Does white light exist as a physical phenomenon or only in perception?

[Tomtom]

Is it only in the eye that colors add up to be white?

I've been thinking a lot about how electromagnetic waves work.
The visible light is comprised of a electromagnetic radiation in the spectrum between 380 and 750 nm. Now, as far as I understand, if you "mix" all of these waves together, you get a color which the eye reads as white.

What I'm wondering about, is if this "appearing white" effect is something that only occurs in the eye, or if it is some physical quantity. (badly formulated).

Secondly, is white light actually all these different wavelengths "reacted" by constructively inteference?

Thirdly, if so, I'm wondering what it would look like if you were to draw a sinusoidal graph for "white light". Is this possible?

Thanks for any help!

 

[Nick89]

I am no expert on the matter, but as far as I know, white is only our eye's perception when all three different cones (in the eye) are stimulated in equal amounts. White is not present in the electromagnetic spectrum.

 

[Vanadium 50]

Color is a perception, not a physical phenomenon. Many different combinations of intensity and wavelength will be perceived as "white'.

 

[Tomtom]

Thanks! That was what I thought, but I was unsure. How about my second and third questions?

 

[Vanadium 50]

The answer to your first question tells you the answer to your second and third - they are based on a premise that is not how nature is.