- [Narrator] Here at Be Amazed, we like to ask some of
life's biggest questions. Like, will I die if I consume Coke and Mentos at the same time? Why do humans have chins? And how long can I hold in
a fart before I explode? If these sound like the kinds
of things you need answering, then stick around to find out a whole host of quirky things you
never knew about your body in this edition of the
Ultimate Facts Show. (upbeat music) Why do we cringe at the sound
of nails on a chalkboard? There are very few sounds
that are as universally hated as the cringe-inducing screeching of nails being dragged down a chalkboard. The only sounds that
arguably have similar effects are a fork scraping on a plate, (fork scraping) a piece of chalk on slate, (chalk scraping) or a heavy metal chair being
dragged across a tile floor. (chair screeching) But what is it about these scraping sounds that make them so unbearable
to our oh-so-sensitive ears? Thankfully, researchers
embarked on a project to get to the bottom of this
burning query back in 1986. In their study, the trio hypothesized that it was the high pitched sounds that caused us to recoil in horror, so they isolated the
sounds between low, middle, and high frequencies. After playing these
recordings to test subjects, they found that they were
actually completely wrong. Removing the high frequencies didn't make the sounds any more bearable, but remarkably, removing
the middle frequencies did. Then they made an even
more surprising discovery, it turns out the sound waves associated with primate warning cries, particularly chimpanzees,
are spookily similar to the aversive middle
frequency sound waves produced by fingernails on a chalkboard. So the reason why we can't
stand the sound so much could well be because it
triggers us in an unconscious, automatic primal response that we're hearing a shrill warning cry. Who'd have thought? Even the thought of hearing
nails down a chalkboard is making me cringe right now. At least now I know why. When I balance the cringe
out with another sound, like the super satisfying click you hear when you smash those Like
and Subscribe buttons. Oh, and don't forget to play around with that little bell icon too, so you never miss out on
any more amazing content. Now, let's get back to it. (soft music) Can drinking Coke after
eating Mentos kill you? Ah, the old Diet Coke
and Mentos experiment. Unscrew the cap, drop
in a row of minty candy, and watch as an impressive
geyser of soda erupts into the air like a volcano that has been dormant for many years. The science behind it is pretty simple. Although the Mentos looks smooth, they actually have a rough outer coating, which breaks the bonds
between the carbon dioxide gas and water in the diet Coke, creating carbon dioxide bubbles,
which cause the eruption. Thankfully it's just an urban myth that the same reaction can
happen inside your body. That's because the rough
coating on the candy starts to dissolve pretty much as soon as you put it onto your tongue. Putting Mentos into your stomach and then chugging a glass of Coke would most likely just result in a particularly wicked bout of burping. (boy burps) The only danger there lies in the fact that some people might not
be able to belch enough to release the gas before
the pressure gets too much. In that case you might end up
with some nasty stomach aches or in a worst case
scenario, a small rupture, but that's pretty unlikely
because most people would vomit before that ever happened. Trying to gobble down the
Mentos and Coke at the same time and holding the mixture in your mouth will probably just cause you to spew out foaming
Coke all over the place. So no it won't kill you, but
it's still a stupid idea. (soft music) Why do we cry? Whether it's that one scene
in your favorite movie, overwhelming joy, or the crushing pain of
high school heartbreak, it's not hard to set us off
in a flood of salty tears, but why do we do it? Crying can be scientifically defined as the shedding of tears in
response to an emotional state. The non-emotional shedding of
tears even has its own name, lacrimation. It all has to do with
the biological process of the lacrimal system, which comprised of a secretory system that produces your tears, and an excretory system that drains them. When a tear is produced
from the lacrimal gland that sits in between
your eyeball and eyelid, you spontaneously blink, which spreads the tear across the eye as a thin film of liquid. Ever wondered why your
nose runs when you cry? That's because the tear
you have just produced usually drains neatly off,
down the lacrimal punctum, which is like a sink plug before
draining through your nose. But when you're having a real good cry, the lacrimal drainage system can't deal with the large incoming volume of tears, and they end up cascading
over your eyelids and down your cheeks. We actually produce three
different types of tears. These are known as basal,
reflex, and psychic tears. Your basal tears, keep your cornia and
nourished and lubricated, while reflex tears helped
to wash out any irritations from foreign particles or vapors. When you suddenly cry
while cutting onions, you are producing reflex tears. Psychic or crying tears
are the ones we produce in response to strong
emotions like sadness, anger, pleasure, or physical pain. These tears even contain
a natural painkiller called leucine enkephalin, which could explain why
