Why Can't You Have Black Eyes + Other Body Facts

No human being has truly black eyes. Well, unless you get in a fight, but let's play nice, okay? Some of us do have a lot of melanin, so the eye might appear almost pitch black. But a lot depends on lighting conditions. In fact, those who are believed to have black eyes just have a really dark brown eye color. An eyelash is here to stay for 150 days only. The world record for longest eyelash was about 3 inches. You could whip yourself with that. Eyelashes are also home for tiny mites. The world's most common eye color is brown. There are loads of different shades of brown, but the fun thing is they're actually blue underneath. All blue-eyed people have the same ancestor as every other blue-eyed person in the world. Tears aren't just salty water. They're made of lipids, which is basically oil, water, and mucus. The salinity makes our tears antibacterial. The coolest camera so far has 200 megapixels. The human eye has 576 megapixels. That's why sunsets are so much better in real life than in photos. We blink about 4,200,000 times a year, at least once every 8 seconds. It would be cool if we were given a scent every time we blink. We would make more than $100 per day. It takes about a month for all your skin cells to renew. We shed about 30,000 dead cells every 60 seconds, losing about 8 pounds of skin each year. Our fingernails grow way faster than toenails. Toenails grow almost 4 times slower because they accrue less damage than fingernails. Even though we often stub our toes, a sudden circulation burst doesn't usually last long. A human produces from half a quart to 1 liter of saliva every day, depending on the person. That's enough saliva in a year to fill a bathtub. No spit! Saliva acts as a perfect remedy. Wounds in our mouth heal way faster than everywhere else. It also helps to taste food. Our taste buds are ready to perceive food only when it's dissolved by saliva. It may sound incredible, but our bones are stronger than they may seem. A cubic inch of human bone can bear about 19,000 pounds, making it 4 times stronger than concrete. Wait, is that where the term blockhead came from? The only thing that makes our blood types different is sugar. A, B, and AB types have sugars, while O has none, making it perfect for donors. No sugar doesn't make O type less sweet. In fact, it attracts mosquitoes even more than other blood types. People have only 8 blood types, while cows have 800 and possibly more. Holy cow! Usually, we shed about 50 to 150 hairs a day. An average lifespan of a hair is 5 years, and as soon as an old hair says goodbye to your scalp, a new one starts growing immediately. Human hair is stronger than the same diameter copper wire. A single strand can hold up to 3.4 ounces of weight, and if used properly, a full head can hold up to 18,500 pounds. Our stomach is bigger than it may seem, with a capacity of nearly half a pound in extreme conditions. The average is around 32 ounces. Food is digested within 4 to 6 hours, and it can also dissolve metal, so capacity matters. Lips are much more sensitive than fingers, having around a million nerve endings. That makes them 100 times as sensitive as fingertips. So, doing the math, I'm guessing that kissing is 100 times better than holding hands. Maybe? Grooves and furrows make our lip print unique, just like fingerprints. They also remain unchanged throughout our life. Your tongue print is unique too, by the way. Our belly buttons have an entire zoo in them, with a range of about 70 different bacteria. Some of them can also be found in soil in Japan, and even bacteria typically found at the polar ice caps. Yeah, right there, your belly button. Our bodies actually glow. Now, we can't see it with our regular eyesight, because the light we emit is 1,000 times less intense than the minimum level we can perceive. So, you'll have to trust me on this one. Humans are the only living things on Earth that can blush. It's provoked by an adrenaline rush. Carmon, used in blushes and lipsticks, is a red dye made of ground-up beetles. Our eyes keep growing throughout our lives. They sweat too, and earwax is actually a kind of sweat they produce. By the way, the nose never stops growing either. Especially when you're lying. The heart is the only muscle that never gets tired. The aorta is massive. Its diameter is almost as large as a hose in your garden. We emit about 500-1,500 ml of gases every day, which is enough to fill a small balloon. Hey, get the neighborhood together and fill up a blimp. It's worth a shot. Fat helps our bodies consume vitamins. Vitamins A, D, K, and E will absorb better when consumed with fat. Our bodies have enough fat to produce 7 bars of soap. Some parts of the brain can self-cannibalize, eating its own neurons and proteins if you don't provide them with enough nutrients. For example, the hypothalamus responsible for your sleep, hunger, and body temperature can do so. Believe it or not, you can't inhale and swallow at the same time. I know, you just tried. The pharynx is used as an air passage when you inhale, or as a food passage when you swallow. If you flatten all the wrinkles that your brain has, it would look like a pillowcase. When we're awake, our brain may produce enough energy to power