It appears that a discovery has been made, all over the place and all at once, about how the mixture of air changes the way smells are perceived.
It's not at all unusual that multiple simultaneous discoveries have appeared, in fact it's the rule not the exception in science. The articles below all seem to have discovered that a turbulent cloud of odor molecules smells different than what I'll call a more homogenous, slow-moving cloud.
Based on the above image, see the great CFD video illustration of air movement here.
It's like you're getting a more representative sample. When smells occur in your environment, they move as streams and plumes, picture wisps of smoke. If you're about to "sample" a piece of data, it means you're about inhale a cubic foot of air. What are the chances the amount of molecules you need to register an odor will be in that cubic foot? If you were to snapshot the cube before you inhale, you could imagine the airsteams of the odor you're looking for, let's say the scent of a female moth pheromone, twirling through the cube. But if you shook up all the air around you, to get into your breathing space some of the airstreams from outside the space, then you get more chance that the target molecule will make it into your "sample" sniff. From a statistical point of view it does make sense - you're squeezing more airstreams into a smaller space and time.
Study suggests that 'Jedi' rodents remotely move matter using sound to enhance their sense of smell
Oct 2024, phys.org
Surprise! "This phenomenon has never been observed before, or I believe even suspected, in any animal"
(This is from a bioacoustics researcher btw.)
Scientists have debated the purpose of the ultrasonic vocalizations (USVs) produced by rodents since the discovery of these sounds in the 1950s. This new paper suggests they do it to shake up their surroundings in ways that influence how inhaled particles enter their noses, suggesting that rodents use sound to enhance their sense of smell."They're creating new pathways of information by manipulating their environment and controlling the molecular interactions of particles around them."Rodents explore their environment by stroking surfaces with their whiskers, visually scanning, and incessantly sniffing. Mercado discovered that studies on vocalizations that also monitored sniffing showed that rodents immediately sniffed after producing each USV."That could be a coincidence, or it might suggest the two are functionally related," he says. "I knew that techniques for using ultrasound to manipulate particles are used in the field of vibroacoustics and thought immediately that might also work for animals."Vibroacoustics, or artificially produced ultrasonic vibrations, cause airborne particles to cluster, leading Mercado to suggest that rodents are using USVs to create odor clusters enhancing the reception of pheromones (chemical signals), thus making it easier for the vocalizer to detect and identify friends, strangers, and competitors.
via University at Buffalo: Eduardo Mercado et al, Do rodents smell with sound?, Neuroscience & Biobehavioral Reviews (2024). DOI: 10.1016/j.neubiorev.2024.105908.
Study uncovers how silkworm moth's odor detection may improve robotics
Oct 2024, phys.org
They employed high-speed photogrammetry to computationally analyze the aerodynamic consequences of wing motions of the silkworm moth (Bombyx mori).This insect that no longer flies due to domestication, but does flap its wings when they detect pheromones.One of the key findings of the study was that B. mori samples the pheromone selectively from the front. The moth scans the space by rotating its body while fanning to locate the pheromone sources. The directional sampling of the pheromone molecules is particularly helpful when searching for an odor source since the moth can determine the direction of the odor plume upon the detection of the pheromone.This could lead to advancements in robotic odor source localization technologies, where drones equipped with insect antennae for odor detection carefully adjust their orientation and the configuration of their propellers and odor sensors to optimize detection capabilities.
via Chiba University Graduate School of Engineering: Olfactory sampling volume for pheromone capture by wing fanning of silkworm moth: a simulation-based study, Scientific Reports (2024). DOI: 10.1038/s41598-024-67966-y
People with no sense of smell found to have abnormal breathing patterns
Oct 2024, phys.org
The researchers sought to address anecdotal accounts of people who could not smell and began "breathing funny" after contracting COVID-19.The research team recruited 52 volunteers, 21 of whom were suffering from anosmia, and fitted them with a breathing monitor for 24 hours.The research team found that those volunteers with anosmia did have slightly different than normal breathing patterns. People without the condition, they note, have small inhalation peaks, which prior research suggests coincides with a suspected change in smell. People without the ability to smell had no such peaks.
via The Azrieli National Institute for Human Brain Imaging and Research: Lior Gorodisky et al, Humans without a sense of smell breathe differently, Nature Communications (2024). DOI: 10.1038/s41467-024-52650-6
