101 faits aléatoires étrangement fascinants
Vous êtes-vous déjà demandé quels sont certains faits totalement déjantés qui vous stupéfieront ? Eh bien, nous avons ce qu'il vous faut avec cette vidéo ! Elle est remplie à ras bord de 101 petites informations aléatoires qui sont sérieusement étranges mais tellement cool. Des comportements animaliers originaux aux pépites historiques époustouflantes, il y en a pour tous les goûts. Attention : ces faits pourraient changer votre façon de voir le monde, alors regardez avec prudence. Animation créée par Sympa.
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Musique par Epidemic Sound https://www.epidemicsound.com
Pour ne rien perdre de Sympa, abonnez-vous!: https://goo.gl/6E4Xna
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Nos réseaux sociaux :
Facebook: https://www.facebook.com/sympasympacom/
Instagram: https://www.instagram.com/sympa.officiel/
Stock de fichiers (photos, vidéos et autres):
https://www.depositphotos.com
https://www.shutterstock.com
https://www.eastnews.ru
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Si tu en veux encore plus, fais un tour ici:
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FunTranscript
00:00 When an astronaut returns to Earth after a stay in space,
00:04 he is usually a few inches taller than he was before leaving our planet.
00:09 Your body acts in an unusual way when you free yourself from gravity.
00:13 Without all the weight that compresses the cartilage of your spine and your joints,
00:18 your body stretches a little in weightlessness conditions.
00:21 But it doesn't last forever.
00:23 The effect disappears after a while.
00:25 A similar phenomenon also occurs on Earth.
00:29 When you lie down for a good night's sleep, you become a little taller.
00:33 Not more than a centimeter, but still.
00:35 That's why you're taller in the morning than at the end of the day.
00:38 There is a mushroom with a strange appearance.
00:41 The Idzinel de Peck, whose hat looks like it's bleeding.
00:44 No wonder it's nicknamed the bloodthirsty mushroom.
00:48 Under its hat are also scary thorns that look like crows.
00:52 This mushroom is not really delicious.
00:55 It tastes like a very bitter pepper.
00:57 The highest tropical tree in the world reaches 100 meters high and weighs more than 82,000 kilos,
01:02 which corresponds to the weight of an average airline.
01:05 It grows on the island of Borneo in Malaysia.
01:08 The view from the top of this tree is amazing.
01:11 This is what a local climber discovered by climbing the tree to measure it correctly.
01:16 It seems that the oldest known star is older than the universe itself.
01:21 It is called Methuselah and is located 190 light years from our planet in the constellation of the balance.
01:28 By analyzing the data on its brightness, size, structure and composition,
01:34 scientists have realized that the star was probably about 14.5 billion years old.
01:39 There could be 800 million years of difference between the real age of the star and the one their research has shown.
01:46 But if the star is really older than the universe,
01:49 it could mean that the Big Bang may not be the time when it all started.
01:54 The smallest mammal in the world is this tiny and adorable animal called the Burdon bat or Kitty porcupine.
02:02 Its nose looks like the tail of a pig and its eyes are tiny and barely visible.
02:07 These creatures are barely more than 2 centimeters long and have a width of about 18 centimeters.
02:14 Your nose, your toes, your hands and many other parts of your body can freeze.
02:19 But your eyeballs can easily withstand the cold, even if you leave them completely unprotected.
02:25 When people wear glasses or masks, it is mainly to protect their eyes from the wind or snow reflections,
02:31 and not from the frost, whatever the temperature.
02:34 Indeed, unlike other parts of your body, your eyes are fed with hot blood at all times,
02:40 even in the coldest environments.
02:42 They are covered by many blood vessels that constantly heat them up.
02:46 In addition, they are located at the bottom of your head, where fat, tissues and bones help keep them warm.
02:52 It is almost impossible for the eyes to freeze as long as the rest of the body works.
02:57 There are three reasons why curly hair is, well, curly.