an electric bulb. It has 10 watts of power. In your body, you carry enough bacteria to fill a can. Bacteria makes about 3-5 pounds of your weight, representing 2% of our total weight. Still, most of them are waste products. The average body temperature is a range of 97-99 degrees Fahrenheit. The highest fever ever recorded was a critical 115 degrees. A pinky finger may be the smallest one, but it's the strongest one too. 50% of your hand strength comes from your pinky. A human being has about 20,000-25,000 genes. Seems impressive, right? Still, cornflakes have more genes than we do. Cornflakes 1, humans 0. Luckily, it's about sophistication, not the quantity this time. We consist of many chemical elements, including iron. The iron in our bodies is enough to produce 3 nails, each 1 inch long. The carbon in our bodies can be used for 900 pencils. Your visual input changes because you need to blink. Plus, your head, eyes, and your entire body are always in some sort of motion. Your brain has to establish a mechanism that can create illusory stability. It automatically smooths your visual input. It doesn't analyze every little visual snapshot. It's like a time machine. You actually perceive an average of things you saw in the past 15 seconds at any given moment. The brain pulls together objects so they appear more similar to each other. That's why it tricks you into believing you're in stable surroundings. If your brain kept you updated in real time, the world would feel like a very, very chaotic place, with constant changes in movement, light, and shadow. Which would probably feel like you were hallucinating all the time. Your bones are really strong, but your teeth, which we also consider as part of the skeletal system, are even stronger. That's because of the enamel, the hard outer layer of your tooth. The enamel keeps the tissue and the delicate nerves inside your teeth safe. You're basically burning calories while you're thinking. When you rest and don't engage in any particular activity except for the basics, which includes digesting, breathing, and keeping yourself warm, it's the stage where your brain uses up to 20 to 25 percent of the total energy of your body. That means your body will burn around 350 to 450 calories per day while pretty much doing nothing. We're not the only ones in the animal kingdom with such a mechanism. Some small mammals like the minuscule pygmy marmoset and the tiny tree shrew devote the same percentage of their total body energy to their brain. Most of the energy the brain burns is to help its cells, the neurons, to communicate with each other. They do it via chemical signals the brain transmits across synapses, those special cell structures. So the brain directs a lot of energy towards synapses in order to make them work. Your brain never really rests. Even when you're sleeping, certain parts are active. So your brain needs its fuel to work, and you're basically burning calories in your sleep. The more demanding mental tasks you take throughout the day, the more calories you burn. So if you skip today's workout, solve some sudoku. Do you like to rush with your ice cream? Sometimes it pays off, but if you do it often, you must know the feeling of brain freeze pretty well. It's a pretty intense and uncomfortable feeling that comes from the front or sides of your head right after you drink or eat something cold, such as a slushy drink, ice cream, or an ice pop. Some people even go through a similar sensation whenever they're exposed to cold air. Scientists are still not sure exactly why this happens, but one of the theories is the cold substance stimulates a cluster of nerves located at the back of the palate. Another theory says the blood vessels in the roof of the mouth and sinuses quickly constrict because the temperature in your mouth drops before they dilate again. Brain freeze is not something dangerous that you should be seriously worried about. And no, hanging over the table, groaning, or clasping your head in your hands won't help much. Some people like to sleep a lot. Hey, guilty as charged. But some have a certain condition called familiar natural short sleepers, which means they're kind of immune to sleep deprivation. About one percent of our population has it. They can fall short on sleep and feel pretty good about it. They're fine with sleeping for six hours per night. This amount would wreck the majority of people after a couple of nights. The human eye normally has three cones. That means we can recognize approximately a million different shades in the green, red, and blue spectrums of colors. But there are some people with a rare condition, so-called tetrachromats, that have four cones in their eyes. This allows them to see ultraviolet shades, which means they can distinguish 100 million distinct colors. Did you know your skeleton is all wet? I mean, your entire body mostly consists of water, up to 60 percent. That fluid is not only in your organs, muscles, and skin. It's in your skeleton, too. Your bone mass is almost one-third water. There's this amazing hidden network a human body holds inside. Blood vessels are really small, but if you could line them all up, you'd get something huge. Your entire body boasts a network of 60,000 miles of blood vessels. One of the