Why is it we have words for sounds and colors but not for smells?
I know what a banana smells like: it smells like the object it’s named for. It doesn’t smell yellow. And I can only further define the smell, based on the adjective of the name of the object, like unripe or ripe or overripe. Why isn’t there more of a science of smell?
On a piano, the key of A above middle C rings in at 440 Hertz and occupies a distinct notational space on the treble clef. The note “A” is often used as a tuning frequency. (Hear the violins in the orchestra warming up?) People with perfect pitch can hear someone singing or playing notes and name each one. For example, my piano teacher will tell me the last note she hears me play as she waits outside for me to let her in for my next hour of torture. She may say, “That was E-flat and your piano needs to be tuned.” Our Western music scale, all twelve notes zipping through an octave, say from C to C, stepping up and down from sharp to natural to flat, like a boot camp obstacle course, is called the chromatic scale.
Moving from ear sense to eye sense, there’s chromatics, the study of color. As with sounds, we have words for colors. Nothing beats opening a sixty-four box of crayons for the first time and experiencing the fabulous visual assault of cornflower blue duking it out with magenta, all those colors screaming Pick Me (and only one smell: crayon). We have names for particular bands of color, starting with Mr. Roy G. Biv (red orange yellow green blue indigo violet). We’ve studied the electromagnetic radiation of color such that we know wavelengths, frequencies, and energies all along the color spectrum. They have unique scientific notations (you can nail a particular shade of red down to its nanometer, Hertz, kiloJoule configuration) that make it easy for us to define, name, communicate a particular color. And I’m sure some interior designer has named that particular frequency Tuscan Red, or something. (Red, incidently, occupies a frequency interval of 430-480 teraHertz. So Nathaniel Hawthorne was prescient, coming up with that scarlet letter A for his adultering little number, the unfortunate Hester Prynne, and the creepy village that tuned her up.)
Onto the nose. Awkward organ. Smell scientist Noam Sobel of the Weizman Institute of Science in Israel has been trying to find the cogs and wheels of our olfactory mayhem (as are plenty of other scientists around the world, as a quick PubMed search shows). Sobel has snatched some of the olfactory molecules that latch onto olfactory receptors–we have a thousand of such smelly receptor types–attached to nerve endings in our nose, which, thus excited, ship electric signals to the brain which, in turn, produces a smell. Seems like it all happens in the nose, right? In any case, I believe the nostril’s the only place in our nervous system where nerves hit fresh air. Kind of like how our teeth are the only visible part of our skeletal system, hopefully.
Sobel is trying to sniff out a relationship between the structure of odor-producing molecules and their resulting smell. He has a database of 1,500 such molecules and a staggering catalog of 1,664 traits: their size, the strength of the chemical bonds between their atoms, and so on. (I thank Carl Zimmer, of Discover Magazine, May 2010, for this bit of nosiness.) So, for example, how tightly the atoms are packed determines the size of the molecule. These sizes are ranked on a continuum, and the farther apart molecules are from each other, the easier it is for folks to tell them apart by odor. Now I wish Carl articulated this concept better: Are the tiny, packed molecules the stinky ones? Odors grow more pleasant toward one end of the molecule-size continuum: Which end is it? How do I know which way to turn? I should probably read closer to the source but that would take me out of my current space-time continuum: http://www.jneurosci.org/content/27/37/10015.long .
Sobel’s whole endeavor shows us that we use another quality to define smell, besides the name and adjective of the overripe object, and that is whether it’s pleasant or unpleasant. We have the word (banana), the adjective (overripe), and the subjective emotion (yechh).
But still no word for the actual smell. Just circumstantial evidence.
Does anyone want to invent a lexicon for smell? Have we a sniffsmith equivalent of the umamis of tastebud lore? A nasal lexicon, anybody, beyond ‘it stinks’? First we have to isolate the odoriferous molecule that occurs in both sheet-seasoned male sweat and bleu cheese, well, and maybe stale peanuts, and give that particular molecule ONE name, like swepeanche, and go from there. It’s going to be a lot of work. Because, really, we should have a word for everything.
Sobel is working on a digital transmission of smell. With a digital grid of sorts, perhaps we will eventually say “that smell is like a good ‘locus P-440’!” and someone will punch that in and know what we mean. His e-nose stuff is at http://tinyurl.com/6qkbuc3.
I have a couple friends who have to smell EVERYTHING; they are supersmellers, not unlike the supertasters, and their brain-olfactory maps should be digitized and perhaps connected to this digital grid I’m imagining Sobel’s cooking up, for the preverbal, electronic definition we’re headed for, first, for smells. Then our supersmellers can tell us if swepeanche is accurately coded before we go bleach the sheets. And for the record, it’s not fair to blame males for that sweat smell (I had six brothers, sorry). It’s an odor-producing molecule belched from a harmless bacteria, not to be confused with a fun-guy.