Name: Why Do We Have Two Nostrils?
Uploaded: 2020-03-28T10:26:53.000Z
Duration: 9 min 23 s
Description: Thousands of YouTube videos with English-Chinese subtitles! Now you can learn to understand native speakers, expand your vocabulary, and improve your pronunciation...

have a lot of holes. We have two ears and two eyes.

It makes sense, because the difference in time it takes for a sound to reach one ear

allows us to localize where the sound is coming from.

And having two eyes gives us two slightly different perspectives that we

in order to perceive depth. But why do we have two

nostrils? I mean, our sense of smell isn't good enough to localize

one nostril over the other, why not just have a big hole in our nose,

like we have a mouth. Well, Stanford University's olfactory research

investigated this and they found that throughout the day

one nostril inhales air better and faster

than the other. Now, which one is dominant changes throughout the day, but having

a good air sucking nostril and a not so good

air sucking nostril is important. We need both,

because you see, odorants and molecules are absorbed by our skin and snot

at different rates. Some things are absorbed so quickly

they need to be rushed on the olfactory receptors before they're

molecules, other odorants, are slowly absorbed

and they need to be given time to get to the receptors and not just rushed right

And so having two nostrils allows us to smell

outer space. What would space smell like?

Okay, right, it's a tough question, it actually doesn't make much sense because

is a mere vacuum. If you went into space and took your helmet off to

smell it, well, all of the air in your lungs and throat, nose would be violently

sucked right out. In fact, even if you really tried to get some sort of

olfactory sensation, about all you would feel is the quick evaporation of

water coming out of your mucous membranes

and you might smell, for the few seconds that you were conscious,

nasal fluid and blood. That doesn't sound fun at all.

that have been taken out into space and then returned to a

habitable atmosphere, like inside a space station,

they went into space. Astronauts report that their suits,

after being in space, have a strange metallic

It's believed that the odor is caused by high energy particles

that cling to the suit and then, once brought inside,

smell. One particular type of high energy molecule found

all over interstellar space are polycyclic

aromatic hydrocarbons. These guys are the result

of combustion. And in 2004, the University of Toledo, Ohio found evidence

that those very molecules may exist in old

nebula. The result of convection currents  cooling carbon and hydrogen

Polycyclic aromatic hydrocarbons are also formed,

So, in order to train astronauts even more realistically here on earth,

NASA actually reached out to Steven Pearce of Omega Ingredients

to replicate the smell of things that have been to space

as a perfume. If we know the chemical makeup of something,

even something light years away from us, we can assemble those ingredients

here on earth and get an idea of what it would

smell like. Recently, researchers have discovered

Ethyl Formate in the dust cloud Sagittarius

and lift up your space suits visor and take a whiff,

you would die. You wouldn't be able to take a whiff, all of the air in your nose and

immediately expelled. But if you were able to take a

bucket of Sagittarius B2 home with you to earth

and then give it a smell, because of the ethyl formate

Pretty neat, right? But let's get closer to home.

Well, it's kind of hard to know because we are smelling it

all the time and our bodies become desensitized

to constant stimuli to keep us from being overloaded

and to keep us prepared to sense any out of the ordinary smells that

we might need to know about. This happens to us all the time.

When you first step into a restaurant, you can smell all the food,

but halfway through the meal you're no longer aware of the smell.

It's called neural adaptation. I guess the point I'm trying to make

is that in order to figure out what the inside of a nose smells like

like, for instance, smell the inside of your friend's nose.

It might seem weird at first, but it could be a great way to form

new memories. Our sense of smell may not be as acute as our other senses,

but it seems to be tied to memories very very closely.

A single whiff of an odor can instantly remind you of where you used to smell

and maybe even who you were with. This may be

because of the olfactories' connection to the limbic system

in the brain. Olfactory information is sent

through the limbic system, which is known to be involved with

emotions and memories. No other traditional sense is connected

to the limbic system in this way. We've also found

that patients who have memory loss caused by brain damage

Subtitles ListPlay Video

Why Do We Have Two Nostrils?

weird

perceive

process

gross