ways to keep your network healthy is by eating right. Have you ever wondered why our distant relatives, the primates, are so much stronger than us? In many ways, our bodies are very similar. Look at the chimp's muscle structure, for example. But our closest primate relatives are approximately 1.35 times stronger than us. The human body developed more slow-twitch muscle fibers compared to the rest of the primates. This type of muscle fiber is a less powerful one, but it lets us endure more than other primates and do things like foraging and hunting, activities that helped our distant ancestors to survive. That's also the reason why we can run a marathon. A monkey could never do it. But we'd still lose in a strength competition. Laughter is contagious. It's not just a metaphor. Researchers have found that strong emotions can make the brain activity of different people sink. Laughter is something science usually links with social creatures. People are almost 30 times more likely to laugh when in some social situations, hanging out with their friends or people they feel relaxed with. Most people have 12 pairs of rib bones, which means 24 ribs in total. But some have 25. One in 200 people is born with the so-called cervical rib. It forms right above the first rib and grows at the base of a person's neck, above the collarbone. A cervical rib can be located on the left, right, or both sides. You can have it without even knowing about it. This extra rib doesn't necessarily form completely. It can be just a thin strand of tissue fibers not even an x-ray can see. In most cases, it's really not a big deal, unless it starts putting pressure on nerves and blood vessels. You probably don't think that much when you're filling out a form and come across the eye color section. But it's not that simple for people who have this rare body feature called heterochromia. That's when a person has a difference in eye color. Complete heterochromia means you have two different colored eyes, like one blue and one brown eye. But there's also partial heterochromia. It means only a part of your iris is a different color from the rest. In the US, fewer than 200,000 people have it. Natural red hair is not as common as you might think. Only 2% of the world's population has it. There are eight genes responsible for it. Scientists used to link it with just one rare and recessive gene, MC1R, that you had to inherit in two versions from both of your parents. Then, they realized not every person with two red-haired versions got red hair. So, there have to be some other genes involved. Do you know which eye color is super rare? Gray. Most people have either brown, blue, or hazel eyes. About 17% of people have blue eyes, but the odds of getting those and red hair at the same time are just around 0.17%. Less than 1% have gray eyes. If you have gray eyes, it's because of a low level of melanin in the front layer of your iris. There are just 43 people in the world that have this extremely rare body feature called golden blood. About 0.6% of Americans are AB negative, but this is still not the rarest type in the world. In 1961, scientists discovered there's an indigenous Australian with a specific blood type, the type that completely lacks certain antigens, Rh, which means proteins or red blood cells. Those who have that exclusive type can donate to others with rare blood types but can receive it only from one of those other 40-ish people who have it. That's why it's golden blood. It's worth its weight in gold. Another rare body feature is a small hole near the ear, preauricular pit. At first, it seems like some sort of a gill. Some scientists have a theory it could be some sort of evolutionary remains from times when we were aquatic creatures. This tiny hole is mostly present near one ear, not both. Some people have chimp-like feet. They're bendy, flexible, and adapted for climbing trees. Researchers at Boston University filmed 400 people walking barefoot and concluded that 1 in 13, or 8% of the participants, had this feature. Typically, the human foot is rigid. We've evolved that way so we can efficiently walk on even terrains. At least, that's something you could learn from textbooks. But other apes have flexible feet. This allows them to grasp branches as they move through the trees. The kind of foot that's similar to tree-dwelling apes is flexible at the middle. It bends at the ball of the foot and is halfway between the ball and the heel. Human feet normally have a joint at this point, but the majority of people have stiff ligaments that span the joint. That's how they keep it rigid. Those rare people with chimp-like feet have softer ligaments that allow their mid foot to bend. Try to move your middle finger or your pinky. It's hard to do without bending your ring finger, right? Well, that's how it works for most people. But there's some who can completely isolate their ring finger. Researchers believe it's hereditary. If you can touch your nose or chin with your tongue, it means you stand with around 5% of the world's population that can do that. Most people's tongues won't reach that far out, no matter how hard they try. Some women have super color vision. With this, you're able to see and distinguish colors thanks to special cells in your eyes