Rainbows in Valinor

[Huinesoron]

I've been coming back to this question again and again, and think I finally have enough of an answer to bring to the Downs:

What would a rainbow look like in Valinor in the Years of the Trees?

To answer this, I've looked at three factors:

1. What would the sky look like? Our sky is blue because sunlight scatters in the atmosphere on the way in, but during the Bliss of Aman the light was coming from inside the atmosphere. My best approximation is that a truly clear sky would be black, but that various atmospheric effects would lead to something more like the light pollution we get from cities - that orange glow on the horizon? So take that and step it up a bit, and you get a bright gold or silver region over the Trees, fading to black at the edges.

As an aside, since the Trees are under the clouds, you don't need any clear skies at all to get a rainbow; so long as the rain isn't so heavy as to physically block the light, you get a rainbow every time.

2. What colours would appear in a rainbow cast by the Trees? Or in other words: which colours were present in Treeslight, and in what quantities?

Gold is the easiest: Laurelin would have given off primarily yellow light, shading into oranges and reds. This is not the same as the Sun, which emits all across the spectrum (and therefore looks white); it's closer to the light you get towards sunset, though I imagine brighter.

As it happens, it's possible to get a rainbow at sunset, often called a red rainbow or monochrome rainbow, and they look something like this:



What about Telperion? Moonlight is actually just reflected sunlight; I think it comes over to us as blue because the blue-light cones in our eyes are more sensitive to low light levels (which is why blue LEDs look so much brighter than red ones). But Telperion had bright silver light, which means we're looking for white light with increased blue levels. I can't share a picture, because actual moonbows are just faint normal rainbows. But you can imagine faint red to green bands, and then a bright, vivid blue on the inner edge. Any double/multiple rainbows would show up as just blue.

3. Where would the rainbows appear? Physics gives the first, simple answer to this: they appear at the far end of a cone with the observer's head at the point, pointing directly away from the light source; and just like here and now, at an angle of 40 degrees from the line between the observer's head and its shadow.

This means that if you were standing under the Trees, you wouldn't see a rainbow at all: it would be down at your feet. You'd have to be at least as far away as the Trees are tall for any part of it to poke above the ground, and if there's anything at all on the horizon you need to go even further.

The Pelori would make it very difficult to see a rainbow in that direction: my feeling is that they're probably tall enough to interfere with any possible rainbow. The exception would be down the Pass of Light; you would be able to see a gold or silver bow arching beautifully over Tirion. To the north, south, and west, the horizon is lower down, so you'd see them most of the time, always directly opposite the Trees.

But there's a catch: sunlight comes into our atmosphere basically parallel, which is why you get a single cohesive rainbow. With the Trees being much closer, you'd get a lot more scattering of the light - it would all be hitting the raindrops at different angles, and bouncing back to form different cones. So rather than one rainbow, I think you'd get an overlapping, shifting curtain of them, covering a section of the sky.

... which ironically might make them look a bit more like a (tied) bow, with a pinched section in the middle where the flat portions of the arches overlap, and broad falls of light on either side.

This effect would only be doubled when both Trees were shining: Laurelin and Telperion would cast their light at slightly different angles, so their rainbows would be offset but overlapping. You'd have a bright blue bow cutting across a red-gold one, with the mingled light casting green and purple highlights everywhere.

This is, to say the least, very difficult to visualise, but I've made an effort:



I think the real thing would look, y'know, actually pretty... I'm not all that confident on the physics, though, so if there's anyone who actually knows anything about rainbows - or anyone else who wants to read Wikipedia about it - I'd love to hear your thoughts on what it would look like.

hS