I like to point out that we are blind to the extraordinarily common "colors" of nitrogen gas and water vapor, blindness which is beneficial, because otherwise we'd constantly stumble through fog until we go over the edge of a cliff or get eaten by a tiger.
Yet if some aliens insisted that our planet was a very boring featureless nitrogen-colored ball, we would probably object that their viewing strategy is naive and incorrect.
We are born seeing the universe based on pragmatic decisions about signal versus noise. Our evolved tuning utterly fails in new places, so we should pick new tunings.
gchamonlive 30 days ago [-]
Rather than new tunings, they are more like tune mapping, from one possible set of fitness functions to our set of fitness functions.
And I'd argue that it's all signal. Noise is something very human -- maybe even for carbon-based lifeforms, but I'd be careful to make such broad assertion --, that which is unnecessary or harmful for the needs of the body.
Vox_Leone 33 days ago [-]
To the unaided human eye, space is largely a muted void. Stars pierce through the darkness like pinholes in velvet, but much of the grand tapestry—the swirling colors of nebulae, the fiery birthplaces of stars, the delicate filaments of distant galaxies—are invisible. Our vision, evolved for survival under a sunlit sky and on a green-blue Earth, isn’t tuned to perceive the vast electromagnetic chorus the universe sings in.
Although space may appear subdued to our eyes, that doesn’t mean it isn’t beautiful—only that we need to borrow better eyes to truly see it
pestatije 33 days ago [-]
Images are not real, whether astronomical or not...the colours coming from your display or printout have a very different spectrum from that of the real object
gchamonlive 30 days ago [-]
The image you see is also very different from the images that hit your eyes, since they travel through complicated mechanisms before being consciously assimilated by the mind, but at this point what are we even talking about...
Etheryte 30 days ago [-]
Ceci n'est pas un commentaire.
gherard5555 30 days ago [-]
Ceci n'est pas une réponse
kunzhi 30 days ago [-]
Ceci n'est pas une pipe
kelseydh 30 days ago [-]
A bit of a tangent, but this excerpt from a Sam Kriss rant about science content on social media always stuck with me:
Those multicoloured nebulae are not real objects, they exist only in fantastic pictures overlaid with Neil deGrasse Tyson’s face and some vague sentiments about how wonderful the universe is when it’s very far away from human life. The images are digitally stitched together, the colours are fake, the shapes are not anything that could actually be seen out the window of your spaceship, a real-life nebula is about as exciting as a damp fog.
There is a wonderful book about this very thing: “Picturing the Cosmos:
Hubble Space Telescope Images and the Astronomical Sublime” — from the description: “Elizabeth A. Kessler examines the Hubble’s deep space images, highlighting the remarkable resemblance they bear to nineteenth-century paintings and photographs of the American West and their invocation of the visual language of the sublime.” https://www.upress.umn.edu/9780816679577/picturing-the-cosmo...
godshatter 30 days ago [-]
I've seen the sun described as being really mostly white and that the yellow color we normally see has more to do with what light makes it through the atmosphere rather than the actual color of the star and that the light is a continuous spectrum and so on. But then the sun is also classified as a G-2, a yellow dwarf. Is the color that we see in the sky just coincidentally match the color the star is classified under?
adrian_b 29 days ago [-]
The yellow implied in "G-2" is just a convention, it has nothing to do with the real color (as seen outside the atmosphere; on the surface of the Earth all white stars are seen as yellowish).
Color temperatures in the range of 5000 K to 7000 K, where the "yellow" stars belong, are all seen as pretty pure white, with the range of 5500 K to 6000 K, like the Sun, as the whitest. Even a colder star at 4000 K is only very slightly yellowish. Going to lower temperatures, e.g. 3000 K or less, the color becomes definitely yellow, then orange, then red.
You can verify this by looking at lamps with specified color temperatures, to see what color they seem to have for you.
The Sun seen from the Earth is seen as yellowish at noon and as reddish at sunset and at dawn because of the low-pass filter effect of the atmosphere, which removes the blue light from the direct light of the Sun and spreads it over the sky. When the blue sky light and the direct yellowish Sun light are mixed again, like in clouds, you see white light, thus the clouds are white, which is the real color of the Sun. On the Moon, without atmosphere, the Sun would be white.
Going towards higher temperatures, the white stars become blue-green, then blue. There are no green-emitting black bodies.
godshatter 28 days ago [-]
Thank you, that's very helpful.
on_the_train 30 days ago [-]
That sounds a lot like dodging the question. Obviously correcting for things like red shifts, camera limitations etc is fine. But as far as I know there are many instances where the coloring is pushed beyond anything remotely realistic. I think the pillars of creation are a popular example
creatonez 30 days ago [-]
Keep in mind that Pillars of Creation is not supposed to be intentionally beautiful. It's a false color image for maximizing research value. Green for hydrogen band, red for sulfur band, blue for oxygen band. The goal of the processing is to minimize the error in these three readings, to study the ionized gas in the cloud as it truly is. If it were engineered for the public to look in awe, you could probably come up with an even more striking coloring than a simple RGB assignment. This is something a lot of people get wrong about the topic of false color images -- usually, there is not a separate "for the public" and "for researchers" image. The media outlets just pulled the coolest looking processed images out of actual research papers, and some of them were so cool looking they became cultural icons. (The exceptions to this, ironically, are when an image is intentionally processed to be as close to true color as possible -- which makes it less useful for research purposes, but fantastic for writing explainers for laymen on the topic of false color images.)