called cones. People usually have three types of cones, but scientists are especially interested in tetrachromats. They believe these people have four types of cones. Thanks to that, they're able to see 100 million different colors. One research team from New Castle University spent years searching for such people. Finally, in 2010, they found one of them. It sounds like a magic power at first, but it's not always fun. One tetrachromat said going to the grocery store can be a real nightmare because it's like seeing a trash pile of colors coming in at every angle. There are people born with a double row of eyelashes, a condition known as That extra row emerges from the ducts of my bowmian glands. One of the celebrity examples for such a rare genetic mutation was Elizabeth Taylor. Here's something you can try. Move your right foot off the ground. Go in a clockwise direction. Can you draw the number six with your big toe? No pencil or paper allowed, just your toe. The majority of people will soon notice they've started moving their foot in the opposite direction without even realizing it. This partially happens because the number features a counterclockwise circle. Only in some rare cases, when either the brain is wired in a different way or thanks to practicing, can some people do it the other way around. Now, on average, the heart is as big as your fist. It beats 115,000 times and pumps around 2,000 gallons of blood each day. The right lung is bigger than the left one because your body needs to make some room for the heart. You inhale a lot of different types of debris, including 7,000 of your very own skin flakes, and that's only in a day. The stomach is the most important defender of the immune system. Hydrochloric acid in our stomach kills dangerous food toxins, viruses, and bacteria that get in there with the food you eat. This acid can digest even the stomach itself, but the mucous membrane protects it. You can burn calories when you take a hot bath as many as you would if you took a half-hour walk. You burn somewhere between 100 and 200 calories per hour while standing. Sitting burns 60 to 130, depending on your height, weight, gender, and age. Now, your own body makes mosquito bites swell and itch. A mosquito breaks your skin. Your immune system perceives the insect saliva as a foreign substance, so it starts a special reaction to flush the intruder out of your body. A compound produced by the immune system, called histamine, makes the blood flow faster around the bitten area, and it causes swelling. The histamine also sends a signal to the nearest nerves, which makes the bite itch. Meanwhile, the food on the plane is likely to taste different than on the ground. That's because you lose up to 30% of your tastebud sensitivity due to the dryness and pressure in the cabin. It's especially true about salty and sweet foods. Now, you wouldn't be able to taste food without saliva. Your tastebuds have chemoreceptors that recognize different flavors, but they need some liquid for those flavors to bind into their molecules. Also, you can't taste things saliva doesn't dissolve. You can always squeeze in some dessert, no matter how much salad, soup, or meat you've eaten before. Your body gets bored of savory tastes, but when you see and smell something sweet, like ice cream, cakes, or chocolate, your brain gets excited. It overrides all fullness signals for pleasure. Plus, your stomach is a flexible organ, and sugar helps it relax and physically make room for dessert. Hey, I rely on that information! The tongue is one of the strongest muscles in your body. This organ contains more than 10,000 tastebuds, and each bud is filled with microscopic hairs. Their job is to sense your food, distinguish tastes, and send information to your brain to initiate the appropriate digestion process. During your life, all those tiny bumps and ridges on your tongue create a special individual pattern. That's why experts say that tongue prints are as unique as fingerprints. Your tongue doesn't have separate bitter, sweet, sour, or salty sections for tasting. Each of the 8,000 tastebuds you have on the tongue, the roof of the mouth, and even in the throat can detect all the tastes. For some people, cilantro may taste similar to soap because the plant contains a chemical used in soap making. But only 4-14% of the world's population have special genes that can detect it. The masseter is the strongest muscle you have based on its weight. Together with the rest of the jaw muscles, it can close your teeth with a force of 200 pounds on the molars and 55 pounds on the incisors. Your spine has a great memory. It remembers your posture, making it so difficult to change it for the better. You owe goosebumps to your ancestors from many, many, many years ago. Their hair used to stand up to make them look bigger and scarier to foes. Cats hiss and arch their backs for the same reason. Only about 43% of you is actually you. Over 50% of the cells in your body belong to tiny little creatures that mainly live in your gut. Still, even though your own cells are fewer than the microbial ones, there are, on average, about 100 trillion of them in you. See, you're not alone! With this in mind, your own genes are less than half of what you really consist of. If you