Does the term “monochromatic pink light” make sense? Could someone invent a “pink” laser?
My guess is, no. Pink doesn’t exist on the spectrum.
So, then, if you shine white light through a pink transparency, what’s coming through? A mixture of red and white? An ordinary white spectrum, but with an artificial bulge or spike in the red region?
Or is there no such thing at all as “pink” light, even as a blend of light spectrum curves? (Can you mix light spectrum curves?)
Not a homework question. (Ideas for a story I might write some day…)
Depends on what you’re using to make the light. Only very specialized devices can make a flat spectrum. Other times, you have to rely on a metamer that appears white. For example, many of the standard illuminants (see figures) might all appear white to us, but certainly aren’t spectrally.
ETA: But on rereading, a transparency does not create light, but filters out certain regions. If it is truly pink, then wavelengths (middle part?) will be attenuated.
Actually I am pretty sure it would not, at least, not if was the only source of light in a darkened room (and perhaps not under any circumstances). My “question” was not altogether serious. There is no such thing as brown light. Surfaces appear brown only by contrast with other surfaces in the field of view. If brown completely fills the field of view it will indeed appear as dim orange or yellow. The point to bear in mind is that not all experienced colors necessarily correspond to a wavelength of light, or even a mixture of wavelengths. The relation between color experience and the physics of light is far more complex than that.
Purple is a combination of blue and red. The question you probably meant to ask was why violet looks similar to purple.
To which the answer is mostly what you said, with a nuance: All light stimulates all of the receptors, but to various degrees. Differences in hue are due to the relative amounts that the different receptors are stimulated. It so happens that the red receptors have a fairly fat tail, but the green receptors don’t, so violet light stimulates both red and blue to some degree, but only very little green.
I am not sure if you are joking or not. If you are being serious, you are wrong (and did not very carefully read what I said).
No, there is no brown light and, as I said, the relationship between the colors we experience and the physics of light, and even the physiology of the retina, is not at all straightforward. As I also said, surfaces appear brown only when there are other contrasting colors in your field of view. This, of course, is the case, when there is brown on your computer monitor. Even if the brown entirely fills your screen, there is much in your field of view beyond the frame of the monitor. On the other hand, if you could arrange for light of the same mixture of wavelengths as are coming from the brown area on your screen to completely fill your field of view, it would appear orange or possibly some reddish or yellowish shade, not brown.
If anything, the right (long wavelength/redder) tail is fatter, not the left. Are you looking at the color matching functions or cone fundamentals? (check plot and click submit. the first section in each is sufficient for our purposes). The former is not quite the same thing; it means that if shown an e.g. 450nm light, you have to add lots of blue and less red/green to match it.
I’ve seen that demonstrated. They take an ordinary chocolate bar, and put it side by side with an orange color plate. They really are the same color. It kind of boggles the eye.
