25 upvotes, 1 direct replies (showing 1)
View submission: How does the nose differentiate between thousands of different scents?
I just want to add that a full understanding of smell is something we don’t have yet. Just 25 years ago, we were theorizing that there were receptors for each smell. This would mean thousands of different receptors to smell the world around us.
Turns out most smell receptors have varying degrees of affinity for many different types of smells. The brain then processes the signals sent to it from multiple different receptors. A surprisingly large percentage of the human genome is dedicated to smell. It’s important.
One of the surprising features of human smell is our sensitivity to petrichor, or “rain/wet earth.” Humans use a lot of water and will need to find it when we travel long distances. Out sensitivity to this smell far surpasses the sensitivity sharks have for blood, so even though our noses are small, we have one of the most sensitive noses in the animal kingdom, but just for that one smell.
Comment by Sibula97 at 16/03/2025 at 09:44 UTC
2 upvotes, 1 direct replies
I remember reading an article about how our perception of the smell of chemicals matches quite well with their infrared absorption spectroscopy results, i.e. chemicals with similar absorption spectra smell alike. This could hint at our sense of smell being related to the vibration modes and energies of those chemicals.