take all the microbes dwelling within your body and count their genes, you'll find between 2 to 20 million. Our height, the shape of our body, and skin color depend a lot on where our ancestors used to live. But we can adapt to new conditions even within our own lifespan. For example, if you move from the plains to the mountains, you'll eventually develop more red blood cells to compensate for the lack of oxygen. And naturally, if you move from a colder climate to a hotter and sunnier one, your skin will get darker to adapt. Our lifespan is programmed within our cells. They constantly review and divide, but they have a sort of internal timer that stops at some point. Some cells also stop reproducing sooner than others. On average, cells cease dividing when we reach the age of 100, if we're that lucky. That means that if we could find a way to trick our cells into turning off the timer, we could potentially live forever. And move in with our grandchildren! A human mouth is pretty unique. You won't find two identical sets of teeth even among identical twins. That's because the shape depends on how each person is using their jaw. Even the tiniest habits you used to have many years ago, such as lip-biting, affect the formation of your teeth and the uniqueness of your dental impression. You've probably noticed that lipstick prints on a napkin or a mirror are always slightly different depending on who left them. Alright, who left the lip prints? Studies of both females and males revealed that lip print patterns for each individual are unique. They didn't reveal any special traits based on the gender factor. The mandible, or the lower jaw, is the only skull bone that isn't fixed to the bone around it. You know what, in 10 years from now, you'll be a completely different person. Well, at least your skeleton will be. To reach its adult size, your skeleton went through a process called modeling, which means the development of growth and formation. Turns out it regenerates completely once every 10 years or so. This entire process ensures you always have healthy bone cells, which can support you and provide calcium to your body. And speaking of ways the body regenerates, every second you make 25 million new cells. I'll do the math for you. Okay, that means in about 15 seconds, you'll have made more cells than there are people in the United States. Think about that the next time you feel you haven't been productive enough. Some animals have eyes that need to adapt to hot climates, like camels, for example. Their eyes feature a third eyelid, but these sweep across from the corner of each eye. Because their environment is filled with small particles, they need to clean their eyes more frequently than other species. Now, see that little pink thing in the corner of your eye? It's also a third eyelid. Well, a vestige at least. In humans, the third eyelid is unnecessary because it no longer serves its original purpose. Next time you're tuning into your favorite song, try to pay some attention to your heartbeat. If you listen closely, you'll notice that sometimes your heartbeat may synchronize with the rhythm of the song. Now, not all genres of music have this special ability, but some tunes trigger the release of dopamine, or the happy hormone. This effect may give you a lower heart rate, breathing rate, and blood pressure. And speaking of that healthy ticker of yours, just in case you're wondering, it beats on average about 75 times per minute. This means each year, a human heart can pump enough blood to fill an Olympic-sized pool, if that were a thing. What's even more fascinating is that if you were to connect all your blood vessels end-to-end, it would be able to circle the Earth two and a half times. But that's not good for your own health, so don't do that. Your heart can also continue to beat even if it's removed from the body. That's because it has its own internal battery, which allows it to beat as long as it receives oxygen. If you regularly have your nails done at a salon, you've probably noticed you need more appointments for your fingers than your toes. That's because fingernails do grow faster. The definitive scientific answer is still up for debate, but many specialists think it's because fingernails used to be claws, somewhere back in our ancient history. These days, they're flatter and have widened a bit, and it all happened when primates started using tools in their day-to-day lives, like stones and branches, so there was less use for claws. Once they got flatter, it meant nails wouldn't have gotten in the way if primates wanted to use the palms of their hands. As for why fingernails grow faster than toenails, the short answer may be the fact that we use our hands more than your feet. As such, our fingernails are more exposed, and we may have evolved to grow them faster. The more you use a certain part of your body, the more it becomes exposed to damage. So for me, I'm in danger of my mouth falling off. Getting back to our hands, it's about time we give a nice shout-out to our humble pinkies. We don't see them as being really that important, since we don't use them for holding objects, eating, or writing. But recent studies have shown that losing the pinky on our dominant hands would have a devastating