03:01 First, the follicle from which a strand of curly hair grows has an oval shape,
03:06 unlike the circular follicle, which results from straight hair.
03:10 Secondly, a strand of curly hair comes out of the surface of the skin
03:14 forming a sharper angle than straight hair, which makes it curve as it grows.
03:19 Finally, the shape of curly hair promotes the formation of chemical bonds between the proteins of the same strand,
03:25 which makes the hair even more curly.
03:28 The famous "Piece's Tower" is tilted because of the floor that is under the base of the building.
03:33 It was probably frustrating for the people who built it.
03:37 But this floor is also partly an element capable of protecting the tower from possible earthquakes.
03:43 Because of the floor and its height, the tower does not vibrate with the shaking of earthquakes.
03:49 So, the reason why the tower is tilted is also the reason why it always stands.
03:55 Giant squid have the biggest eyes you can find on Earth.
03:59 They are 28 cm in diameter, which is bigger than a table plate.
04:04 The "Crystalline", meanwhile, is as big as an orange.
04:07 The ocular globes of giant squid are filled with water.
04:10 Giant squid are really massive and can reach 13 meters long.
04:15 You are a fan of chocolate, but you would like to start eating healthier and replacing it with fruits?
04:20 Then you will be happy to learn that there is a fruit that tastes similar to chocolate cake.
04:26 It is the "Black Sapote".
04:28 It is a species of khaki, native to South America and Central America.
04:33 When the fruit is ripe, it is like eating a sweetened cream with a cocoa soup.
04:38 When you browse an old book or an old newspaper, you are likely to see that the paper has turned yellow.
04:44 The paper is made from wood, which is mainly made of white cellulose.
04:49 Wood also contains lignin.
04:52 It is a dark substance that is also found in paper with cellulose.
04:57 Lignin is like glue that binds cellulose,
05:00 which allows trees to stand up and make the wood stiff.
05:04 When you expose lignin to sunlight and ambient air, the paper turns yellow.
05:09 Light travels much faster than sound waves.
05:12 The speed of light is the maximum speed at which certain information can move from one place to another.
05:19 Light travels in space at a speed that nothing can really surpass.
05:23 Especially not sound, which does not even exist in space.
05:26 When museums do not allow you to take pictures,
05:30 they are afraid that flash cameras will damage the paintings and damage their pigments.
05:35 Some pigments are more sensitive to light.
05:38 This means that the chemical reactions that degrade the pigments accelerate when they are exposed to light.
05:44 This is why lighting in galleries and museums is so carefully controlled.
05:49 If you don't want to go extinct, press the edge of your nose with your fingers.
05:54 By doing this, your brain receives an alarm signal.
05:57 Very quickly, it will stop all other processes, including the reflex to go extinct.
06:02 The longest extinction crisis was recorded in 1981.
06:07 Achoo! Sorry.
06:09 It lasted 976 days.
06:12 It was a woman from the United Kingdom who went extinct more than a million times.
06:16 The part of your brain that is responsible for sight is behind your head.
06:21 It is interesting to note that the right side of your brain controls the left side of your vision and vice versa.
06:27 If you are in a noisy place, like a nightclub or a concert,
06:32 move your ears to better hear your friends.
06:35 Press the tragus of your ear, the cartilage bump covered with skin located in front of the auditory canal.
06:41 Then orient this ear to your friend.
06:44 If you feel nervous, close your fist by letting your thumb go over and breathe gently on it.
06:51 If you can't stop a hockey, put an ice cream on your tongue.
06:55 You can also cover your ears with your hands and drink a glass of water at once with a straw.
07:00 Pulling your tongue or raising your arms to the ceiling can also work.
07:04 When a person snores, the sound usually does not exceed 60 decibels.
07:10 It is the sound of a normal conversation.
07:12 But sometimes the sound level can reach 80 decibels.
07:16 It is the sound of a mixer running.
07:19 If you want to wake up faster, hold your breath for a while.
