Why do smells travel so far?
Smells travel through the air by a process called diffusion; air particles, and the odour particles within the air, move freely in all directions. They are constantly moving and eventually they spread out through the air around them.
It takes time for a scent to travel through the air - so yes, there is a speed of scent. The phenomena is part of how fluids mix so it does not get it's own name like sound and light does, and it's speed is much more variable.
The time it takes to smell a chemical in the air is the time the chemical takes to travel in air to our nose, and for the nerve impulse to travel to the brain (milliseconds), so smells are almost instantaneous.
Warm air is not as dense as cold air, so those molecules have more room to move around and they move faster, making them more available for us to smell. In the colder air, these odor molecules move slower and don't have as much room to move, making smells less available. Think about trash for a minute.
When you (and most other mammals) dive underwater, you can't smell anything because it is impossible to inhale without getting water in your lungs.
Whether odor smells will travel upward or downward then is not determined by the mass of their constituting particles (related to their vapor densities) but rather by their initial concentrations (or rather their gradients).
Wind and rain can affect how long scents linger. Scents can disappear quickly on hot, dry days because air currents carry scents away. On the other hand, scents linger longer on cool, wet days — especially on or near the ground. Heavy rains wash away odors and winds carry odors over a broader area.
Technically, yes, the molecules that diffuse through the air that we detect as smell are just as affected by gravity as everything else.
Sharks can smell blood from up to around a quarter of a mile away. When you smell something in the air, it's because scent molecules have dissolved into the wet lining of your nose.
In water, the concentration can be extremely low because many aroma molecules have only minimal solubility in water. The speed of diffusion of the aroma molecules is also much slower than in air because there are many more solvent or solid molecules in the way.
Can u smell in space?
A succession of astronauts have described the smell as '… a rather pleasant metallic sensation ... [like] ... sweet-smelling welding fumes', 'burning metal', 'a distinct odour of ozone, an acrid smell', 'walnuts and brake pads', 'gunpowder' and even 'burnt almond cookie'.
Jean Hunter, a food engineer at Cornell University, says that space travel can cause humans to lose their sense of smell. That loss, says Michele Perchonok, the head of NASA's food science program, may be due to the weightless environment.
An olfactory scientist weighs in.
No, it's not just your imagination; the air really does smell different right before it snows. According to olfactory scientist Pamela Dalton, that unmistakable snow “scent” can be boiled down to three things: cold weather, humidity, and a stimulated nerve in your brain.
There are many different factors that influence the variation between day and ninght. Temperature is one of them, perhaps the most important. Cooler temperatures reduce the concentration of volatile compounds, thus night air smells generally purer/cleaner.
The colder months hinder not just on the way scent travels through the air, but the way we perceive those smells, too. In the winter, the air is drier which inhibits the far travel of molecules to our noses. The colder it is, the fewer smells you can perceive.
Smells are carried in the water by the currents which disperse and carry molecules from things such as blood. Sharks nostrils are lined with sensory cells which are called “olfactory epithelium”. These cells can detect the tiny scent particles that are carried in the water.
Water passes over sensory cells within the skin folds. These cells pick up the scents in the water and then send signals to the shark's brain. In the shark's brain, the olfactory lobes kick in and analyse the scents, which can be those of a potential mate or prey.
Dogs noses are so finely-tuned they can even smell underwater thanks to the vomeronasal organ - commonly called the Jacobs organ. This organ runs along the bottom of their nose and connects directly to the olfactory lobe with about 600 nerve bundles.
If you smell an odour for long enough, you eventually stop noticing it. This is because prolonged exposure to a strong smell is believed to saturate the olfactory epithelium with odour molecules to the point where information is no longer delivered to the brain. This is called 'adaptation'.
From food to smoke to pet odors, Zillow explains that smells can move through central ventilation systems, pipe shafts or cracks in the walls. Some of these smells are more of an annoyance, while others may be more serious and might require attention.
Why do some smells stay in your nose?
You smell odors that aren't really there, but you think they're in your nose or somewhere around you. Phantosmia can develop after a respiratory infection or a head injury. Conditions such as Parkinson's disease, brain tumors, or inflamed sinuses may also trigger phantom smells in your nose.
An odor is a chemical molecule light enough to be swept around by the environment. Scents travel through air or underwater, before ultimately tripping sensors in our noses — known as olfactory neurons.
Your ability to smell comes from specialized sensory cells, called olfactory sensory neurons, which are found in a small patch of tissue high inside the nose. These cells connect directly to the brain.
Technically, yes, the molecules that diffuse through the air that we detect as smell are just as affected by gravity as everything else.
Wind obviously dictates the direction scent is carried, but wind speed can greatly impact the amount that scent disperses and how far from the source it carries. Many hunters will say they prefer calm and gentle wind conditions when hunting.
In water, the concentration can be extremely low because many aroma molecules have only minimal solubility in water. The speed of diffusion of the aroma molecules is also much slower than in air because there are many more solvent or solid molecules in the way.
The mean distance in the Olfaction condition was 289.0 cm (SD = 146.0; Fig 3). In the Control condition, it was 361.4 cm (SD = 153.2). In the visual Task Validation, as expected, performance was at ceiling (mean distance = 12.3 cm, SD = 33.5).
A succession of astronauts have described the smell as '… a rather pleasant metallic sensation ... [like] ... sweet-smelling welding fumes', 'burning metal', 'a distinct odour of ozone, an acrid smell', 'walnuts and brake pads', 'gunpowder' and even 'burnt almond cookie'.
When a guy smells your hair, it could mean that he's attracted to you and is trying to get a better sense of your scent. It could mean that your hair smells great and he's enjoying the smell.
Decades later, researchers hypothesized that the exceptional ability that smells have to trigger memories — known as “the Proust effect” — is due to how close the olfactory processing system is to the memory hub in the brain.
Which part of the brain is responsible for smell?
Smells are handled by the olfactory bulb, the structure in the front of the brain that sends information to the other areas of the body's central command for further processing. Odors take a direct route to the limbic system, including the amygdala and the hippocampus, the regions related to emotion and memory.
From the early 1960s, astronauts found that their taste buds did not seem to be as effective when they were in space. Why does this happen in space? This is because fluids in the body get affected by the reduced gravity conditions (also called fluid shift).
The odor clings to their suit, helmet, gloves and tools. Fugitives from the near-vacuum — probably atomic oxygen, among other things — the clinging particles have the acrid aroma of seared steak, hot metal and welding fumes.
After walking on the Moon astronauts hopped back into their lunar lander, bringing Moon dust with them. They were surprised, and perplexed, to find that it smelled like spent gunpowder.
Wind and rain can affect how long scents linger. Scents can disappear quickly on hot, dry days because air currents carry scents away. On the other hand, scents linger longer on cool, wet days — especially on or near the ground. Heavy rains wash away odors and winds carry odors over a broader area.
Jean Hunter, a food engineer at Cornell University, says that space travel can cause humans to lose their sense of smell. That loss, says Michele Perchonok, the head of NASA's food science program, may be due to the weightless environment.
No, it's not just your imagination; the air really does smell different right before it snows. According to olfactory scientist Pamela Dalton, that unmistakable snow “scent” can be boiled down to three things: cold weather, humidity, and a stimulated nerve in your brain. First things first: the weather.