What color is the universe?

[Admin]

Scientists have figured out the average color of the universe by recording visible light from more than 200,000 galaxies.

What color is the universe? : Read more

 

[Catastrophe]

I guessed white, but I was wrong. Well, a little off-right.

Cat

 

[Helio]

I guessed white, but I was wrong. Well, a little off-right.

Cat

Too funny!

 

[Helio]

Scientists have figured out the average color of the universe by recording visible light from more than 200,000 galaxies.

What color is the universe? : Read more

This 2002 project produced an initial conclusion of terqoise, tourqoise, turqosie... turquoise -- an absurd result given stars can't be green. But nobody could spell turquoise, , so they recalculated and discovered the actual color was closer to beige or "cosmic latte". [Here 'tis: Not Turquoise ]

Of course, another interesting answer, *cough*, would be to note that, with very long exposures, the result for space itself will be sky blue. Ask yourself why reflection nebulae are blue and note that all of space is comprised of the same stuff of reflection nebulae, just a lot less dense. It is the scattering of starlight (Rayleigh Scattering) that will bring to our eyes what space looks like, and the color scattered most, like our sky, is blue. [Fun in the Sun.]

 

[Pogo]

I think I’ll take it to the paint store and paint my living room that color.

 

[Catastrophe]

Just make sure it's not off-topic

Cat

 

[Catastrophe]

What color is the universe?
"figured out the average color of the universe by recording visible light from more than 200,000 galaxies."

Surely there can only be one answer. If you take the average it has got to be slightly off something?

Cat

 

[Helio]

What color is the universe?
"figured out the average color of the universe by recording visible light from more than 200,000 galaxies."

Surely there can only be one answer. If you take the average it has got to be slightly off something?

I can't tell how many times I've seen folks state that the Sun is white because it has all the colors. They fail to include that observed star color is the result of the intensity of each color, not just that all the colors are present. [Actually only three colors are necessary to produce white light, and I have heard only two may be necessary. The lighting industry takes advantage of this fact, as does your tv since there is no white pigment, only the RGB colors.]

Also, the latte color result is based on the average spectrum. But if you physically could group all the galaxies next to each other then stand back and look at it, the color would likely look a lot more white and a lot less latte. [an alliteration score would be welcome here. ]

The article actually addresses the issue (i.e. color constancy). Your eye/brain and cameras use the brightest and whitest source available in any scene as the reference white source, thus allowing better color rendering.

For instance, look at a car's old-style head lamp (not halogen or LED) during the daytime. It will have a strong tint of yellow. Look at that same headlamp at night and it will look primarily white; the nighttime yellow gets readjusted by the brain since the headlamp is the bright "white" source, whereas in the daytime, sunlight is the reference light.

 

[Helio]

I think I’ll take it to the paint store and paint my living room that color.

That would look good as the backdrop for the new Apollo command module control panel on your wall.

 

[Pogo]

RGB makes white because the rods in our retinas are designed for sensitivity centered around those three areas of the visible spectrum. White and the average color of the universe above is how the mix is perceived by our brains. The other thing is that most stars would appear pretty much white from orbit around each star because, although stars are described as blue, yellow, red, etc. each one emits all the spectrum, but, more so in those colors, a red star produces more red than the other wavelengths. But, because most of them have high luminosities compared to what our eyes are designed to perceive, most of them will saturate our eyes, thereby making them appear white. A lot of yellow, green, blue, etc. buy even more red. And so forth.

 

[Helio]

RGB makes white because the rods in our retinas are designed for sensitivity centered around those three areas of the visible spectrum.

I assume you mean our cones. The rods are very sensitive to any photon in the visible spectrum, though they have a peak in green, IIRC. [At low intensity, the rods contribute to the final color we see as light darkens. That color is something like lime green, which is why many emergency vehicles are now this color.]

The other thing is that most stars would appear pretty much white from orbit around each star because, although stars are described as blue, yellow, red, etc. each one emits all the spectrum, but, more so in those colors, a red star produces more red than the other wavelengths.

