Though partly tongue-in-cheek and meant to convey a humorous little insight I occasionally chuckle at, there is an element of seriousness behind today’s question. Simply put: if water covers over 70% of Earth’s surface to this day, what are we to make of the skeptic’s demand for “evidence” of a worldwide deluge? I can’t help but return to the humorous proposition implied in Asteroids, Cathode Rays and Requisite Knowledge, wherein a skeptic standing in Tin Bider mocks Aristotle’s hypothetical claim about “huge, flying rocks in space.”
Today's post is just a quick one for the physics and optics students out there, who are welcomed to freely speculate. Actually, everyone is freely welcomed to speculate! Also, I'd really appreciate any links to people, websites or books that can provide useful information, so if anything comes to mind, by all means share!
I'm trying to get some kind of consensus on a recurring question I've got. We perceive rainbows because of a neat little process called chromatic dispersion by which white light refracts through water droplets in the atmosphere. The white light actually refracts twice: once upon entrance which separates the light into its constituent colors, and again upon exit which amplifies this separation. When a terrestrial observer sees a rainbow in Earth's atmosphere, what they're really seeing is the separation of incoming white sunlight into the familiar colors of the rainbow: red, orange, yellow, green, blue, indigo and violet.
My question is: if Earth were enveloped by a "shell" of solid water, would this affect the rainbow-creating process? Would terrestrial observers on Earth still be able to see rainbows?