effect. Specialists haven't gathered enough data to supply specific numbers, but from what they've learned so far, losing our pinky would weaken our grip strength considerably, even if it's the lesser-used finger. Adding the ring finger to that, and the effect would be worse for our grip strength. Another recent study done in the UK has shown that only about 40% of people are happy with how their nose looks. Regardless of how you feel about it, the human nose is a real-life superhero. That's because it acts as a heater, filter, and humidifier all at once. Inside each nostril, there are small, shelf-like bones that feature blood vessels. They heat the air up before it reaches other parts of our respiratory system. The mucus that's inside there handles making the air more humid. As for the filtering part, that's why we have nose hairs. Small particles get stuck on these small hairs, which helps prevent pollen, spores, viruses, or bacteria from reaching our lungs. Now, when watching cartoons, we're led to believe that the sound our heart makes is because it's touching its environment while beating. Well, it turns out that sound is actually made by the opening and closing of the heart valves. They're like small doors inside our hearts that open and close to pump blood correctly from one side of the heart to the other. For our bodies to work, blood needs to move at the right time and in the right direction, or else. Now, let's talk teeth. Throughout your entire life, you'll probably spend up to 40 days total just brushing your teeth. And in case you're still wondering, teeth are not in fact bones, even though they do have a lot in common. One of the primary differences between bones and teeth is that our bones can regenerate – they are living tissue. Our teeth are not, and they remain permanently damaged once broken. Here's another shocker. We are the only species on this planet to have a chin. There's still some debate about this subject in the scientific community, but one of the reasons why seems to be to make our jaws stronger. As humans have continued to evolve, their teeth and the muscles in their jaws got smaller and smaller, so they needed something to help with increased jaw resistance. Now, most of us have developed some specific traits depending on the area of the globe in which we live. But there is a group of people, specifically those who live in higher altitudes, that develop some pretty cool traits. That's because high-altitude environments come with less oxygen. Not only do these people survive in these locations, but they've adapted so well that they actually thrive. In the Andes Mountains of South America, people have evolved red blood cells that can carry much more oxygen. It makes their overall circulatory system much more efficient. Here's a young man in a business suit. He's got a secret. He's in the bathroom standing in front of the mirror, washing his face with cold water to cheer up. There's no one else here besides him. But he's not alone. The guy looks nervous. He slaps his cheeks, looks in the mirror, and says, don't worry, we can deal with it. We've been going to this for so long, we will win. He said we, not because he has a split personality. And no, he's not talking to someone else through a small microphone. He said we, because he knows a secret. Technically, he's not all human, but a group of billions of living creatures. Him, you, and all the people on Earth aren't really who they think they are. Only 43% of your body is made up of human cells. The remaining 57% are microbes and bacteria. Now this guy is going on stage to tell us this secret. Get on the scales. See the number? Now subtract a little more than half from it. This is your actual weight. Everything else is microscopic organisms. It's hard to believe because, in this case, your body should constantly change its shape, disintegrating into tiny particles. You would see your skin pulsating and continually moving. Fortunately, this doesn't happen for two reasons. Firstly, microbes are tiny. Their movements aren't visible. Secondly, most of this microbial world is in a dark place we can't see. A place without access to oxygen. In our intestines. It's where billions of little creatures are roaming. Feeling kinda crowded, huh? Some of them appeared before we were born, but most were colonists who came with food and water. On your body's surface, all microbes come from the environment. Every corner of your skin is covered with microbes. No matter how you try, it's impossible to get rid of them. There are more microbes than human cells. Our genome consists of about 20,000 genes. The number of microbes genes in the human body is about 2 to 20,000 million. That means that, technically, we're not people, but microbes. Fortunately, it's not so bad. The genome of microbes complements our own. Such a model of existence reveals many opportunities for medicine. The human microbiome includes bacteria, fungi, and other microorganisms. All of them divided into many species, and each type performs its own functions. Some microbes are responsible for vitamin extraction from food. Others help the breakdown of destructive substances. Another type helps your tummy digest food. A separate group regulates your immune system, protects it against