For the foreseeable future, one of the tastiest tidbits of olfactory science will be this – the most accurate measurement of olfactory stimulus available to science uses light. That's right, the best way to know what a smell is, is to “see” it.
Smell comes from molecules, but not the kind you can see with the naked eye. Smelly molecules are vaporous, and vapors invisible. But on a molecular level, if you pulse a molecule with light, it emits light back. And if you measure the color of that light, you can identify the molecule. This is called spectroscopy, because instead of a yardstick, we use a spectrum of colors. And this is also called irony, because we use colors to smell. And this, is the nature of olfaction, because it is the most confusing, mysterious, and nonsensical of all our senses.
The same technological advances that are presaging quantum computation via optic modulators are refining molecular spectroscopy techniques: