Aliya Summary: G‑d told Noach that he is establishing a covenant to never again bring a flood to destroy the world. G‑d designated the rainbow as the sign of this covenant: “And it shall come to pass, when I cause clouds to come upon the earth, that the rainbow will appear in the cloud. And I will remember My covenant…”
Although rainbows can be explained by science, there’s something so mercurial about them, and that lends itself to help bridge an understanding between G-d and all “flesh”, as the Torah describes it. It’s not something abstract, requires no understanding, it just needs to be seen to be understood. It’s a fickle combination of colors, designed to make us stop what we’re doing, look up, and hopefully remember a covenant that G-d made with us. Of course if G-d wanted to get rid of us there are many other ways, but the point is that we have an unbreakable bond with Him, and the gentle rainbow is meant to remind us of that, so we stop what we’re doing, look up high, and hopefully start thinking even higher.