Thread: Is the world gray?

I read in a articale once that the world is really gray or black and white that our brain makes us see colours so our performance is better if we can make a diffrence beetween object with colours so is it true that the whole universe is black and white or gray?

What the universe is, is full of electromagnetic radiation of varying frequencies. We have evolved to be able to both be able to observe the presence of light (black and white) and to distinguish between different frequencies of light within certain bounds (colour).

Originally Posted by Mateja78

I read in a articale once that the world is really gray or black and white that our brain makes us see colours so our performance is better if we can make a diffrence beetween object with colours so is it true that the whole universe is black and white or gray?

Colour is a purely subjective experience created by the visual system (eyes plus brain). This subjective nature of colour opens up the deep (1) philosophical question of "qualia"; i.e. is what you experience as seeing red the same as I experience.

However, the sensation of colour is generated by the objective reality of different frequencies of electromagnetic radiation and their reaction with objects in the real world. Human eyes have receptors turned to see a range of colours; different animals may have different receptors and hence see a different range of colours. For example, some birds can see into the ultra-violet. And, of course, some people may not see the same range of colours as others (e.g. colour blindness of various types).

(1) "Deep" in philosophy appears to mean "pointless".

Maybe the world is dark. You can only see light emmited from atom but you didn't see the atom, right? So the world is dark; what we see is just Electromagnetic Wave...

I'm interested. It is obviously presumed that car drivers see colour. Guide dogs? Not much use waving a white flag to a 400 LB. Grizzly bear? The fact that we ( humans see colour, nearly all of us ), means we have genetically developed this ability for specific reasons. Now, what would be the advantage of, ( for survival purposes ), seeing colours? westwind.

Finding ripe food

Knowing if you are covered in piss or raspberry marmalade.

And tasteing tomatoes MeteorWayne? westwind,

Can you have raspberry marmalade?? Surely not. Marmalade made from citrus, oranges etc. You are thinking of raspberry cordial KALSTER, or else you have lost your coloured marbles. westwind.

Originally Posted by Mateja78

I read in a articale once that the world is really gray or black and white that our brain makes us see colours so our performance is better if we can make a diffrence beetween object with colours so is it true that the whole universe is black and white or gray?

Hi Mateja Awesome question. I've always loved this topic. In short, there is no real acceptable answer so far besides stating there is no real acceptable answer. As far as we know, our human vision is wholly subjective. What we see and observe is not absolute reality, but a perception in the mind, dependent on our biological systems and the properties of electromagnetism. Like Einstein's relativity, there is no single absolute reference for which we can compare to. A long, possibly boring explanation filled with somewhat-related fun facts follows. Bear with me for a little...

Before a final answer, let's note some important concepts. The universe is full of electromagnetic radiation. You can visualize this radiation as a wave, kind of like a vibrating line traveling at a constant speed. The more the electromagnetic wave vibrates, the more energetic it is.

Radio waves are electromagnetic radiation, and have relatively little energy. X-rays are also electromagnetic radiation, but are much more energetic. The main idea is that radio waves, infrared, the light we see around us, UV rays, x-rays, gamma rays, etc. are all pretty much the same thing.

Not all of this electromagnetic energy is visible to us. Most of it, in fact, is there, but it's invisible to us. Our system only detects a certain range of electromagnetic energy that we call visible light, or simply, just light. This range is conventionally called the visible spectrum. We can't see any radiation that vibrates less or more than the visible spectrum. Within this spectrum, we perceive color.

We can't see infrared. It has no color, because, well, we can't see it in the first place. Infrared vibrates at too low a frequency for us to detect. The same goes for UV rays, except they are just a little too energetic for us to see. However, in between is our visible spectrum, where we perceive all the colors we ever see. We perceive the lowest visible radiation as red. And we perceive the highest visible radiation as violet. Between we have green, yellow, orange, blue, etc. When we combine all these visible frequencies, we get white light.

Here is the critical point concerning your question. What about blackness? Where does the color black come in? Well, if black is the opposite of white, what can we say about this? It turns out, that there is no black light at all. Why? Because blackness is the very absence of light. In absolute darkness, there is absolutely no radiation that is visible to us. Thus, in darkness, there is no color. We're used to the idea that black is some kind of color, one that is just as real or strong as "white", on the other side of the scale. Really, white light is like the full package; Black is just nothing. It is the absence of light, and consequentially, the absence of color, since you can't have color without light. Just wanted to point this out since it's a big misconception.

Now, about how we perceive color. Most of the objects you see around you do not produce light. An apple sitting near you is not emitting its own red light, unless you have some kind of alien radioactive apple. Neither does grass create green light. Or anything like that. The Sun, however, does produce light. A light bulb also produces light. A neon sign produces light. Almost all visible light is produced in energy-releasing chemical reactions, where electromagnetic energy is released, like the huge fiery ball we call the Sun.

Going back on wave vibration, or frequency. The color of the light we perceive depends on the wave's frequency. Again, red is the lowest frequency, and violet is the highest frequency. The in-between frequencies are all the other colors. The combination of these colors makes white light. You can think of three flashlights pointing at a certain point in the air. Take a red-tinted flashlight, a green-tinted flashlight, and a blue-tinted flashlight, and you shine all of them at a single point where the beams intersect. At this region, you have white light. The frequencies sort of overlapped each other, forming an overall perception.