07:23 By doing this, your heart will start beating faster and your body will activate faster.
07:28 But don't overdo it because if you wake up too quickly, you will impose unnecessary stress on your heart.
07:34 If you feel bad mood, squeeze a pencil between your teeth.
07:38 The muscles involved in the smile will be stimulated.
07:41 This will send impulses to your brain which will begin to secrete endorphins.
07:45 In a blink of an eye, your smile will become much more sincere.
07:49 Right-handed people tend to chew most of their food on the right side of their mouth.
07:54 And left-handed people use their left side more.
07:57 The smell of the sea bass can activate your super memory.
08:00 If you have to learn something by heart, make it lie in your bed with a bunch of sea bass next to you.
08:06 This will help you memorize information more efficiently and faster.
08:11 If you have a leg asleep, shake your head.
08:14 After about a minute, you will realize that your muscles have relaxed and that the feeling of tingling has passed.
08:21 The muscles that move your eyes do about 100,000 movements a day.
08:25 If you wanted to move your legs muscles as many times as you want, you should walk 80 km.
08:30 Deja vu could be a kind of brain delay.
08:35 According to a theory, this could happen when the brain transfers information from one hemisphere to the other.
08:41 If there is any delay in this process, your brain receives the same information twice.
08:46 And it then treats it as an event that has already occurred.
08:50 Among all the people who can move their ears, only 30% manage to move one.
08:56 If your mouth burns when you eat pineapple, it's because while you eat this fruit, it eats you too.
09:02 Pineapple is the only known food that contains bromelain, an enzyme that breaks down proteins.
09:08 Fortunately, gastric acid destroys it.
09:11 If your throat itches, scratch your ear.
09:14 This stimulates an air that causes a muscular spasm in your throat.
09:18 In a blink of an eye, the itch will disappear.
09:21 Surprisingly, we burn more calories by sleeping than by watching TV.
09:26 Ask a friend to sit on a chair and put a finger on his forehead.
09:31 Then tell him to get up without using his hands. He won't make it.
09:35 Just like salamanders make their tails grow back, humans are able to regenerate cartilage.
09:40 It's the rubbery substance that surrounds our joints.
09:43 Scientists have recently discovered that cartilage can repair itself.
09:48 This process would be most effective at the ankle level, but much less at the knee level and even less at the hip level.
09:56 If you are lying in bed and suddenly feel dizzy, put one foot on the ground.
10:01 Your brain will receive the information that you are holding on to something firm, and this unpleasant sensation will go away.
10:08 Only 30% of people can dilate their nostrils.
10:12 If someone hits you in the back while you're tired, they ask you to let go of them.
10:18 People with a single transverse palmar fold are very rare. They are 1.5% in the world.
10:24 Most people have two palmar folds.
10:27 Men are more likely to have a single fold than women. In most cases, this condition is hereditary.
10:34 Your gastrointestinal tract has a very short life cycle. It doesn't live more than 10 to 14 days.
10:40 Your lips are hundreds of times more sensitive than the tip of your fingers.
10:45 If your skin wrinkles when you stay in the water for too long, it's not because it absorbs water,
10:50 but to allow your fingers and toes to take better hold.
10:54 Studies have shown that the palmar fold acts as a re-initialization for the nose.
10:59 This reactivates the cells that cover the inside, which are called cellular cills.
11:05 If a person suffers from anosmia or olfactory cystitis, they don't smell.
11:11 The amount of food you eat throughout your life will weigh as much as eight Asian elephants.
11:16 No wonder people spend nearly four years of their lives eating.
11:20 Your skin analyzes one million bits of data per second.
11:24 Your ears and nose process 100,000 bits each, and your tongue is the least productive.
11:29 It only analyzes 1,000 bits.
11:31 Being really multitasking is actually impossible.
11:34 What we call multitasking is actually the very fast transition from one task to another in our brain.
11:40 In this case, people tend to make more mistakes, and it takes twice as long to do each task.
