What’s Really Happening When You "Smell" Snow

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iStock

Does snow have a scent? The logical side of your brain may say no: Snow is just frozen water, and therefore odorless. But if you’ve ever predicted a big snowstorm based on a familiar tickle in your nose, you know the answer isn’t so straightforward. So what exactly is happening when you “smell” a meteorological event? The answer has less to do with specific odor molecules as it does with the climate in which you smell them.

For an episode of the podcast Physics Central, olfactory scientist Pamela Dalton laid out the perfect storm of physical conditions you interpret as the smell of snow. When temperatures approach freezing right before it snows, it’s actually harder to detect scents in the air than it is during milder weather. Cold weather slows down molecules in the air, and with less molecular activity, certain smells become less pungent. That means “smelling snow” is, in part, just smelling fewer odors outdoors than what you’re used to.

But if there was nothing else to it, a snowstorm would smell no different than a cold, dry day. The factor that determines the difference is humidity. Right before a snowstorm, the air is more humid than usual. This is what causes the flakes to fall: When the atmosphere hits the maximum amount of moisture it can hold, it reacts by dumping some of the moisture—whether in the form of rain, sleet, or in this case, snow—back onto the ground. That humidity has the added effect of giving your olfactory system a quick boost. To many people, the sensation of being able to smell with a warm, moist nose in freezing weather is linked with the promise of snow.

As all of that’s happening to the world around you, there are mechanisms at work inside your body that also help to explain the unmistakable scent of snow. You sense the cold air you breath with your trigeminal nerve, the same nerve that interprets sensations caused by tingly hot peppers or cool mint toothpaste (it also interprets other facial sensations and is why you might sneeze in sunlight). This is separate from your olfactory system, but you still lump the information it gives you with conventional scents like coffee or pine.

These elements—cold weather, humidity, and a stimulated trigeminal nerve—combine to create something that isn’t an odor, but a sensory experience you’ve come to associate with snow. That’s why when asked to describe the scent, people often use words like “clean,” “fresh,” and “cold"— a.k.a. things that don’t have much of a scent at all.

[h/t Physics Central]

Shocker: This Electric Eel Delivers More Voltage Than Any Creature on Earth

stacey_newman/iStock via Getty Images
stacey_newman/iStock via Getty Images

Eels are proving to be more slippery than previously believed. A newly identified species of these skinny fish (yes, eels are really fish) delivers more electric voltage than any other creature on the planet.

All species in their taxonomic order (Gymnotiformes) are capable of producing a modest electrical field to help them navigate, a perk that compensates for their poor vision. But electric eels (in the genus Electrophorus) pack a far more potent punch. They bear three organs full of cells that can produce electricity on demand. The cells act as a defense mechanism and can effectively taser prey into submission.

In a study published in Nature Communications, researchers collected more than 100 electric eels in the Amazon region and analyzed their DNA, voltage, and habitat. To their surprise, they found that the single known species of electric eel, Electrophorus electricus, was actually three distinct species. They gave the two new ones the very heavy metal names of E. varii and E. voltai. The latter (named for Alessandro Volta, who invented the electric battery) produced the strongest shock: 860 volts, topping the previous record of 650 volts.

Why the varying strength? The researchers suggested that some eels occupy water with low salt content, and therefore reduced conductivity. A stronger charge may be needed to deliver an effective jolt.

While those numbers sound formidable, their low current means a shock wouldn’t necessarily be harmful to a human. Voltage is the measure of pressure of the flow of electrons; current, or amperage, is the volume of electrons. Eels have high voltage but low current; household power outlets have lower voltage but more current and can be deadly. Eels might startle you with a shock, but it won't be fatal.

If you should find yourself in a school of electric eels bent on subduing you, however, the shocks could result in brief incapacitation that could lead to drowning or an aggravation of an existing heart condition. The study authors hope to eventually film a coordinated eel attack on (non-human) prey.

The discovery of two new species was “quite literally shocking,” lead author Carlos David de Santana told The New York Times.

[h/t Phys.org]

Does the Full Moon Really Make People Act Crazy?

iStock.com/voraorn
iStock.com/voraorn

Along with Mercury in retrograde, the full moon is a pretty popular scapegoat for bad luck and bizarre behavior. Encounter someone acting strangely? Blame it on the lunar phases! It's said that crime rates increase and emergency rooms are much busier during the full moon (though a 2004 study debunked this claim). Plus, there's that whole werewolf thing. Why would this be? The reasoning is that the moon, which affects the ocean's tides, probably exerts a similar effect on us, because the human body is made mostly of water.

This belief that the moon influences behavior is so widely held—reportedly, even 80 percent of nurses and 64 percent of doctors think it's true, according to a 1987 paper published in the Journal of Emergency Medicine [PDF]—that in 2012 a team of researchers at Université Laval's School of Psychology in Canada decided to find out if mental illness and the phases of the moon are linked [PDF].

To test the theory, the researchers evaluated 771 patients who visited emergency rooms at two hospitals in Montreal between March 2005 and April 2008. The patients chosen complained of chest pains, which doctors could not determine a medical cause for the pains. Many of the patients suffered from panic attacks, anxiety and mood disorders, or suicidal thoughts.

When the researchers compared the time of the visits to the phases of the moon, they found that there was no link between the incidence of psychological problems and the four lunar phases, with one exception: in the last lunar quarter, anxiety disorders were 32 percent less frequent. "This may be coincidental or due to factors we did not take into account," Dr. Geneviève Belleville, who directed the team of researchers, said. "But one thing is certain: we observed no full-moon or new-moon effect on psychological problems."

So rest easy (or maybe not): If people seem to act crazy during the full moon, their behavior is likely pretty similar during the rest of the lunar cycle as well.

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