ills, parasites, and viruses. Some control weight. Simply put, microbes make your life better, help your body function, and affect your health. There are microorganisms that provoke many diseases. They impair immunity or affect vital organs. Imagine you know exactly which bacteria are responsible for feeling unwell. Next, you find a way to rid yourself of them. It can be some pill with poison against those microbes. You drink it, and the cure erases all the harmful pests inside your body. A disease might appear because of the lack of beneficial microbes. This is one of the ways doctors heal many people in the world. Now let's say you've determined a group of microbes that help strengthen muscles. Then, you find out which trace element helps these bacterias work faster and more efficiently. You add this vitamin to food or just get a pill containing a billion of these microbes. As a result, your muscles grow twice as fast. The presence of some microbes or the lack of others can show the state of your entire body. A sample of your microbes can indicate your level of health or the presence of some disease. Any person can improve their body not only with the help of genetic engineering but with microbial medicine. Studying human microbes is cheaper, more efficient, and faster than expensive complex gene modifications. This area is just beginning to develop all over the world, but there are already some discoveries. Previously, humanity thought microbes were enemies. We made up many ways to destroy bacteria and viruses. But along with the harmful germs, these cures get rid of the good ones. Now scientists understand that microbes can both take away and save lives. So they started large-scale research on this subject. Let's have a look at a big panda. This animal with an ample supply of fat under its skin is omnivorous. It rarely eats meat. Its diet mostly consists of berries and bamboo shoots. But in winter, there's none of this, so pandas feed on bamboo leaves. That food is low-calorie, there's almost no proteins in it. But still, pandas don't lose weight after a cold winter. Recently, scientists found out how pandas do that. It's all thanks to a unique microbiome. Every winter, a lot of unique bacterias are born in their intestines. These microbes extract and synthesize helpful substances from bamboo leaves better than others, and thus preserve the panda's weight. Scientists put these bacteria inside field mice. Small rodents began to gain weight much faster. Hamburgers, cakes, and other heavy foods contain calories and help develop colonies of microbes that contribute to weight. Millions of species of microbes have millions of functions. In theory, each of these functions can be used for the sake of humans. So, imagine you need to lose or gain weight, and you just add these microbes to your lunch. Do you want to sleep better or fight drowsiness? Drink microbes that will affect the production of sleep hormones. Do you want to strengthen the bone tissue? No problem! Bacteria are not only inside our bodies, they're everywhere. Part of the planet is made up of microbes. These tiny organisms are constantly multiplying. Look, there are a trillion of them on your keyboard. One bacterium increases in size and splits into two bacteria. After a few minutes, these two increase and divide again. Four microorganisms appear. Each of them splits in two. The colony of bacteria is rapidly growing. With such quick reproduction, one microbe can make one ton of offspring in just 24 hours. After 5 days, bacteria will fill all the seas and oceans. They will weigh more than the whole planet. Under ideal conditions, bacteria could take over the whole world. However, this will never happen. There are no such perfect conditions for uncontrolled bacterial growth. The speed they multiply at is equal to the speed of their destruction. Dryness, water, light, high temperature, gases, humidity, all these phenomenon help control their population. At the same time, microbes are in charge of most of the chemical reactions on Earth. An old apple on the ground is rotting because of germs and bacteria. Mold forms on bread because of microorganisms. But they don't just exist and affect the condition of any material and other living creatures. An endless battle for survival continues in the world of microorganisms. Giant bacteria absorb smaller ones. Microbes with spikes defeat long microbes. There are also viruses that penetrate bacteria and infect them with their cells. A small ball with a virus can destroy an entire colony of microbes. Okay, think about it. We are the only animals on the planet who have a chin. Just as humans. Primates don't have it, and even our close extinct relatives like Neanderthals never had it either. Not by the hair on their chinny chin chins. Scientists have a couple of theories on why people have chins. First, it could be there to help us chew food because that extra bone might mitigate stressful mechanical actions like chewing. But if we really needed that kind of support while chewing, we'd probably have more bones on the inner side of the jaw, somewhere near the tongue instead of beneath the jaw. For example, chimpanzees have an additional bone in their lower jaw placed on the tongueward side, something we don't have. Second, we