Perhaps a little off topic of port, but isn't meaningless drivel, and smell is part of the enjoyment of wine, so I've posted this here.
For those that missed it. The second part of a recent BBC program on Quantum Mechanics showed how we smell is via at least two methods. The traditional lock and key approach using molecular shape and receptor sites is still valid, but doesn't explain how cyanide and almonds both smell the same but have completely different shapes. This is explained by the second method, where we listen to molecular bond vibrations (hence quantum mechanics). An apple smell molecule was modified switching a hydrogen for deuterium (hence the molecule was the same size but altered it's vibrations as deuterium as heavier) and trained fruit flies can tell them apart. (I don't know how you train fruit flies but guess it is via food. Training is always via threat/reward, and how else do you reward a fly?). The bonds on almonds and cyanide must vibrate in a sufficiently similar way that we can't tell them apart despite their different shapes. Fascinating.