What-If 0150: "Tatooine Rainbow"

[Farabor]

Great. Now all we have to do is to get it to rain on Tatooine. In the Earthly Tataouine in Tunisia where that part of Star Wars was shot the annual rainfall averages 134 mm. This is nothing like as dry as the Atacama Desert in Chile, with an average rainfall of 15 mm per year. Some locations there average 1 mm of rain per year, and some weather stations in the region have never recorded any rain at all.

This is what I was coming on to wonder about....surprised that of all the details, Randall didn't address the whole dearth of water moisture in Tatooine's atmosphere.

[Agent K]

I just saw an article about a system with 3 stars and an (the-other-kind) orbiting planet:
http://www.cnbc.com/2016/07/08/newly-di ... -seen.html
Now they really should look for an official word for that. Btw, I'm for "intra-tri-solar".

[somitomi]

I suggest that "the other type" be called a Nightfall binary, after Asimov's story.

That would be a strange name, because "nightfall" doesn't happen on such a planet, when it's between the two stars. That being said, I like this name better than "intrabinary" or what-have-you.

[ps.02]

I suggest that "the other type" be called a Nightfall binary, after Asimov's story.

That would be a strange name, because "nightfall" doesn't happen on such a planet, when it's between the two stars.

That's why the classic story is named that: it's set on a planet with a complex orbit involving 6 suns, and the central conceit of the story is the psychological effect of nightfall on a population which has never experienced it.

[pogrmman]

I suggest that "the other type" be called a Nightfall binary, after Asimov's story.

That would be a strange name, because "nightfall" doesn't happen on such a planet, when it's between the two stars. That being said, I like this name better than "intrabinary" or what-have-you.

You should really read the story. It's quite good.
I also think "Nightfall binary" is the best term for this kind of binary. It's concise and immediately gives you an idea for the kind of system it is

[fagricipni]

Today, during/after unsually sharp rain showers, there was a particularly strong primary rainbow and, as well as a secondary bow, the impression of the first bow's violet inner cycling back to green.

Sounds like a case of a supernumerary bow to me.

[Soupspoon]

Today, during/after unsually sharp rain showers, there was a particularly strong primary rainbow and, as well as a secondary bow, the impression of the first bow's violet inner cycling back to green.

Sounds like a case of a supernumerary bow to me.

Possible, but it doesn't have the ripple-effect demonstrated in the linked illustrations. Admitedly they are of a particularly photogenic example.

I frequently see it, but can never get a photograph of it, leading me to consider (but reject, for various reasons) that it is an artefact within my own spectacles, only, or else that it is the colour of magic (not yet rejected, especially given where I last saw the effect... ).

[fagricipni]

Today, during/after unsually sharp rain showers, there was a particularly strong primary rainbow and, as well as a secondary bow, the impression of the first bow's violet inner cycling back to green.

Sounds like a case of a supernumerary bow to me.

Possible, but it doesn't have the ripple-effect demonstrated in the linked illustrations. Admitedly they are of a particularly photogenic example.

I frequently see it ...

I see it frequently in rainbows, too; but with one exception I have never seen more that two "ripples"; there are a number of things can affect the number of supernumeraries that one sees; eg, the distribution of the size of the raindrops: Small raindrops of quite consistent sizes produce the largest number of supernumeraries; a more random distribution of sizes or larger sizes produce less or no supernumeraries.

[RAGBRAIvet]

There is no need to worry about rainbows because there was never much rainfall on Tatooine in the first place.  This is why Luke was first seen with his Uncle Lars and Aunt Beroo on the moisture farm, worrying about the evaporators.

[speising]

I'd assume a "moisture farm" is a place that harvests moisture, such as atmospheric vapor. why then, would that place need evaporators?

[Soupspoon]

I'd assume a "moisture farm" is a place that harvests moisture, such as atmospheric vapor. why then, would that place need evaporators?

They're "vaporators". Think of them like desalinators, that extract the "unsalted" parts of water from water, in that they extract and encistern the vapour (now condensed) from the air.

Or maybe its just misheard/misunderstood terminology retasked as generic science-fantasy technobabble by George "Parsecs" Lucas...

[Oktalist]

A few days ago I saw a rainbow through polarized sunglasses and discovered that rainbows are formed of polarized light. Pretty cool.

With my head tilted at 45°, the top and the two ends of the rainbow were brightest, and the parts in between were dimmest, and the rainbow completely vanished at the two points half way between the top and the horizon. Returning my head to the normal viewing angle, the effect was reversed: the top and ends were dimmer, and the between parts were brighter.

[TvT Rivals]

The photo of the fifth rainbow was very nice, though it was barely visible.