The extra white appearance when in orbit around a star is a good point. Astronauts don't say the Sun looks white to them from above, they say it looks "blindingly white". It is about 35% brighter seen from space than from down here. This intensity floods our color cones, located in the fovea. If all three of our color cones (RGB, if you like) are overloaded with photon flux then the color perceived would be white, painful white. This would be true of our Sun if it was, say, a yellow white, or any other color. The true color determination requires reducing the intensity to something tolerable (ie photopic vision). We see this in solar projections, but with some color distortion (extinctions) by our atmosphere.

But, because most of them have high luminosities compared to what our eyes are designed to perceive, most of them will saturate our eyes, thereby making them appear white. A lot of yellow, green, blue, etc. buy even more red. And so forth.

Exactly. Since they are so far away, they aren't bright enough to overload our eye/brain (retinex), thus we see their color a little better, though we can get more idea of their color when we take them out of focus.

One reason color might be better out of focus may be due to the fact that we only have 2% of our cones for the blue-seeing cones. Odd ain't it!?

 

[Pogo]

Yes, your are correct, it's the cones, not the rod, my bad.
The saturation thing was from an article many years ago in Sky and Telescope where most stars would appear as saturation white. It's mostly our atmosphere that makes the sun look yellow (or orange near the horizon).
Yes, most stars appear white, only a few have some color, especially those who don't look up very often. Many are surprised when they happen to spy Betelgeuse and Rigal not far apart, 'Hey, they are different colors!'
'2% of cones are for blue, Odd ain't it?' I agree.
I had also seen another article where before dinosaurs, protomammals and other phylums actually had four cones, red, green, blue and UV. When the dinos were king, mammals were small nocturnal critters and lost their UV and blue. When they disappeared and mammals evolved toward what we are today, we evolved blue cones from the green, and most mammals don't have color perception we do, the african monkeys evolved enhanced color perception as they were arboreal, we need to thank them. So, that's were the blue deficiency came from.
Our eyes just ain't the same as the rest of biology.

 

[Helio]

Yes, most stars appear white, only a few have some color, especially those who don't look up very often. Many are surprised when they happen to spy Betelgeuse and Rigal not far apart, 'Hey, they are different colors!'

Yes, only the brighter stars stand-out at night, but in number the red dwarfs are far more in number than the white stars.

Early stellar classification systems used color as one of the key indicators. One system was, apparently, based primarily off of a stars color. Fr. Angelo Secchi, father of the classification system, first classified stars by both their spectrums (absorption lines) and, secondarily, by their color. He used Capella as the comparative spectrum with the Sun. Since Capella does have yellow tint, he labeled these stars a yellow. White stars included Sirius, IIRC.

Since color correlates with temperature, and temperature is critical in classification and in the HR diagram, it is not surprising that the Sun just remained yellow since the late 1800s. But that's my opinion. [Sunsets and even Crayolas also have supported the allusion of yellow for a true Sun color.]

I had also seen another article where before dinosaurs, protomammals and other phylums actually had four cones, red, green, blue and UV. When the dinos were king, mammals were small nocturnal critters and lost their UV and blue. When they disappeared and mammals evolved toward what we are today, we evolved blue cones from the green, and most mammals don't have color perception we do, the african monkeys evolved enhanced color perception as they were arboreal, we need to thank them. So, that's were the blue deficiency came from.
Our eyes just ain't the same as the rest of biology.

Birds, being close to dinosaurs, still have four cones. I don't know if this is true of all birds, admittedly. White-tail deer are interesting because they can't see orange nor red hardly at all. Thus some hunters think their orange or red coat makes them invisible, but I think most hunters know that these coats are visible to deer because deer see these colors as black. However, these deer can see into the UV, so at sunrise, they see far better than we do, hence most deer probably see those deer hunters climbing into their blinds a little too late to not be seen by them.