11:47 On the other hand, when you do a physical activity that you've already done several times,
11:52 you can do a mental task at the same time.
11:55 That's why you can easily run or take a shower while thinking.
11:59 If you see someone pulling on their sleeves non-stop, they're probably feeling very nervous.
12:04 Tossing an object is a self-calming mechanism.
12:07 You can check how unique you are by chewing a sprig of coriander.
12:12 For some, this aromatic herb tastes similar to soap,
12:15 because this plant contains a chemical compound used to make it.
12:20 But only 4 to 14% of the world's population has the gene capable of detecting it.
12:25 Are you one of them?
12:27 An adult uses about 200 muscles to take a single step.
12:32 Your eyes move non-stop when they process information.
12:35 Otherwise, you wouldn't be able to see an image as a whole.
12:39 These movements go unnoticed because your brain is an excellent video editor.
12:43 It stabilizes images and links tons of fragments into a single fluid video.
12:48 Every 3 to 4 days, the wall of your stomach is completely renewed.
12:53 This is how your body avoids digesting itself.
12:56 When a person stretches, the temperature around their nose and in the inner corners of their eyes increases.
13:02 This phenomenon is known as the Pinocchio effect.
13:05 Hmm...
13:07 The liver is the only human organ that can regenerate completely.
13:11 Even if it only represents 25% of its initial weight, it can fully regenerate.
13:17 Synesthesia is a rare condition that allows you to taste music or hear colors.
13:22 But only 1 in 2,000 people have it.
13:26 Nowadays, our nails grow faster than half a century ago.
13:30 It may be because we eat more protein than before.
13:34 You start to feel thirsty when your water loss reaches 1% of your body weight.
13:39 Beyond 5%, you can even faint.
13:42 And if you lose the equivalent of 10%, hmm... let's just say it'll end badly.
13:48 Your brain can generate more than 48 thoughts in less than a minute.
13:52 This represents nearly 3,000 thoughts per hour and more than 70,000 per day.
13:57 Each person has about 150,000 hairs on their head.
14:01 On average, each hair grows 1.5 cm per month.
14:05 If we combined the growth of each hair, it would reach 15 km per year.
14:10 If you have a cramp in your leg, pull your big toe towards you.
14:14 This will allow you to stretch your muscles and reduce the spasm.
14:18 We have bacteria that can produce electricity in our intestines.
14:22 These bacteria release electrons, which creates tiny electric currents.
14:27 This could be a way to generate energy and light up lights.
14:31 At the end of your life, an average person can remember up to 150 billion pieces of information.
14:37 If you brush your teeth before eating or drinking, you risk damaging your taste buds.
14:43 Most toothpaste contains two chemical substances,
14:47 sodium lauryl ether sulfate and sodium lauryl sulfate,
14:51 which reduces the ability to taste sweet foods and increases the ability to taste bitter foods.
14:57 The mutation of the gene DEC2 allows some people to sleep only a few hours a night to feel in good shape.
15:06 On average, these people wake up at 4 or 5 in the morning.
15:10 Less than 5% of the world population has this characteristic.
15:14 Only humans produce tears related to emotions.
15:18 Animals cry to lubricate their eyes.
15:21 Women have more taste buds than men.
15:25 This is one of the reasons why 35% of women are super-tasters,
15:29 that is, people who taste more than others.
15:32 Only 15% of men have this ability.
15:36 It is difficult to recognize a person you already know if, on a photo, this person has no eyebrows.
15:42 This proves that eyebrows are more important than eyes in recognizing faces.
15:48 When they cross their hands, 50% of people put their right thumb over their left thumb.
15:54 49% of people do the opposite, and 1% put their thumb in front of each other.
16:00 Your brain contains more than 86 billion nerve cells,
16:04 connected to each other by 100 billion connections.
16:07 That's a lot more than the number of stars in the Milky Way.
16:10 And if you wanted to count all these cells, it would take you 3,000 years.
16:14 What a great waste of time!
