Copying Smells, And Testing The Copies

In the visual and aural realms, we very often interact with reproduced versions of an original -- a photograph of a scene, a recording of a concert. And as long as you know what the original looked and/or sounded like, it's easy to tell whether it's an accurate reproduction. For smells, the same does not hold true. Unlike audio or visual reproductions, it's hard to transmit a reproduction of a smell to someone. There have been a few attempts, of course, but while something visual can be mimicked using wavelength and luminance and sound is a matter of copying the tone, odors depend on the brain's perception of molecules.