optics geeks?

[danaeris]

So when a light ray passes into a different medium, the wavelength changes. Since wavelength and light color are directly related, does this mean that while the light is in that different medium, it will appear to be a different color?

Comments

Yep.

[the-ogre.livejournal.com]

The same thing happens with sound, too.

[random-vamp.livejournal.com]

As color is equivalent to wavelength, the answer would be yes. Thus the difference between viewing the world above a pool of water verses from beneath it.

[bk2w.livejournal.com]

Well, there's also the absorption of water that kills low frequency light pretty quickly.

[feylike.livejournal.com]

color is a perception of the human visual system. wavelength is related to color, but the human eye is not a spectroscope. for example, multiple combinations of wavelengths can result in the same perceived color -- these are called metamers. (incidentally, metameric pigments have interesting uses in anti-counterfeiting, as colors that appear identical under sunlight can appear different under other kinds of light.) look at poynton's color faq for some useful details about color.

anyway, while the wavelength of light does change when it passes from one medium to another of a different refractive index, that fact does not mean that the human eye will perceive it to be a different color. the wavelength as received by your retina remains the same. also, quantum interactions of light with matter (the photochemical processes in your retinal pigments are among these) depend on frequency, not wavelength. the frequency remains the same, regardless of what medium the light ray is passing through. (i presume that you're not going to worry about details like relativistic red-shift.)

[feylike.livejournal.com]

i had a long-ish reply to this which lj seems to have eaten. but the short answer is "no, and color vision is more complicated than that". i'll try to reconstruct the real answer later.

[epicureanangel.livejournal.com]

Wow.. those answers were interesting to read. :)

[feylike.livejournal.com]

that's weird. it reappeared without any obvious action on my part. perhaps there are some weird cache or database consistency issues with lj.

light in different mediums

[admiralthrawn.livejournal.com]

What do you mean "while the light is in a different medium"? When your retina is hit by a photon, it's inside your eye; whether it passed through air, water, glass, or whatever on the way is irrelevant -- the only medium that matters is the final one, which is constant (if the contents of your eyeballs are changing in a major way, you've got bigger issues than a change in the perception of colors...)