people say a good cry makes everything better. Go forth and weep my bros. (soft music) Can you die from a broken heart? When beloved actress Carrie Fisher died on December 27th, 2016, the world went into collective mourning. But the tragedy was only doubled when her mother Debbie Reynolds also died suddenly the following day. At the time, the general consensus was that Ms. Reynolds had
died of a broken heart, but it's not even medically possible? The term heartbreak is used
to refer to the emotional and physical symptoms of
being, well, brokenhearted, but we all know that your
heart doesn't actually break, right? Correct. But the resulting stress
can be just as detrimental to your wellbeing. According to Australian heart
surgeon, Dr. Nikki Stamp, that kind of stress can
increase your heart rate and blood pressure, make
your heart work faster, make your blood sticky and
damage your immune system. And that's not all, when we
get caught up in heartbreak, it's easy to forget to
look after ourselves. Bingeing on comfort foods and
staying in bed for days on end is bound to have its own
negative implications. These symptoms may seem inconsequential, but there's actually a genuine
medical condition doctors use to refer to death by broken
heart, Taktsubo cardiomyopathy. In these rare cases, a
massive rush of adrenaline in an acutely stressful event can cause something
similar to a heart attack. The condition was first
described in Japan in 1990, after a patient's heart was said to resemble a Japanese
octopus pot called taktsubo. Not everyone who suffers
taktsubo will die, but it has certainly been recognized as a very real condition. So think about that, next time you break up
with someone via text. (soft music) What happens if you eat an
entire tube of toothpaste? After brushing your teeth twice a day for an entire lifetime, you must eat a whole load of toothpaste, but guzzling down on an
entire tube of the stuff is a one-way ticket to the ER. According to the US national
library of medicine, if you happen to swallow a
significant amount of toothpaste that crucially doesn't contain
the ingredient fluoride, you'll probably survive. As long as you Chuck a
load of water and milk and don't induce vomiting, the worst consequence you'll
face is a wicked stomach ache. Fluoride based toothpaste
on the other hand is a whole different kettle of fish. Fluoride, which is a
naturally occurring mineral is highly toxic in large doses. If you were to eat a whole
tube of fluoride toothpaste, you'd need to call the poison
control center immediately. A whole host of nasty side effects could include stomach
pain, intestinal blockage, conversions, diarrhea,
difficulty breathing, drooling, shock, tremors,
weakness, vomiting, and even heart attack. Basically you're about to
have a really, really bad day. Water or milk is a good
first line of defense, but you'll need to take a trip to the ER. Once you arrive there, you'll probably receive a
dose of activated charcoal to prevent the rest of
poison from being absorbed, calcium as an antidote to the poison and a bunch of tests and fluids, or you could just use
toothpaste like a normal person. (soft music) How long can you hold your
poop before you explode? Ever found yourself in a tricky situation where you realize you need to poop at the most inconvenient moment? Maybe you're trapped in a car during a long desert road trip, or you've just arrived at a
hot date's place for dinner. If you concentrate hard enough you even might be able
to hold it for so long that it feels like it has
disappeared altogether, but just how long should
you hold your poop? It might be a taboo subject, but pooping is essential to
help flush harmful toxins out of the body. After you eat, it takes
about six to eight hours for food to pass through your
stomach and small intestine. From there, it enters
your large intestine, AKA the colon for further
digestion, absorption of water, and finally the elimination
of undigested food. The colon is about five feet long and three inches in diameter, and it takes about 36 hours for food to move through the entire thing. All in all, it takes a grand
total of two to five days for food to be digested
and turned into poop, depending on the individual. It's not actually essential to go for a number two every day. In fact, the normal poop schedule can range from three times
a day to three times a week. but going several days without
dropping off any timber or deliberately holding it in, could cause all sorts of problems. When stool hits part of the rectum, it sends a signal to your brain telling you that you
probably need to unload. According to Niket Sonpal, an assistant clinical professor at New York's Touro College
of Osteopathic medicine, it's pretty hard to hold poop anyway, because you have to tighten the powerful
voluntary splinters. Even when you think your poop
has suddenly disappeared, there's a chance that may
actually have become impacted as you become more and more constipated. And the longer it stays,
the harder it gets. Eventually your stomach might
look permanently bloated as the pressure builds so much that it's impossible to hold flat. You'll probably need laxatives
to help relieve the blockage or in the worst case scenario, it may even need to be manually removed by a medical professional. Sonpal admits that he's never heard of anyone literally exploding or dying from fatal poop holding, but the embarrassment of
the removal should be enough to put you off. It's always nice when someone