16:17 The memory capacity of your brain is equivalent to 4 Teraoctets on a hard drive.
16:22 That's more than 8 million photos.
16:26 You are likely to remember up to 10,000 different faces.
16:30 This number varies from person to person, but the average is 5,000.
16:34 This does not mean that you can put a name on each face.
16:37 It's just about recognizing the features.
16:41 If you walked in the same direction for 12 hours a day,
16:44 it would take you about 800 days to go around the globe.
16:49 Bajos are a group of nomads that live in the waters around the Philippines, Indonesia and Malaysia.
16:55 Thanks to a rare genetic mutation, they can stay underwater for up to 13 minutes.
17:00 They can also dive up to 60 meters deep.
17:04 Eating rockfort can influence your dreams by making them more lively.
17:09 If your ears hurt when you're on a plane,
17:12 you can solve this problem by simply chewing a chewing gum.
17:16 This allows you to open your ear canal, a small passage that connects your throat to your middle ear,
17:21 and equalize the pressure in your ears.
17:23 You can also swim to open your ear canal.
17:27 Oceans cover more than 70% of the Earth's surface.
17:31 On average, the ocean has a depth of 8 Empire State Buildings,
17:35 and less than 5% of these mysterious depths have been explored.
17:39 It is even possible to find lakes and rivers under the ocean.
17:42 They are denser than the rest of the water around them, so you can clearly see the difference.
17:47 When coral is in shallow waters,
17:50 the intense sunlight can damage the algae that live inside.
17:54 To protect the algae, the coral produces certain proteins that act as a kind of solar screen.
17:59 Most of the ocean may not have been explored,
18:02 but what we know is that about 20 million tons of gold are scattered in these dark waters.
18:07 It is scattered in very small quantities, which is why it is not profitable to exploit it.
18:12 If we could extract it, each person on the planet would receive 4 kilos of gold.
18:17 When sharks need their morning coffee, they also go to Starbucks.
18:21 In 2002, researchers discovered an area in the Pacific Ocean called the White Shark Café,
18:26 where the great white sharks come during the winter.
18:29 They meet, tell jokes and laugh at the number of humans they have frightened,
18:34 and then return to the coast to scare us again when the weather warms up.
18:38 Have you ever tasted a great white coffee latte?
18:41 The widest point in the Pacific Ocean goes from Indonesia to Colombia,
18:45 and at this place it is 20,000 km wide,
18:48 which is more than five times the diameter of the Moon.
18:51 One could imagine that the oceans are cold,
18:54 especially in the depths where the temperature is only 4.4 degrees.
18:57 But there is an exception.
18:59 It comes out of the hydrothermal vents at the bottom of the sea at a temperature of 400 degrees.
19:04 Humans are the only animals whose brains shrink with age.
19:08 They can even do it because of isolation and loneliness.
19:12 Other animals, even some of our distant cousins from another branch of the genealogical tree,
19:17 like monkeys and chimpanzees, do not have this problem.
19:20 Would television be responsible?
19:22 Our tympans have nothing to do with the meaning of sight,
19:25 but they still move when we move our eyes.
19:28 Over a lifetime, our heart beats on average more than 2.5 billion times.
19:32 Some have counted.
19:34 Our nose can detect more than a billion smells,
19:37 and our lips are hundreds of times more sensitive than the tip of our fingers.
19:41 Two parts of the body never cease to grow, the nose and the ears.
19:45 Capybaras are resilient.
19:47 They can survive in extreme conditions and have been there since the dinosaurs reigned on our planet.
19:52 But the queen of termites is the great champion with a lifespan of 50 years.
19:56 It is the longest life a bug can live.
19:59 Ordinary termites live only one to two years.
20:02 It is not water that the chameleons store in their bones, but fat.
20:06 They store water in their blood.
20:08 Bees can fly very high, at more than 9,000 meters in altitude,
20:11 which is higher than the Everest, the highest peak on our planet.