When light is emitted, from say a light bulb, it travels in many directions within the room. The light travels extremely fast and bounces off objects. Sometimes, the light is even absorbed. Some things bend light or break it up into distinct colors, like a glass prism. Since we perceive color from light, we can only see colors from light that reaches our eyes. The light frequencies that are absorbed never reach our eye. The ones that bounce off, or get reflected, are able to be caught by our eyes. When white light hits grass in the yard, all the frequencies except those around the green ones are absorbed. The green frequencies, however, bounce off. Your eye "catches" this light, and you perceive the grass as green.

So, in conclusion: Without a light source, there is no light. Without light, there is no color, including any white. So we can say that without light, there is just nothingness, blackness. So it can't really be gray-scale since the scale is defined by varying potencies of white. Of course, it can't be any other color either, as already explained. Take into account that we only see a certain range of electromagnetic radiation. Visible light isn't the only radiation that exists in the world. It is also full of x-rays, gamma rays, radio waves, and the such. So what color would these things be? From here, it's best to just settle with indeterminate. Color is a matter of subjection.

EDIT: "Energy-producing chemical reactions" was a bad use of words. I am not against the law of matter/energy conservation. Edited and saved.

So what is it about and object that dictates a certain spectum of frequencies will not be absorbed but reflected away? Does it have something to do with the frequency of the matter?

Originally Posted by question for you

So what is it about and object that dictates a certain spectum of frequencies will not be absorbed but reflected away? Does it have something to do with the frequency of the matter?

It's complicated.

...

What's that? You want more? OK. It is related to the way the photons interact with the electrons in the material. Take a metal, for example, there is a "sea" of free electrons (which is why metals conduct electricity) this is why most metals are highly reflective.

But it is also to affected by things like crystal structure (a single crystal of salt is transparent, table salt is white), the surface texture, the available energy states of the electrons, and so on.

Take carbon, for example, this can be amorphous (no crystal structure) in which case it is black like charcoal. Or it can be in the form of graphite which has a regular structure and is shiny grey. Or it can be in a very regular crystal called diamond: this is transparent. Raw, uncut, diamnds are dull like bits of glass. Cut into facets and they sparkle like crazy.

Another example, butterfly wings can generate colours in two ways: pigments (see above) or optical effects such as interference.

In short, it is complicated.

Fun facts:
1) A glass is transparent, but a silicon crystal is black. Both is made from silicon!
2) An aluminum glass is transparent, but aluminium metal is white. Both is made from aluminium!
3) Silicon cystal is black, but aluminum metal is white. Both are crystal!
5) A glass are transparent, but a crystal is opaque (act as filter). Regardless of material!
6) Our cornea are transparent, but our retina is opaque. Both are organic material!
----

So its not just about 'what-atoms absorb what-light', its also about the crystal/atomic-arrangement/structure of the whole. It effect light!

Originally Posted by Strange

Originally Posted by question for you

So what is it about and object that dictates a certain spectum of frequencies will not be absorbed but reflected away? Does it have something to do with the frequency of the matter?

It's complicated.

...

What's that? You want more? OK. It is related to the way the photons interact with the electrons in the material. Take a metal, for example, there is a "sea" of free electrons (which is why metals conduct electricity) this is why most metals are highly reflective.

But it is also to affected by things like crystal structure (a single crystal of salt is transparent, table salt is white), the surface texture, the available energy states of the electrons, and so on.

Take carbon, for example, this can be amorphous (no crystal structure) in which case it is black like charcoal. Or it can be in the form of graphite which has a regular structure and is shiny grey. Or it can be in a very regular crystal called diamond: this is transparent. Raw, uncut, diamnds are dull like bits of glass. Cut into facets and they sparkle like crazy.

Another example, butterfly wings can generate colours in two ways: pigments (see above) or optical effects such as interference.

In short, it is complicated.

It sounds complicated! you given me more questions now!

Like how can a metal reflect it's metalic coulour... yet also act as a mirror and reflect the entire spectrum in the form of bright white? How can glass be see through and yet reflect the entire spectrum?

Rubber is non conductive so it must have very few electrons, which is why it's usually black?

This science muct be well explored in feilds of paint mixing? for art.

is there anything that has no electrons? if so would it be invisible?

To create an invisibility device... all you have to do, is make an electron feild were each individual electron is able to mimick the electrons directly behind the line of view. Easy peasy?

electrons are all the same?

So how do certain electrons or quantities of electron reject/accept different frequencies of light?

I need a nap.

Originally Posted by question for you

So how do certain electrons or quantities of electron reject/accept different frequencies of light?

In the atom, they can have different energy levels (you can think of this as distance from the nucleus, but that is only an approximation). When an electron absorbs a photon, it moves up an energy level. When it drops to another energy level it emits a photon. The frequency (colour) of the photon is related to the energy it has, which is the difference in the energy levels the electron moves between.

The available energy levels will determine which frequencies (energies) are absorbed, reflected etc. The available energy levels are determined in part by the structure of the atom, in part by the molecule the atom is in, partly by the crystal structure, etc.

In metals, there is a "sea" of electrons which can take a wide range of different energies and so metals tend to to reflect all frequencies equally.

But note that it is much more complicated than that ...