Well?
The kryponite vapors inhibited his super smell???
Ahhh, but see: vapors are a chemical reaction. Kryptonite affects Superman because of its radioactivity. Not the same thing.
To smell it there would have to be kryptonite particles floating around. The particles would be radioactive. Not enough to cause damage, but probably enough to inhibit his ability to smell them.
AKA, I agree with watsonwil
Besides, any kryptonite particles would cause him to sneeze.
Maybe it smells just like chicken, so he never knows if it’s kryptonite or if Jimmy hit up the KFC again.
Can you smell plutonium?
[homer]Can’t you?[/homer]
See, if these kryptonite particles are radioactive enough to deaden his sense of smell, that’s just as good, if not better, than smelling them. ANY negative sensory organ reaction to a toxic substance should let you know there’s something wrong, especially if you’ve had that reaction before. It’s like… I dunno. Hay fever. You know there’s pollen in the air when your eyes get puffy, watery and irritated. That’s what we call a “symptom.”
I think I’ve exposed a big honking hole in the Superman mythos. I’m so giddy.
BrainGlutton. Point taken, but you and I are merely human. Neither of us possesses the olfactory sensitivity necessary to recognize and discriminate the odor of plutonium. But we’re talking Pre-Crisis Superman, here.
What makes you think pre-Crisis kryptonite gave off an odor?
Krytonite, being a rock, smells like well rocks.
Seeing as (or smelling as) Superman is smelling rocks pretty much 24/7, he kinds of tunes it out.
Kunilou: Because of the Second Law of Thermodynamics: everything material decays over time.
Odinoneeye: You tend to tune out the irrelevent and innocuous. You tend to notice things that hold special interest or signals danger of some kind (A baby’s whimper, the smell of smoke, slightly rancid meat.). Still, you’d think he’d pay attention to this particular set of scents (one, presumably, for each type of kryptonite) because of his vested interest in them means his continued survival.
Heck, I’ve oft-wondered why a man who could travel faster than the speed of light still got punched a lot. Learn to dodge, already!
Recent discoveries in the field of molecular biochemistry have shed light on this mystery. The sense of olfaction (the ability to detect and identify chemical substances) is common to all living organisms, and yet the mechanism by which this process occurs was poorly understood by scientists until modern molecular techniques could be brought to bear on the problem. In 1991, Richard Axel and Linda Buck revolutionized this area of study by describing a family of approximately one thousand genes that code for the odorant receptors of the olfactory epithelium [Axel and Buck, 1991 ]. This work won them the Nobel Prize in Physiology and Medicine for 2004.
We now know that the olfactory receptor cells are highly specialized, each posessing only a single type of receptor. These odorant receptors, which are classed as a variety of G-protein coupled receptor (GPCR), are embedded in the cell membrane and are triggered by a closely related variety of odorant molecules. Each type of receptor cell detects the presence of its target molecule, and all contribute to produce a unique mosaic “odorant pattern.” The olfactory system is thus capable of recognizing over 10,000 distinct odors.
In regard to Kryptonite, it must be emphasized that in order for the olfactory system to detect an odor, there must exist a corresponding odorant receptor to bond with the odorant molecule in question. Each receptor has a specific protien structure that can only accomodate a molecule of the necessary shape and size. Kryptonite is known to be chemically unreactive under most conditions: it will not oxidize under any circumstances, and no known chemical reaction can dissolve or otherwise destroy it. More significantly to the topic at hand, however, is the fact that Kryptonite was first generated via the chain reaction that destroyed the planet Krypton. Until this cataclysm occurred, Kryptonite did not exist in nature. Therefore, it is likely that the Kryptonian genome does not code for any odorant receptors that would enable Kryptonite to be detected by the olfactory system.
Terrifel. Oh, wow. This is the kind of speculation I was hoping for! Kudos for your response!
Until the turn of the twentieth century, synthetic plastic did not exist, right? Yet our evolved geonomes and receptor cells allow us to smell many varieties of polymeriized compounds easily. I think it’s likely that there are unique odors out there that our geonomes weren’t programmed for, but perhaps match receptor cells closely enough to fool them and for us to detect them anyway.
