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False colour July 15, 2017

Posted by WorldbyStorm in Uncategorized.
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This is a good piece on the colours of the planets. This is a real bugbear of mine, the fact that so much space photography is artificial, in that it does not depict what we can see with our own eyes. Particularly egregious are photographs of star fields and nebulas. In reality the latter would tend to appear like diffuse somewhat luminous areas rather than the highly colourful visuals we see both on television in SF but also in photographs from Hubble etc.

This piece notes that:

But a camera on a spacecraft rarely sees colours in the same way as the human eye. For example, the red, green and blue components are usually recorded separately, transmitted to Earth as three separate black-and-white images and combined in colour only for display purposes. How the colours come out is bound to be at least subtly different from the ways your eyes would perceive the same view.
What’s more, the colours on an image don’t necessarily correspond to the original colours, even if there has been no attempt to exaggerate them. In principle, a spacecraft camera can record in any part of the light spectrum. When one of the channels lies beyond the visible range, such as in ultraviolet, we still have to use either red, green or blue to display it. That means the resulting picture is “false colour”, which might then be further exaggerated.

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1. Dermot O Connor - July 15, 2017

Raises the philosophical question of qualia (the perception of colors by the brain). The brain creates the colors ‘red’ ‘orange’ ‘yellow’ etc. mapping them onto different wavelengthes, in that sense, the colours we see in our minds are ‘false’, or constructed (zen koan: “who is the great lord who makes the grass green?”)

There is no way of knowing how an alien species would perceive the same objects (the ‘inverted spectrum argument’); their eyes / minds would likely see in wider/different range of the spectrum; seems unlikely that they would share our colour values.

Mind you, NASA does the same chicanery with the aspect ratios when they do the computer flyovers of surfaces; they scale up the vertical aspect ratio by very high factors, something like 10X, in order for the landscape to ‘read’.

I recall reading that the famous space-painter Chesley Bonestell was bitterly disappointed with the actual photos from the moon, as they fell so far short of his imagination. He was right; his photos, with steep craggy peaks and crevasses, are fantastic. The actual moon is more like the English downs without grass, trees, or anything that might threaten to make them interesting.

Sad to think that the universe is flatter and duller than we like to imagine. This is one reason why I admired the portrayal in BSG (reboot), vast, bland and gray. The designers on that show got this; the idea that the best place in the universe is this one. It really is astonishing that so many fanboys ever liked that show, because it was a massive FU to the Elon Musks of this world.

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WorldbyStorm - July 15, 2017

Great point re the exaggeration of the vertical aspect. It’s like OLympus Mons on Mars, it’s so big one probably couldn’t get a sense of its scale if there but a lot of depictions accentuate the vertical for effect.

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Dermot O Connor - July 15, 2017

Same with Mariner Valley, they have to drop the floor down by 10x. In reality, from one end of the canyon you’d never see the other side; from the ground, probably not as impressive as the much smaller Grand Canyon on Earth.

I wish they’d send some of their rovers to the more impressive spots visually, like the Canyon, to find out for sure, but those NASA bastards aren’t sufficiently motivated by aesthetics, damn them.

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WorldbyStorm - July 15, 2017

+1 it’s not that they don’t get it but as you say not sufficiently.

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2. Robert - July 17, 2017

So the moon is boring and light-year long pillars of hydrogen aren’t green. That’s my evening ruined.

In bemoaning the false colouring you are, I think, missing the point; the object of the exercise is to show what’s there, and the colouring is to make it look pretty. In both of these, the hubble (et al) images succeed spectacularly, to my mind. In each case NASA or the STSCI make clear what sort of trickery (not chicanery) is used to illustrate the point and the colours are often used to show different temperatures, gasses, whatever, and are done so in a manner that NASA think we’ll all find aesthetically pleasing. They’re not wrong. And ESA even provide funky animations to show how the images of different telescopes (typically IR, X-ray and visible) are combined to give a more complete picture. I’ve never been under any illusion that what I’m seeing is the same thing that I’d see if I happened to be passing on my way to the shops; nor has anyone tried to misrepresent it as such.

