The answer, I dont know. Through my own findings, white light may be another color, and not a combination of colors as people may think. It all started one day, I was looking out at the picture window, and to my amazement, There was a rainbow. Not a big rainbow, but it was on the edge of the cloud. As time passed on, It started to change colors. First from all the colors in the rainbow, to slight blue, then to a very bright white.

I started to ponder a bit, and thought, how could I see white light when white light was all around us? Surely, it could have been a reflection off the cloud, but still, wouldnt the light blend in with the all the other light?

It struck me as odd since the Sun is Yellow, but yet, It provides White Light. Is is possible, that everything we see in the world, actually has an yellow tint, instead of the assumed white? So that means, everything we see, Has a yellowish Tint, and is actually a bit Dimmer than what it supposed to be.

So how is white just another color, and not a combination of all the colors on the spectrum? We all know we can get a prism, and all the colors will be there, but, whos to say that glass doesnt actually transform the light and not split it apart. How do we know, That the colors dont exsist, BUT only come in to exsistance when they are called apon (just like my theory on electricity and free electrons).

Picture a system with 2 prisims. White light enters one prisim, and the colors exit through the other to reform white light. In between the 2 prisims there is colored light. We all know we can see something colored because white light hits it and the color the object is colored in bounced back at our eyes, So how Can we see colored light even if There is No White light around? Well Something must be happening on a small level, aka Quantum Physics. Since there is no white light around, how can we see the colored Light?

Well the colored Light had to bounce off of something, Maybe, The protons in the colored light are bouncing off each other ( also effecting free electrons and protons) and thus we can see the colored light.

Ive drifted off point a bit too much from the orignal subject, So im going to end it here. I have a $25 gift card to B&N, Im still deciding if I should read Theory of Relativity, or that other book about the universe (or Hawkings Universe)

I learned in 7th grade that all light was a Spectrum of colors and frequencies.

It seems that you are more concerned about perception of colors than the true nature of white. I too have pondered this. As a person who "doesn't quite know the difference between red and orange" I have this often.

An interesting idea would be if you were taught as a child (as I sort of was) that the color brown is green. How dramatically would that impact your views on the world?

It would sure make dinner interesting when you were fed "Green" salad.

Quote: Originally Posted by BigAkita It would sure make dinner interesting when you were fed "Green" salad.

Getting your fiber a whole 'nother way...

I used to ponder stuff like that too...then I just said ehh...and drank some more beer.

God I hope I don't have to log in again and lose this.

Anyway, it took about three reads before I think I got what you were saying. I hope this gives you some food for thought.

a) You could see the white light, and the rainbow I guess, because of small particles of dust, smog, whatever in the air. Sunsets happen because more light is dispersed from the angle you see it at. I'd imagine you could see that one ray because the surrounding light WAS dimmer, or to be more accurate, there was less of it.

b) I wasn't sure whether you agreed that white is made up of all colors or not. As you said, the colors we percieve are from when light bounces off of an object. What also happens is with white light is that colors are absorbed. If you're wearing a blue shirt, green and red light will be absorbed as heat energy and blue light is reflected straight into your eyeball. If you're in a dark room with only a blue light, nothing is absorbed and the blue is reflected into your retina. Meanwhile, those wacky red pants of yours turn up black because blue is absorbed. If white light hits your black shirt, everything's absorbed, which is why black shirts are hotter than white ones.

Also, light does not contain protons, electrons or neutrons. It's massless (I think). I'm pretty sure there are still many things to learn about light (or optics) still though.

Light is a spectrum, dark is a conglomeration. Light is the splitting of color, dark is the coagulation of color. Ponder that.

Quote: Originally Posted by BigAkita Light is a spectrum, dark is a conglomeration. Light is the splitting of color, dark is the coagulation of color. Ponder that.

Hehe... that's my fave word.. coagulate.

More food for thought... Light is the conglomeration of coagulation...
My brain is addled, I just watched the Canadian Political debate on TV....

Quote: Originally Posted by _Sexy_Pants_ Also, light does not contain protons, electrons or neutrons. It's massless (I think). I'm pretty sure there are still many things to learn about light (or optics) still though.

While I agree that light doesn't contain protons, electrons or neutrons like all elements, Einstein postulated that it was made up of a particle called photons--its part of the whole "particle / wave duality" thing. While light does act as a wave, these photons can interact with electrons to produce electricity in the Photoelectric effect. So they have to have some mass. And then there's black holes...a source of gravity so immense that light can't travel fast enough to escape. It'd have to have mass for gravity to act upon it.

Either way, it still gives me a headache.

Yea thats what I meant, Photons..

Colors seen on objects is different than the colors of light emited from some source.

White light is indeed the combination of all visible light frequencies. What you saw out of your window were frequencies in a ray of white light being separated by some sort of prism, either water or glass.

Colors on objects are caused by pigments absorbing every frequency from a light source except for the frequency of light that matches the color you see, barring colorblindness. The color of light that the pigments do not absorb are reflected and your eyes catch the reflected color of light.

I'm recalling this off of the top of my head, if anybody can correct me through their textbook or reference material then by all means do so.