Though, you could say it's indirectly designed for beauty. When astronomers process an image, they are looking for interesting features to study. And once you've narrowed in on the most scientifically interesting way to process an image, the sorts of striking color contrasts that creates are inherently beautiful because they are unveiling the interesting parts & letting us see the unseen for the first time. And there is selection bias on what is interesting to look at. A violent explosion is both more aesthetically inspiring and teaches us more about how matter works than a picture of a random stairwell, and astronomers love their violent explosions.
DiogenesKynikos 30 days ago [-]
Astronomers rarely look at color images. These color images are produced by press offices for the public.
That being said, the complaint that the images are "unrealistic" are off-base. The images accurately portray the information that was captured by the telescope. Your eyes often can't even see the wavelengths imaged by space telescopes (like the James Webb Space Telescope), so how you map those wavelengths to RGB is largely arbitrary. As long as you map them in the same order (shorter wavelengths appear bluer, longer wavelengths appear redder), I would consider the images accurate.
creatonez 30 days ago [-]
This is just not true, though. Astronomers look at color images all the time, in certain areas of research at least. Many color images in the media are copied directly from research papers, since image processing can be rather labor intense to be done just for PR purposes (mainly because you have to essentially calibrate the positioning and noise characteristics of the sensors from scratch -- the color assignment part can actually be done in vanilla photoshop). This is something I feel the article skipped out on explaining, that these false color images are actually research tools the same way that the grayscale images are.
It is true that they also look at a lot of grayscale images, though. Differentiating chemicals in nebulas or on the surface of planets isn't always necessary, and you can always take the simpler (but sometimes less useful, since it doesn't make full use of the human visual system) route of looking at multiple grayscale images. A lot of the areas where false color is most useful are well-trodded ground, so we don't necessarily need more images of the same objects when the existing body of research is already rich. And sometimes, a researcher includes an image in their paper just because they thought it looked cool, not because it was useful for the methodology.
DiogenesKynikos 29 days ago [-]
Astronomers almost exclusively look at grayscale images (sometimes with an applied colormap, but the underlying data is still just a single channel) when doing actual work.
There are some rare cases in which an audible might look at a color image, but the overwhelming majority of images astronomers deal with daily are grayscale.
xioxox 30 days ago [-]
That's not right. I'm an astronomer, and I often look at colour images and colleagues do, too. For example, the galaxies in a cluster of galaxies follow a relation of colours - brightness (the "red sequence"), which can be used to detect the cluster. The eye is also quite good at helping confirm a cluster by spotting the galaxies following this sequence. I also use colour images to help identify spectral changes that change across an image, in my case in the X-ray waveband.
DiogenesKynikos 29 days ago [-]
Most astronomers look at the red sequence on a scatterplot, with each point being based on the measured fluxes of one galaxy. Very few astronomers are literally looking at color images to eyeball these measurements.
There are edge cases in which astronomers will load up images at multiple wavelengths and overlay them, but this is not the normal case. By and large, they're looking at a single channel at a time. Even more commonly than that, they're working with catalogs automatically generated from images.
xioxox 17 days ago [-]
You are plainly wrong. I know several astronomers who look at colour images to check that the software is working properly.
DiogenesKynikos 17 days ago [-]
"Several" out of how many? This just isn't common in astronomy, outside of public outreach.
on_the_train 30 days ago [-]
Color Images imply that they are real colors. If they are not, that's misleading.
DiogenesKynikos 29 days ago [-]
There are real colors. Your eyes are just incapable of seeing them.
Would you rather thaw NASA show you a blank image and say, "This is our newest infrared image from the James Webb Space Telescope!"
They map the images into wavelengths you can see. There's nothing else the can do, other than not showing you the images at all.
IAmBroom 30 days ago [-]
Nonsense.
A screenshot of this page would capture a title bar in orange.
The REAL title bar is displayed as dots of green, blue, and red; no orange is present.
Simulacra 30 days ago [-]
I understand the necessity to approximate colors, but this article doesn't really explain the answer to the question. How much of the colors are simulated?
TheBigSalad 30 days ago [-]
Just assume everything in space is invisible to your eyes because they are tuned for Earth only.
IAmBroom 30 days ago [-]
97.3%.
AStonesThrow 30 days ago [-]
The article attempts to explain the difference between "colors" perceived by human eye, vs. wavelengths and signals received by artificial and scientific instruments.
"How much" isn't a question that makes sense, unless you are looking at a specific set of images. Astronomical images can be generated in many, many ways from all sorts of processes. Sometimes there is natural color included, but enhanced; sometimes a wider spectrum is mapped into visible colors so humans can appreciate it; sometimes, the colors are codes for different features, and there is a key provided, so that the colors can be interpreted to what they mean, rather than corresponding to visible light.