Equally, I’m more than familiar with the ‘heights have been magnified 10x’ disclaimer at the bottom of videos and/or images.

If we don’t get such tricks, we’d end up with some deeply boring images. The Eagle nebula is one of the second only to the Hubble Deep Field in terms of spectacularity (probably not a word), and I for one am supremely grateful to NASA and the artist who chose the colouring for the effort that went into it.

We all want accuracy and faithful representations of what’s there. But if our eyes can’t reveal the universe in all its variety, I for one am glad that ESA and NASA are giving us a helping hand. Or rod. Or cone.

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WorldbyStorm - July 17, 2017

I don’t know if I’m bemoaning it as much as just feeling s bit sad about it. Ive a good pair if binoculars and there’s little as fascinating as studying the moon or the Jovian system or the stars and I’m very much in favour of NASA and ESAs promotional work. But the problem isn’t with them really or the universe as it is with us and our eyes.

Im a huge fan of space art and there’s a fantastic book David Hardy illustrated for Patrick Moore in 1970 or so. Amongst the paintings is one if a planet circling a star outside the galaxy and the galaxy high in the night sky. But we as humans wouldn’t see such a splendid sight, it would probably be very diffuse.

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3. Joe - July 17, 2017

“Raises the philosophical question of qualia (the perception of colors by the brain). The brain creates the colors ‘red’ ‘orange’ ‘yellow’ etc. mapping them onto different wavelengthes, in that sense, the colours we see in our minds are ‘false’, or constructed (zen koan: “who is the great lord who makes the grass green?”)”

And then there’s the fascinating topic of colours and how they are understood in different languages and cultures. Which I must research a bit more before I make some half-imagined, half-understood comment!

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WorldbyStorm - July 17, 2017

Thats something I hadn’t thought if Joe. I can see how languages would reflect all the issues raised above. Just in Irish are there distinct differences or shades from English?

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Joe - July 17, 2017

I’m not expert enough to answer that. But I know (I think) that ‘glas’ in Irish can be translated as green or grey. But I’m guessing with the dominance of English in the world, other languages are changing to conform to the English norm. I read somewhere that in some African languages there were only three or four ‘colour’ words.
Colours are a spectrum aren’t they? So, in the English language, the word blue describes a piece of that spectrum – but where does blue stop and green start. I had a car once that was blue but everyone else saw it as green.

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EWI - July 17, 2017

Wasn’t it the case that there weren’t separate words for blue and green in Irish? Similar state of affairs for other languages, too.

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Joe - July 17, 2017

Could be. In school we learned gorm for blue and glas for green. Then there’s uaithne for green too. In school ‘fear gorm’ was a black man, now it’s ‘fear dubh’.

Here’s a wiki piece on it. Many on here will be excited to see that some cultures don’t recognise the orange :). https://en.wikipedia.org/wiki/List_of_colors_in_various_languages

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Joe - July 17, 2017

That wiki piece says the Irish for orange is flannbhuí. I would have said oráiste.

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WorldbyStorm - July 17, 2017

Hah, don’t let Roddy hear us discussing this! Always loved orange as a colour. I heard a podcast some years back which suggested the Greeks used red for blue – something to do with blue being less apparent in nature,though I forget details. Doesn’t quite make sense to me but I’m sure I’m getting it wrong

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sonofstan - July 17, 2017

” I heard a podcast some years back which suggested the Greeks used red for blue”

Hence Homer and his wine-dark sea?

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WorldbyStorm - July 17, 2017

Yes that was part of it. This touches on it. Fascinating stuff.
http://www.abc.net.au/radionational/programs/bodysphere/features/5267698

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RosencrantzisDead - July 17, 2017

The colour ‘orange’, in Europe at least, only appeared after the discovery of the fruit. Before then the hue would often be conflated with red. Hence robin having a ‘red breast’ despite the colour being a very striking orange.

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The last Trump - July 17, 2017

There’s an Austrian seagull tamer fom little Killary who would like to have a word with you lot.

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