See, Pre-Crisis kryptonite is an heterogenous substance. It’s not wholly unique, nor is it a brand-new artificially made element. It’s just a chunk of native Kryptonian rock, ore, crystal, petrified organic substances, what have you, that was exposed to a space cloud and underwent SOME kind of chemical change that causes it to decay and emit radioactive wavelengths that, alternately, triggers bizarre biocellular xenomorphic reactions (y’know – lion heads or changing to an infant – or in the case of gold kryptonite supresses the bodies ability to process solar energy) or proves so toxic that prolonged exposure is absolutely lethal to Kryptonians.
Also, Pre-Crisis kryptonite isn’t nearly as chemically unreactive or indestructible as you think. It’s been cut into gem shapes and polished stone, dissolved by native acids, used as ingredient in chemical compounds — even used as a source of food. It may not give off any odors any human may ordinarily detect, (nor, perhaps a non-powered Kryptonian), but Pre-Crisis Superman under a yellow sun should be able to sniff out a nearby chunk like it was a soiled baby diaper. – or, alternately, react as if it were like cat hair.
Askia: Perhaps, although there seem to be any number of reasons why this would not be the case. For example, one could reasonably counter that, although Kryptonite was initially comprised of heterogeneous matter, it is clearly apparent that the chain reaction responsible for its creation rendered it homogenous in at least some, if not all, qualities: radioactivity, uniform color with corresponding somatic effects (generally restricted to Kryptonian life forms), and indestructibility come to mind. This last feature, in particular, seems to argue against a heterogeneous chemical composition for Kryptonite, since the material in question does not seem to exhibit any* relative degrees* of indestructibility. It is evidently not possible, for example, to damage a piece of Kryptonite-transmuted wood more easily than a similarly transmuted stone; at least, I am not aware of any such recorded comparison.
The above analysis refers specifically to green Kryptonite, as the properties of the other varieties have been less explored. However, it seems likely that they would also be uniform in their physical qualities, if not precisely identical to green Kryptonite. Red Kryptonite does not share green Kryptonite’s invulnerability and therefore can be burned and otherwise destroyed, which suggests that it is significantly more chemically reactive, and might therefore have a detectable odor.
Speaking of red Kryptonite, I am frankly puzzled by your assertion that all Kryptonite was originally heterogeneous matter exposed to a “space cloud.” All the information available to me suggests that the mass of the planet Krypton was converted into green Kryptonite by the chain reaction that destroyed the planet. A small fraction of this green Kryptonite rubble later passed through a mysterious “cosmic cloud” and was somehow converted into red Kryptonite, while other less common varieties of Kryptonite were created through distinct yet similar incidents.
I am uncertain that synthetic plastics provide a useful analogy for Kryptonite, since the distinct odor of some plastics is the result of outgassing volatile organic compounds, many analogs of which are found in nature. And, of course, many plastics have no discernible odor at all.
I confess ignorance of your cited examples regarding Kryptonite’s destructibility, and perhaps more specifics would cause me to reevaluate my position.
One last thought: regarding your suggestion that Kryptonian odorant receptors might be a close enough match to Kryptonite to trigger an olfactory response, it seems to me that this might in fact be the solution to the mystery. Each odorant receptor must accept a single molecule as a trigger; perhaps a single Kryptonite molecule, once in contact with the cell, is just enough to interfere with the enhanced olfactory capability of that particular receptor cell. However, bear in mind that the olfactory process makes use of many highly specific types of receptor cells, and any other odors will be percieved normally. Therefore a Kryptonian would retain their solar-enhanced olfaction, *with the specific exclusion of the ability to detect Kryptonite molecules in this manner. *
The fact remains that, according to canon, kryptonite dust makes Superman sneeze. He could be alerted to its presence by the fact that he is sneezing, but the allergy would probably affect his sense of smell so that he couldn’t notice any particular smell, just as you wouldn’t notice the smell of a particle of dust that makes you sneeze.
He’d need some absurd made-up “Super Smelling” power to pick up the scent; that would be just plain silly next to his other more sensible powers (such as super-ventriloquism, or super-breath).
Super-ventriloquism? Huh? 
You’ve never heard of “super-ventriloquism”? Unlike stage performers who only pretend to throw their voices, Superman could actually make his voice sound exactly like it was coming from another room – or even miles away.
Vocal and Ventriloquistic PowersIn January 1950, Superman ventriloquizes over a considerable distance in order to make a painted image of himself appear to talk and in order to make his voice materialize from a police-car radio. This technique, which later becomes known as “super-ventriloquism,” enables Superman to project his voice over immense distances and yet have his voice heard only by those whom he is directly addressing.