> "they have to spiral since they cannot have an end, but since the space is finite, they must coil infinitely at the base."

The moral of the story: in dreams, rainbows are simply-connected.

...anyway, awesome. I would love to be able to produce these on demand in real life. (I guess you can use a garden hose with a spray attachment, but those never give you anything but circles. And they make a mess.)