I'm a grad student in cognitive psychology; my advisor works in the so-called "neo-Whorfian" literature.
What Sapir and Whorf were proposing is nowadays called "linguistic determinism" and is pretty much universally repudiated.
However, there is evidence for a less radical version called "linguistic relativity". For an example, see this paper: langcog.stanford.edu/papers/winawer2007.pdf
I haven't read the whole paper yet but I find it interesting that the Russian language prescribes a distinction between light blue and dark blue and that it just so happens that humans are more sensitive to blue than than red or green.
In fact, many expert Photoshop artists are aware of a trick whereby they can make small changes to the blue channel to get dramatic effects on the composite.
> humans are more sensitive to blue than than red or green
Without clarification, this is a nearly meaningless statement, but under the most plausible interpretations I can think of it is wrong [in particular, we have few "short wavelength" S cones in the fovea, the very central part of the retina, and it is the signal in these S cones which allow us to distinguish yellow from blue; the S cones contribute much less to lightness response than M or L cones].
What human vision is primarily sensitive to is differences between a color and its surroundings, and the relative sensitivity to differences along light/dark, red/green, blue/yellow dimensions depends enough on the size of the object, the prevalence of such differences in the rest of the scene, the state of adaptation of the eye, and so on. At small scale, we are most sensitive to lightness contrast, and two objects of similar lightness will tend to blend together at the edge even if they are of quite different hue.
"The sensitivity of the dark-adapted human eye is greatest at about 507 nm, a bluish-green color, while the light-adapted eye is most sensitive about 555 nm, a yellowish-green color"
It's why night-vision systems are geared to green, but displays that preserve dark-adapted vision are red.
> Ever been unable to think of a word for what you wanted to say?
Wouldn't that be an "unknown unknown"? My mother-tongue, Romanian, has a word called dor, whose exact meaning/translation I could never find in any English-written text. It doesn't describe unicorns in heavens or any such non-existent thing, in fact there is a similar term called saudade in Portuguese (http://en.wikipedia.org/wiki/Saudade), but the thing is that in order to get its full meaning you need to have it included in a larger text, because words by themselves don't mean anything.
Under conditions where you know there is a word for a thing but can't recall it or conditions where you don't know if there is a name for such a thing?
What Sapir and Whorf were proposing is nowadays called "linguistic determinism" and is pretty much universally repudiated.
However, there is evidence for a less radical version called "linguistic relativity". For an example, see this paper: langcog.stanford.edu/papers/winawer2007.pdf