20:15 The lazy ones are able to hold their breath longer than the dolphins.
20:19 Yes, they slow down their heart rate and can stay like this for nearly 40 minutes.
20:24 Dolphins have to go back to the surface to get some air every 10 minutes.
20:28 The moon has volcanoes, and scientists think they could have been active about 100 million years ago,
20:33 when the dinosaurs still reigned on our planet.
20:36 Wow, the show must have been magnificent!
20:40 There are watermelons the size of a grapefruit.
20:43 Watermelons look like very small watermelons, but they taste like citrus.
20:49 The kangaroo mouse doesn't feel the need to drink water.
20:52 It lives in the Nevada desert, and as its habitat is very dry,
20:56 it has simply learned to quench its thirst with the seeds it eats.
21:00 You may think that parking is expensive in the neighborhood where you live,
21:04 but it is probably cheaper than a parking lot in Hong Kong.
21:07 A simple 13 square meters square in front of The Center,
21:10 which is the fifth tallest building in the city, was bought for nearly a million dollars.
21:15 That's a lot of bus tickets!
21:17 Speaking of expensive things...
21:19 The world's most expensive hot dog costs $169, and you can taste it in Seattle.
21:25 An Australian barista set a world record for the largest number of cappuccinos made in an hour.
21:31 420!
21:32 You can taste the garlic with your feet, rub a crust directly on your feet,
21:36 don't forget to take off your socks beforehand, and wait.
21:39 The chemical compound responsible for its unique smell can be absorbed by the skin,
21:43 even if the crust is not in your mouth.
21:45 In fact, the Omars can do the same experiment.
21:48 They can taste any food with their feet.
21:52 Researchers have found many traces of prehistoric animals, or of our human ancestors,
21:57 who lived thousands of years ago.
21:59 Bones, teeth, stone tools, and a piece of chewing gum dating back almost 10,000 years.
22:05 In Tibet, there are black diamond apples, which are neither green nor red, but dark purple.
22:11 The place where they grow receives a lot of ultraviolet light during the day,
22:15 and the temperatures drop drastically during the night,
22:18 which makes the skin of the apple take a darker color.
22:21 Australia has a lake of a naturally pinkish-pinkish color.
22:25 This unusual color is due to the pigment of a certain type of algae that lives there.
22:29 When sweat comes out of the pores of your body, bacteria decompose it into acid.
22:34 What most deodorants do is get rid of bacteria on your skin.
22:38 People used to dream a lot more in black and white than they do today.
22:42 It's because they watched television in black and white.
22:44 Blue cheese can influence your dreams and make them more alive.
22:48 As for the shell 2, it could be used to grow new human bones.
22:53 Chicken shell 2 contains calcium carbonate, an element also contained in our bones.
22:59 The food in the plane will probably taste different from the same food on the ground.
23:04 It's because you lose up to 30% of the sensitivity of your taste buds
23:08 because of the dryness and pressure in the cabin.
23:12 This is particularly true for salty and sweet foods.
23:15 Your nostrils don't work with the same efficiency all the time.
23:19 When you breathe, a single nostril does most of the work, and it's relayed every two hours.
23:25 You can't taste food without saliva.
23:28 Your taste buds have chemoreceptors that recognize different flavors.
23:32 But they need a liquid for these flavors to bind to their molecules.
23:36 So you can't taste things that saliva doesn't dissolve.
23:40 The brain can't really feel pain.
23:43 It does have a pain center, but it doesn't have a pain receptor.
23:47 When your head hurts, you can feel it because of nerves, tissues and blood vessels around your brain.
23:53 A single human hair can support a weight of 100 grams, or the weight of two chocolate bars.
23:58 The nails and toes grow almost four times slower than the nails and hands,
24:02 which are more exposed and used more frequently.
24:05 There must be at least a few photos where you have red eyes.
24:08 When the camera flashes, your eyes aren't prepared for such a high light.
24:13 Your pupils are dilated, which is why the light is reflected on the red blood vessels of the coroids.
