What is light?

[Shadow1]

What is light exactly, i mean, it's not something you can see while it's in air, and does light is what interact with some chimicals that are in everything, to generate colours? also, what are colours? are they chimical interact with light or what? for example if you was in a dark room, no light in it, and all closed, you'll see everything in black, no colours, all in black.
does colours exist? or it's just our eyes, that gives us the ability to see some interacts wich are colours, for example, some animas only see in black and white, i think it's the dog, or the cat, some others, see in red, i mean, see everything "redish", like some snakes, or all snakes, anyway...
so what is light exactly, and what are colours?

 

[Blindman]

Light is a particle/wave traveling through space. It has a frequency/energy. We humans interpret it as colour and brightness. It is just electromagnetic energy. Psychology makes it complex.

 

[cosmictraveler]

What is light?

The opposite of dark.

 

[Kernl Sandrs]

What is light exactly, i mean, it's not something you can see while it's in air,

Rainbow? Colored light, but light nonetheless.

and does light is what interact with some chimicals that are in everything, to generate colours?

Sentence structure. Articulation. Grammar. You lack these things.

also, what are colours?

http://www.merriam-webster.com/dictionary/color


Open Browser>go to Google.com>Enter keyword "Color">Click links>smash face against monitor;

are they chimical interact with light or what? for example if you was in a dark room, no light in it, and all closed, you'll see everything in black, no colours, all in black.

Actually you wouldn't see anything. Because of the lack of light hitting your eyes, you don't see what's in front of you, but the blackness that you're describing is not a color phenomenon, it's just an absence of light.

does colours exist?

or it's just our eyes, that gives us the ability to see some interacts wich are colours, for example, some animas only see in black and white, i think it's the dog, or the cat, some others, see in red, i mean, see everything "redish", like some snakes, or all snakes, anyway...
so what is light exactly, and what are colours?

I don't know where you heard that, but whoever told you is very misinformed.

What a human sees:

What a dog sees:

Many animals have the ability to see colors. This ability is based on the types of visual pigments in a cell.

There are animals known with 2, 3, or 4 different pigments or visual cell types. Humans have 3 different pigments and can differentiate about 200 colors. Most of this analysis is done by the brain, not the eye. Therefore, it is difficult to tell how many colors an animal can differentiate based on the number of their eye pigments alone.

Many fish can see colors (e.g. Phoxinus, Crenilabrus). Some amphibians can see colors (frog: Rana temporaria, toads: Bufo bufo, some salamanders) and they usually have two pigments. Most reptiles can see colors (snakes, turtles). Birds: general rule: birds that are active during the day can see colors, but birds that are acitve during the night cannot. Mammals are generally bad in color vision. Examples of color-blind mammals are rats, hamsters, rabbits, and dogs. Cats are weak, but can see some colors. Mammals that are quite good are guinea pigs, sheep, zebra, horses.

Also some invertebrates are able to see colors. Some Cephalopods (e.g. sepia, but not octopus). Crabs are generally good in color vision. Many insects (all beetles, hymenopterans (bees, wasps, ants), homopterans (ture bugs), and all flies. All insects are unable to see red light (only known exception are ants), but some are able to see UV (ultraviolet) instead.

The color vision was determined by training an animal to respond to a color or by measuring the electrical response of single visual cells or the whole eye.

See also:
http://www.madsci.org/posts/archives/oct98/905228364.Zo.r.html

http://www.colormatters.com/kids/animals.html

http://www.wisegeek.com/do-animals-see-in-color.htm

 

[Shadow1]

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The opposite of dark.

no, their's nothing called "darkness", because darkness is the absense of light, also cold don't actually exist as you can call it cold, cold is the absense of fire, or light, or heat or whatever you want to call it.

 

[Shadow1]

.

Light is a particle/wave traveling through space. It has a frequency/energy. We humans interpret it as colour and brightness. It is just electromagnetic energy. Psychology makes it complex.

ah,i see, but apparently your avatar don't. hehehehe

 

[Shadow1]

Rainbow? Colored light, but light nonetheless.

no i didnt mean rainbow, or colored light, but, what did you mean with "nonethless"

Sentence structure. Articulation. Grammar. You lack these things.



http://www.merriam-webster.com/dictionary/color


Open Browser>go to Google.com>Enter keyword "Color">Click links>smash face against monitor;

ah, ok thanks, i think i made the mistacke cause i stranslated the word from arabic in the google translator.

describing is not a color phenomenon, it's just an absence of light.

yeah i know about it, i just told that to cosmictraveller, before replying on this one

I don't know where you heard that, but whoever told you is very misinformed.


What a human ...

ah thanks, i'll check them out

i readed once about top 10 weird diseases or special cases in humans, one of those was, the ability to see around 2500colours(i can't remember well, but it's at that number zone) instead of 200/i'll try to find the link and post it later.