puts a stool out for you, but not like that. Have you ever almost been caught short while trying your best to white knuckle in until a reasonable bathroom appears? Perhaps you had to hold it during an important business meeting, or your cousin's baby shower. Why not drop your most
embarrassing poop story in the comments below,
and I might even get back to the ones that make me laugh the most. Remember this is a safe space dudes. (soft music) Popping pimples is
actually a really bad idea. Picture this, you wake up
for your first day of school, stumble over to the mirror and freeze, staring right back at
you is a mountainous, bright red pimple. What do you do? Pop it of course. For many people, there's
nothing quite as satisfying as popping a ripe pimple,
but this news is just in, it's a really bad idea. You might be thinking but what about those professional
pimple poppers on TV? When performed properly, extractions can clear
certain types of pimples, but bad techniques combined with attempts to pick non pickable pimples can be a total recipe for disaster. You see acne is your body's
response to blocked pores and bacteria. The red bump you see on your
skin is actually the body's way of saying, Hey, I'm
doing something about it, leave it alone. When you pop a pimple, you're forcefully pushing the contents, bacteria, oil, and debris out of the bump, tearing the skin and creating
a fresh wound in the process. Instead of fixing the problem, it might even end up forcing
some of that nasty goop down, even further into the skin, which will only result
in an even larger pimple. Plus you're inevitably
introducing new bacteria and dirt from your finger
as you press on the Zed. As if all that wasn't bad enough already that oh, satisfying pop
could spawn more spots as the bacteria, oil, and debris is spread out onto the skin. All of these things can
also increase your risk of leaving a scar, which is
going to hang around far longer than the pimple ever would have. I'd stick to watching
pimple popping videos online from now on. (soft music) How long can you hold your
farts before you blow up? Farting is a fact of life. Well, we all know it isn't
considered acceptable in most social settings,
which means everyone has had to perfect the art of
holding one in at some point. At the grocery store, during class, walking down the aisle on
your wedding day, you name it, but how long can you
keep it all bottled up until the coat pops off? When your body needs to get
rid of natural gas buildup, there are two ways it can
come out, either as a belch (man belchs) or as flatulence that
escapes via the back door. (woman farting) Burping is usually caused by
something known as air aphasia, which results from the air
you swallow while talking or chewing gum. But farting is a little more complex. Sometimes bacteria or food
ferments in the stomach, leading to acidity and gas. (woman farts) People who suffer from
intolerances like lactose or gluten are also bigger farters, but even those with stronger stomachs can have trouble digesting
cruciferous vegetables like broccoli and asparagus. Believe it or not, you pass gas 10 to 20 times a day, sometimes without even realizing it. No matter how hard you
try to clench those buns, the flood gates will inevitably open when you get distracted by something else. Fart holding might not
be particularly harmful, but be warned any sort of buildup in your lower gastrointestinal tract will eventually push upward
and cause bloating, discomfort, and even trapped wind in your midsection. Exploding like a cartoon
character is also unlikely, but there is one exception
that refers to people with obstructions in their colons. According to Lisa Ganjhu an
NYU Langone medical center an obstructed colon can
blow up like a balloon because of the blockage to the point where it could even burst. To be on the safe side,
follow the age old advice, better out than in. (woman farting) (soft music) Humans are the only animals with chins. Now there's a conversation starter that's sure to make anyone's head spin. You know that knobbly
thing under your mouth? It's totally unique to us. Scientists had been scratching
their chins over the origins of the human chin for years, but it still remains a total mystery. The chin isn't just the
lower part of your face, it's a term used to describe
that little piece of bone extending from the jaw. It might think chimpanzees and gorillas, our closest genetic cousins have chins, but instead of poking forward like ours, their lower jaws slope down and back from their front teeth. Even other ancient hominids,
like the Neanderthals, like chins, their faces
simply ended in a flat plane. So what's it all about then? Over the last century, the ideas proposed by scientists to explain why we
evolved chins have ranged from helping us chew food to speaking. But James Pampush from Duke
university says otherwise. According to Pampush, the chin is in the wrong place to help reinforce the job for chewing. He also doubts that the
tongue generates enough force for the chin to be necessary
and helping us speak. Instead, the chin might actually be something called a spandrel, which is basically an
evolutionary byproduct left behind from some other feature changing. Perhaps the human face shrank
over time as our posture change and our face is shortened, or maybe it's a remnant from