might have the chin to speak easier. Some scientists claim that extra bone below provides some kind of reinforcement. However, we don't use that much force when speaking. Well, some of us do. Third, some researchers say our chin could be something that measures attractiveness when we seek a partner. Hey, nobody can take it on the chin like us humans! Also, the chin could be a result of our skull getting smaller. This is why our mandibles are not as robust as those of our extinct relatives. As they developed, discovered fire, and started cooking their food, they no longer needed strong jaws because the food wasn't so difficult to chew anymore. Elephants have something similar to our chin. But their so-called chin is there because they have a large lower lip, plus a lack of lower teeth. It's not some type of bony protrusion that we have. So, chin up, kiddo, stay on the bright side! Meanwhile, our cells are so small that if you could get 10,000 of them together, they could fit on the head of a pin. The human brain has an impressive memory capacity. The brain has around 100 billion neurons. You'd need more than 3,000 years to count all of them, so trust me. If we could store one memory on each neuron, our brain would eventually run out of space, and we'd have limited storage space, like on a USB flash drive or an iPod. So yes, it would be possible for our brain to be full. Not mine. Neurons are linked to each other. Each has 1,000 connections to others. That way, our memory capacity is exponentially getting bigger. It's hard to measure it, but it could be millions of gigabytes. If our brain was a digital video recorder, it could record 3 million hours of your favorite shows, and you'd have to leave the television on for over 300 years to do that. Whenever we laugh, think, look at something, dream, move, or do some other activity with our body. Small electrical and chemical signals run between neurons along those connections. Our brain is always active, and sometimes, it's even more active when we sleep than when we're awake. By the way, neurons make and send more information than all the phones in the whole world. Just one neuron won't generate that much electricity, but all of them together produce enough of it to power a light bulb. Our brain is a wrinkly organ, but if you could open up your head, remove it, and smooth it out, it would lay down flat in the size of an average pillowcase. Whenever an insect lands on your leg, your skin's sensory neurons quickly send a message to your brain at an impressive speed, 150 mph. The brain sends back a message for your leg to shake the insect off even faster, at around 200 mph. Our heart beats more than 3 billion times in the average lifetime and pumps over 47 million gallons of blood. Humans have unique fingerprints. So do koalas, chimpanzees, and gorillas. Other than fingerprints, people have a unique tongue print too. And they have a chin. We are the only animals that sleep on their backs. Also, humans are the only creatures that can draw straight lines. And we have a chin. More than 50,000 of your body cells were replaced by new cells in just a few seconds while you were watching this part. Didn't you notice? Yes, our entire body regenerates. But teeth are the only part that can't heal themselves. Left-handed people mostly chew food on the left side of their mouth, while right-handed people do that on the right. And in each case, we move our chins. Our fingers are very sensitive, but lips are even hundreds of times more. Plenty of animals can move their ears to find a sound source around them, but most people can't move their ears at all. Your left lung is around 10% smaller than the right one because it needs to allow some space for your heart. Aww. Also, it can fit in less air. Your lungs have 1,500 miles of airways and more than 300 million alveoli, which could cover approximately one-quarter of a tennis court. Lungs are the only organ in our body that can float on water. Toenails grow around four times slower than your fingernails. It happens because we do more things with our hands than our feet, so we cause more trauma to our fingernails. Muscle is a word that was originally a Latin term, which means little mouse. When ancient Romans would flex their bicep muscles, it reminded them of a mouse. Heh, my biceps look like little hamsters. Our brain takes and uses more than a quarter of the total oxygen our body receives. Each of us has more microbes than there are stars in our galaxy, trillions and trillions of them. There are billions of bacteria only in our mouth, and over 2,300 types of bacteria in our belly button. Ew. But they're all so tiny that if you could put all the microbes from our body together, they'd weigh as much as your brain, around 3 pounds. There's a high possibility your right hand has different types of microbes than the left one. It happens because they cover our skin from head to toe, and their variety depends on our skin thickness, humidity, temperature, texture, and chemistry, which can change as we use our right and left hand in different ways. That's it for today! So, hey, if you pacified your curiosity, then give the video a like and share it with your friends! Or if you want more, just click on these videos and stay on the Bright Side!