Edit:
The Sun produces white light as a byproduct of the fusion of hydrogen atoms into helium. If you were in space you would be seeing a white Sun, though you would also burn and die since the Sun produces every frequency of energy from radio waves, infared, visible light, ultraviolet, and higher radiation.

Think of this: at sunrise the Sun is one color, at noon the Sun is not the same color, and at sunset the sun is usually red. The color yellow is a result of light from the sun being refracted by our thick atmosphere and all the gas molecules in it. The color changes as the angle of the Sun in relation to us changes and as the light travels through the atmosphere at a different angle and thickness to reach us.

you can't see light waves except when it strikes an object. otherwise the dark void of space would be filled with light. rainbows are from the light hitting water particles in the air and defracting.

Quote: Originally Posted by DaSeph While I agree that light doesn't contain protons, electrons or neutrons like all elements, Einstein postulated that it was made up of a particle called photons--its part of the whole "particle / wave duality" thing. While light does act as a wave, these photons can interact with electrons to produce electricity in the Photoelectric effect. So they have to have some mass. And then there's black holes...a source of gravity so immense that light can't travel fast enough to escape. It'd have to have mass for gravity to act upon it. Either way, it still gives me a headache.

There we go! I was having some real reservations about saying that it was massless. Thanks for clearing that up

Quote: Originally Posted by Enko you can't see light waves except when it strikes an object. otherwise the dark void of space would be filled with light. rainbows are from the light hitting water particles in the air and defracting.

I'm pretty sure that the dark void of space is filled with photons, they either are too far apart to give any real intensity or are sucked into black holes. The stars you see at night are emitted light that has made its way into your retinas, they are not some bits of earth and sky emitting light because of some energy source.

To answer your original question, not all light is white. The only natural light produced is that produced by the sun, which is simply a huge hydrogen bomb. Like Hibiki said, the only reason light appears to have a "yellow" tinge to it here on earth's surface is due to atmospheric gases and reflection and refraction as the light changes medium (i.e. from gasless space to our gaseous atmosphere).

As far as a rainbow is concerned, when white light enters a prism, the light is split into seperate light rays and fundamental frequencies of the visible spectrum (i.e. red, orange, yellow, green, blue, violet). This happens because each color has a specific frequency in which deviates differently when refracting through the prism. Red is the lowest frequency of color in the visible spectrum while violet is the highest... the higher the frequency, the more the light ray will refract (or angle off if you will) when it is refracted.

Thus when you see a rainbow, light is hitting water droplets in the air and refracting within the droplet. The white light (or rather near white light due to the atmosphere) is refracted into the six fundamental colors. Since red is the lowest frequency of visible light, it is refracted the least while violet is the highest frequency and is refracted most. In relation to your body whilst you gaze at a rainbow, droplets higher in the air are refracting red light, while drops lower is the air are refracting violet and the other higher frequency colors. This is why red is always at the top of rainbows and violet is at the bottom. My craptastic picture illustrates this.

According to my ol' physics book, there is approximately 2 degrees difference in angle between red and violet rays when they leave a water droplet.

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Quote: Originally Posted by Jobistober To answer your original question, not all light is white. The only natural light produced is that produced by the sun, which is simply a huge hydrogen bomb. Like Hibiki said, the only reason light appears to have a "yellow" tinge to it here on earth's surface is due to atmospheric gases and reflection and refraction as the light changes medium (i.e. from gasless space to our gaseous atmosphere).

But that still doesnt explain why the sun is yellow when you also view it from space.

The best explanation I can give you is that the machines that take those pictures are configured differently to better analyze the Sun, with color fidelity being low priorty compared to energy studies. NASA has photos of a green Sun along with red, orange, and yellow ones.

Another posibility is that the hydrogen gas is burning on the surface and produces an ocean of fire, but that doesn't change the fact that the Sun produces all the frequencies of visible light that we group together and percieve as white light.

Edit:
The photos of the Sun are intentionally miscolored due to the emphasis on studying the properties of each layer of the Sun according to Encarta. The Sun is also made up of elements beside hydrogen and helium, for example calcium is there and produces a red color and invisible radiation. Each element does burn in the outer layers of the Sun and produce the frequencies of white light.

if the sun produced white light, it would be a white dwarf, which is where our sun would end up eventually. But according to a stars life, Our Sun is about 1/2 way through its life, by which is should glow a orangish yellow (or Yellowish orange).

The Sun is believed to have layers that produce the reds, oranges, and yellows according to spectography studies, but the light that leaves the sun and hits the planets orbiting it is white.

The other phases of the Sun's life will be determined by the availability of fuel, the adjustments to the properties of the Sun needed to perpetuate its existance, and eventually the slow cooling demise of the Sun. At those points the size, temperature, reactions, and energy emmisions of the Sun will change to something else or die out altogether.

Again, our knowledge of the Sun is limited by our observation tools, which have the habit of dying or getting disabled by something as powerful and violent as the Sun.

Edit:
Link from Stanford University: http://solar-center.stanford.edu/FAQ/Qsuncolor.html