It's not just astronomical images, but all disciplines of science use color keys to depict things that are not colors. Look at a topographical map, and it may have green and brown areas that are simply abstracts. A political map uses 5-6 colors to highlight the shapes states or nations, but these are not "real" colors either. But usually, you're provided a color key, for interpretation.
> “False color” was popular for a while but has fallen out of favor because it implies fakery.
I think that's getting the priorities wrong. The people who think those images are "fake" and fraudulent don't think that because of that term, they just see the term as a reaffirmation of their preexisting conspiracy theories. Flat earthers will literally deny the evidence of their own experiments when they don't align with what they profess to believe.
Yet if some aliens insisted that our planet was a very boring featureless nitrogen-colored ball, we would probably object that their viewing strategy is naive and incorrect.
We are born seeing the universe based on pragmatic decisions about signal versus noise. Our evolved tuning utterly fails in new places, so we should pick new tunings.
And I'd argue that it's all signal. Noise is something very human -- maybe even for carbon-based lifeforms, but I'd be careful to make such broad assertion --, that which is unnecessary or harmful for the needs of the body.
Although space may appear subdued to our eyes, that doesn’t mean it isn’t beautiful—only that we need to borrow better eyes to truly see it
Color temperatures in the range of 5000 K to 7000 K, where the "yellow" stars belong, are all seen as pretty pure white, with the range of 5500 K to 6000 K, like the Sun, as the whitest. Even a colder star at 4000 K is only very slightly yellowish. Going to lower temperatures, e.g. 3000 K or less, the color becomes definitely yellow, then orange, then red.
You can verify this by looking at lamps with specified color temperatures, to see what color they seem to have for you.
The Sun seen from the Earth is seen as yellowish at noon and as reddish at sunset and at dawn because of the low-pass filter effect of the atmosphere, which removes the blue light from the direct light of the Sun and spreads it over the sky. When the blue sky light and the direct yellowish Sun light are mixed again, like in clouds, you see white light, thus the clouds are white, which is the real color of the Sun. On the Moon, without atmosphere, the Sun would be white.
Going towards higher temperatures, the white stars become blue-green, then blue. There are no green-emitting black bodies.
Though, you could say it's indirectly designed for beauty. When astronomers process an image, they are looking for interesting features to study. And once you've narrowed in on the most scientifically interesting way to process an image, the sorts of striking color contrasts that creates are inherently beautiful because they are unveiling the interesting parts & letting us see the unseen for the first time. And there is selection bias on what is interesting to look at. A violent explosion is both more aesthetically inspiring and teaches us more about how matter works than a picture of a random stairwell, and astronomers love their violent explosions.
That being said, the complaint that the images are "unrealistic" are off-base. The images accurately portray the information that was captured by the telescope. Your eyes often can't even see the wavelengths imaged by space telescopes (like the James Webb Space Telescope), so how you map those wavelengths to RGB is largely arbitrary. As long as you map them in the same order (shorter wavelengths appear bluer, longer wavelengths appear redder), I would consider the images accurate.
It is true that they also look at a lot of grayscale images, though. Differentiating chemicals in nebulas or on the surface of planets isn't always necessary, and you can always take the simpler (but sometimes less useful, since it doesn't make full use of the human visual system) route of looking at multiple grayscale images. A lot of the areas where false color is most useful are well-trodded ground, so we don't necessarily need more images of the same objects when the existing body of research is already rich. And sometimes, a researcher includes an image in their paper just because they thought it looked cool, not because it was useful for the methodology.
There are some rare cases in which an audible might look at a color image, but the overwhelming majority of images astronomers deal with daily are grayscale.
There are edge cases in which astronomers will load up images at multiple wavelengths and overlay them, but this is not the normal case. By and large, they're looking at a single channel at a time. Even more commonly than that, they're working with catalogs automatically generated from images.
Would you rather thaw NASA show you a blank image and say, "This is our newest infrared image from the James Webb Space Telescope!"
They map the images into wavelengths you can see. There's nothing else the can do, other than not showing you the images at all.
A screenshot of this page would capture a title bar in orange.
The REAL title bar is displayed as dots of green, blue, and red; no orange is present.
"How much" isn't a question that makes sense, unless you are looking at a specific set of images. Astronomical images can be generated in many, many ways from all sorts of processes. Sometimes there is natural color included, but enhanced; sometimes a wider spectrum is mapped into visible colors so humans can appreciate it; sometimes, the colors are codes for different features, and there is a key provided, so that the colors can be interpreted to what they mean, rather than corresponding to visible light.
It's not just astronomical images, but all disciplines of science use color keys to depict things that are not colors. Look at a topographical map, and it may have green and brown areas that are simply abstracts. A political map uses 5-6 colors to highlight the shapes states or nations, but these are not "real" colors either. But usually, you're provided a color key, for interpretation.
I think that's getting the priorities wrong. The people who think those images are "fake" and fraudulent don't think that because of that term, they just see the term as a reaffirmation of their preexisting conspiracy theories. Flat earthers will literally deny the evidence of their own experiments when they don't align with what they profess to believe.