It is as if G-d came to terms with the imperfection of His creation.
In the 19th century, Rabbi Samson Raphael Hirsch suggested an even deeper meaning to the rainbow's symbolism. When we look upon the glorious colors of the rainbow, we are dazzled by the red, orange, yellow, green, blue indigo and violet. In truth, however, these colors only appear to be different hues and shades; they are all light refractions of white, the one true base of all of them. So, too, with the cosmos of humanity; so many peoples of different colors and diverse ethnic backgrounds, all emanating from the "womb" of the one G-d who created them, who all are united by the spark of the Divine which gives them life.
It is Rabbi Hirsch's interpretation that I love deeply.
Karen....I love the precision of science....but a deep part of me turns to and yearns for the beauty of that ancient poetry and all the thought it inspires as well. I see no contradiction for G-d made me as I am, and I love Him for that gift. It was, is and always will be imperfect, but the love that gave it was, is and eternally will be perfect.