 

[Kernl Sandrs]

no i didnt mean rainbow, or colored light, but, what did you mean with "nonethless"

A rainbow is light. Well, light and water, but when you look at a rainbow what you're seeing is light and water particles.

"nonetheless" is a conjunctive adverb. A conjunctive adverb is an adverb that connects two clauses. Conjunctive adverbs show cause and effect, sequence, contrast, comparison, or other relationships. It's really one of those things you could go your whole life without knowing. When I said that, I meant that despite being colored it is still light, which is what you were talking about. Even though you weren't talking specifically about colored light, it still applies.

ah, ok thanks, i think i made the mistacke cause i stranslated the word from arabic in the google translator.

Yes, it is not very reliable.

 

[Votorx]

What is light exactly

At this moment, light is commonly thought of as an electromagnetic wave. Very interesting stuff I'd recommend doing some research about it.

does light is what interact with some chimicals that are in everything, to generate colours?

Kind of. When light is absorbed by our eyes the "color" we see is actually the wavelength of the light. Different wavelengths of light makes our brain perceive different colors. Its important to understand that the color we see is the wavelength of light being reflected off the surface of the object we're viewing. Taking plants as an example, most plants are green because plants are unable to absorb green light, therefore it reflects those wavelengths and that is why plants appear green to us.

http://eosweb.larc.nasa.gov/EDDOCS/Wavelengths_for_Colors.html

for example if you was in a dark room, no light in it, and all closed, you'll see everything in black, no colours, all in black.

Correction, if there was no light you wouldn't see anything at all. If you can see anything, then light is present, even if you can't distinguish it's source.

does colours exist? or it's just our eyes, that gives us the ability to see some interacts wich are colours, for example, some animas only see in black and white, i think it's the dog, or the cat, some others, see in red, i mean, see everything "redish", like some snakes, or all snakes, anyway...
so what is light exactly, and what are colours?

Colors "exist" as constructs of the mind. Color doesn't "exist" outside the mind. Its kind of like asking...."If a tree falls in the woods and no one is around to hear it, does it make a sound?". No it doesn't. Sound is also a construct of the bind. Instead, the tree would produce waves in the air that would be perceived as sound if anything was nearby when it fell.

 

[Votorx]

for example if you was in a dark room, no light in it, and all closed, you'll see everything in black, no colours, all in black.

I think I understand your question a little better the second time around. If you're in a room with very little light then you will only see in black and white. That is because there are two type of specialized cells in the eyes. For simplicity we'll call them cones and rods.

The cone cells are used to produce sight when dealing with bright light and account for all the different colors we see.

The rod cells are used when dealing with low intensity light and are only able to see in black and weight, but deal with the light our "cone cells" aren't equipped to handle.

 

[Acitnoids]

Originally Posted by Shadow1
What is light exactly, i mean, it's not something you can see while it's in air, and does light is what interacts with some chimicals that are in everything, to generate colour? also, what are colours?

Light is also known as electromagnetic radiation and it is broken down into seven different varieties depending on the wavelength. This is called the electromagnetic spectrum. Radiowaves have a wavelength longer than 30cm. Microwaves have a wavelength between 30 - .3cm. Infrared runs between .3cm - .7 microns (um). The Visible Sectrum has a wavelength between .7 - .4um and this is the portion of the EM spectrum that we humans see with our eyes. A visible wave of .7um appears as the color red, .55um appears greenish, .45um appears bluish and .4um appears as the color violet. When all of these wavelengths are viewed together we call it 'white light' and the color of any object depends on which of these wavelengths are absorbed or reflected. Black objects absorb all the white light while white objects reflect all of it back into space. Next comes Ultra Violet radiation which has a wavelength between .4um - 3 nanometers (nm). X-Rays run between 3nm - .03nm and finally Gamma Radiation is any electromagnetic wave smaller than .03nm. This shows that the shorter the wavelength gets, the higher the energy level of those photons.

... if you was in a dark room, no light in it, and all closed, you'll see everthing in black, no colours, all in black.

Well, the absence of visible light does not mean there is a total absence of radiation. Some night vision devices work by turning IR light into visible light. Anything that gives off heat does so in the UV spectrum. Our eyes may not be able to these forms of light (hence the darkness) but I assure you that there is always some form of electromagnetic radiation present.

 

[Shadow1]

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ah, thank's guys, now i get it clearly!

 

[Shadow1]

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I think I understand your question a little better the second time around. If you're in a room with very little light then you will only see in black and white. That is because there are two type of specialized cells in the eyes. For simplicity we'll call them cones and rods.

The cone cells are used to produce sight when dealing with bright light and account for all the different colors we see.

The rod cells are used when dealing with low intensity light and are only able to see in black and weight, but deal with the light our "cone cells" aren't equipped to handle.

yeah, i meant if their's no light, there's no colour, anyway,
thnks for clearing things up,