24:19 It's a layer of tissue at the back of your eye that feeds your retina.
24:23 Your right lung is bigger than the left one because your body needs to make room for the heart.
24:29 Your teeth are the only part of your body that can't heal on its own.
24:33 The masseter is the most powerful muscle you have, compared to its weight.
24:37 With the rest of the muscles in the jaw, it can close your teeth with a force of 90 kilos on the molar
24:43 and 25 kilos at the incisors.
24:46 Onions produce a special chemical irritant that stimulates special glands in your eyes,
24:51 which causes them to release tears.
24:53 Your nose can memorize up to 50,000 smells.
24:56 Your nose can memorize up to 50,000 different smells and detect more than 1,000 billion smells.
25:01 We all have a unique smell, except for real twins.
25:05 This smell is partly determined by genetics, but it also depends on your diet, your hygiene and the environment.
25:12 Eating snow is not the best way to stay hydrated.
25:15 Your body needs too much energy to turn it into water.
25:18 Snow can give you a little hydration, but it will also lower your body temperature,
25:24 which is not the best scenario if you try to survive in difficult winter conditions.
25:29 You burn between 100 and 200 calories per hour while standing.
25:33 Sitting burns 60 to 130 calories depending on your size, weight, sex and age.
25:39 Brain freeze is a headache caused by ice.
25:43 This is how your brain tells you to slow down and maybe stop eating something very cold.
25:49 The main purpose of the eyelashes is to protect your eyes from the sand, humidity, dust and debris in the air.
25:56 Your eyelashes detect when something is too close to your eyes,
26:00 like an insect flying at you and triggering a blinking reflex.
26:04 Blinking also helps you when you have to evacuate tiny particles or debris stuck in your eyelashes.
26:10 These are small openings you have in your eyelids. This is where tears are created.
26:15 As for your eyebrows, they prevent sweat from flowing directly into your eyes.
26:19 Your skin at this point and the shape of your bones also work together to direct the sweat to the sides of your face.
26:26 We are not the fastest, strongest or greatest of the animal kingdom,
26:30 but we are the best at running long distances.
26:33 It is because we have long legs that our body can lose excess heat by sweating.
26:38 A long time ago, our ancestors hunted animals by chasing them for long periods.
26:44 This ended up exhausting the little creatures.
26:47 The five basic senses are taste, touch, sight, sound and smell, but people have more sense than that.
26:54 Proprioception is the fact of being aware of the parts of your body and their position, even if you do not see them.
27:00 For example, if your arm is behind your back, you know it's there.
27:04 If you were a pigeon, you wouldn't know it,
27:06 because these creatures don't know that their tentacles exist if they don't see them.
27:11 Thermoception is the ability to perceive temperature.
27:15 Equilibrioception is the sense of balance.
27:18 There is also nociception, which allows you to feel pain,
27:21 and chronoception, which is the way you can feel the time passing.
27:25 There is even more sense in the animal kingdom.
27:28 Electroreception and magnetoreception, but humans don't have them.
27:32 You can't see your taste buds.
27:34 These little bumps on the tongue are lingual buds.
27:37 There are four kinds of them.
27:39 Circumvalate, foliate, fongiform, filiform.
27:43 They are all covered with taste buds, except the last one, filiform.
27:47 Filiform buds seen through a microscope.
27:49 It is responsible for the sense of touch of your tongue.
27:52 Your ear is responsible for 50% of the total strength you have in your hand.
27:57 Your liver is a very important organ that works a lot and is responsible for 500 individual functions.
28:02 Up to 10% of its content is composed of fat.
28:05 The liver can regenerate.
28:07 You can burn calories when you take a hot bath,
28:10 as much as if you were taking a half-hour walk.
28:13 People usually need 7 minutes to fall asleep.
28:16 This time is shorter if you just ate a meal with a spoon.
28:19 On average, your heart is as big as your fist.
28:22 It beats 115,000 times and pumps about 7,600 liters of blood per day.