a period of longer jaws. Now this banjo thesis isn't easy to prove because it's hard to find evidence to test if something is an evolutionary byproduct, especially if it serves no real purpose, at least it's there to rest
on when you're feeling bored. (soft music) How long can you hold
your pee before you burst? We've all found ourselves
in that awkward position where you suddenly
realize you need to pee, but the nearest restroom is out of order. Holding your pee in an art
form that takes practice, and the more you think about
it, the more you need to go. But just how long can you hold
on until you literally burst? The truth is how long can you
hold your pee varies greatly from person to person. It all comes down to bladder control. The bladder is the organ
that receives urine from the kidneys via thin
muscular tubes called the ureters. The bladder is muscular and expandable and it fills with urine as the kidneys continually
filter the liquid until it reaches full capacity. At that point, fibers that are designed to detect a stretch in
the bladder send signals to the brain, which say,
"Hey, you need to pee, buddy." When you finally reached the
restroom to relieve yourself, your brain tells the bladder to contract, which squeezes the urine, causing it to travel to the
urethra and out of the body. Your bladder actually
expands the chain size as you grow older. For example, the average person's bladder between the ages of 11 to 15 can hold 165 to 225 milliliters. But an adult bladder can hold
up to 300 to 400 milliliters of pee. Typically a person pees
about eight times each day and no more than one a
night after hitting the sag. How much and how often you pee
depends on how much you drink and other factors like convenience, but you should aim to go at
least every three to four hours. Basically you should never
intentionally hold your pee longer than you have to. Walking around with a full bladder could result in bladder dysfunction, risk of UTI or damage to the
urinary tract structures. In some rare cases, it's even possible for a person's bladder to rupture due to deliberate urinary retention. It's true what they say, when
you gotta go, you gotta go. (soft music) Does cracking your knuckles
really cause arthritis? It's a classic old wives tale. Don't crack your knuckles dear, you'll get arthritis like
me when you're older. Here's the truth, while cracking your knuckles
might aggravate the people around you, it certainly
won't increase your chances of developing arthritis. That oddly satisfying pop you hear, when you crack your knuckles, isn't anything cracking at all. The sound is actually
caused by bubbles bursting in the synovial fluid, which
helps lubricate your joints. When you pull the bones apart, either by stretching the fingers
or bending them backwards, the space between the joints increases that causes the gases dissolved
in the synovial fluid, bathing the joint to
form microscopic bubbles, that merge into larger
bubbles and get popped by additional fluid rushing
in to fill the enlarged space. Once the joints have been cracked, you won't be able to do it
again for around 15 minutes as the space returns to its normal size and more gases dissolve in the fluid, creating more bubbles
that are ripe for popping. But even if knuckle cracking
doesn't cause arthritis like your grandma told you, it's still a habit you
should think about ditching. While rare there have
been a few isolated cases of self-inflicted injuries like minor sprains caused
by knuckle cracking. But more than that, it's super irritating. But if you're not one to
care what others think, then crack on. (soft music) Blinking is more important than you think. Our body is such a
refined well-oiled machine that many of its processes happen without you even realizing it. Once such process is blinking, you might suddenly become aware of it now, but on any normal day, you probably blink
without even realizing it. Unless you're Hannibal Lecter, you'll likely blink every
two to three seconds, 28,800 times per day, each time for just 40 to
200 milliseconds at a time. But what's it all for? The main reason we blink
is to coat the cornea, the outermost tissue in the
eye with a layer of tears to keep it moist and free of
irritants that might damage it. Because blinking is a reflex so we have little control over it, it's hard to imagine what would happen if we just stopped blinking all together. Your corneas would
probably get painfully dry, which might even result
in some eyesight problems. There's a lot of coordination
that goes into blinking, but scientists are still
learning the details about what actually happens every time we briefly close our eyes. There even distinctive eye
movements called saccades that only happen when you blink. These movements realign
the eyeballs of obliquely along the field of vision, which means that when you
open your eyes after a blink, you're probably still staring at the thing you were looking at before. What's even more impressive
is what doesn't happen when you blink. Light doesn't dim,
images don't get blurry, and you don't lose focus. One study from 2012 even speculated that the brain uses blinks
to take many breaks. Ah if only each blink
actually felt like a nap. (upbeat music) Which of these incredible
facts changes the way you think about your own body the most? If you haven't quite fulfilled
your trivia fix just yet, why not stuff your brain
with more titillating tidbits by catching up on the other
episodes from this series. Thanks for watching guys. (soft music)