28:27 Even twins don't have the same tongue.
28:30 The tongue is made up of a set of mobile and powerful muscles that never get tired.
28:35 It contains between 5,000 and 10,000 taste buds.
28:39 These little white and pink bumps on your tongue are not taste buds,
28:43 but each of them has several inside its superficial tissue.
28:48 Evolution gave us taste buds so that we could stay alive.
28:52 For example, bitter and sour flavors can indicate that you are eating rotten food or toxic plants.
28:59 The back of the tongue is more sensitive to bitter flavors,
29:02 which explains why we can spit out bad food before swallowing it.
29:06 Salty and sweet flavors allow us to know if the food is rich in nutrients.
29:10 By the age of 60, most people lose half of their taste buds.
29:15 Indeed, your tongue is pretty cool, and these fingerprints can be used for biometric authentication,
29:21 just like digital fingerprints.
29:23 Each of us has a different and unique tongue print,
29:26 so if you don't want to reveal your secret identity, you just have to hide your tongue.
29:30 It's funny, isn't it?
29:31 Why do we have digital fingerprints?
29:33 Scientists had many different theories on the subject,
29:36 but they now believe that it's because digital fingerprints make it easier for the skin to stretch.
29:41 They allow us to avoid bulbs, protect the skin from injuries, and improve our sense of touch.
29:48 Humans are not the only ones with unique digital fingerprints.
29:51 Koalas too.
29:53 Only about 7% of people are left-handed.
29:56 Left-handed people chew most of the time the food on the left side of their mouths,
29:59 while right-handed people do it on the right side.
30:02 We lose about 5 kg of skin cells each year.
30:05 But don't worry, we replace them quickly.
30:08 We produce 15 seconds more cells than there are people living in the United States.
30:12 Our body regenerates constantly, and we replace our skin hundreds of times throughout our lives.
30:17 Yes, the whole body regenerates, except for the teeth.
30:20 It's the only part of the body that can't do it.
30:23 Our teeth are similar to that of a shark.
30:25 Their teeth also have a substance called dentin inside, and they are as solid as ours.
30:30 Of course, theirs are more pointed and bigger, but still.
30:33 Teeth are part of the human skeleton, even if they are not considered bones.
30:38 You spend about 38 days of your life brushing your teeth.
30:41 And guess what? You might brush them too much.
30:44 Indeed, they can become more sensitive because they use natural enamel.
30:48 Your left and right lungs are not the same size.
30:51 The right is bigger because the left shares its space with the heart.
30:55 Hockey is a symptom that almost all mammals know from time to time, and not just humans.
31:00 The record was set by a man named Charles Osborne.
31:03 He couldn't stop playing hockey for 68 years.
31:06 It seems like no one ever told him about the thing that consists of eating sugar.
31:10 There is only one part of your body that doesn't receive a regular blood supply, and that's your nose.
31:16 It receives oxygen directly from the air.
31:18 Our eyes can differentiate 10 million different colors.
31:21 The muscles that help our eyes focus on something make about 100,000 movements a day.
31:26 If you wanted your legs to do the same work, you would have to walk a long way, at least 80 km.
31:33 We can't all see infrared light or ultraviolet rays.
31:36 Only 1% of us can.
31:39 And if you can see one of those rays, it doesn't necessarily mean you can see the other.
31:43 Research shows that everyone with blue eyes in the world could be related, or at least share a very distant ancestor.
31:50 Scientists examined individuals with blue eyes from Turkey, India, Jordan and Scandinavia.
31:56 They all had the same genetic sequence of the color of their eyes.
32:00 They think this characteristic comes from a person with blue eyes whose genes mutated about 10,000 years ago.
32:05 Before that, the eyes were all just different shades of brown.
32:09 People with blue eyes are generally a little more sensitive to pain than other individuals.
32:14 We blink about 20 times a minute, which means we do it more than 10 million times a year.
32:20 The fact that we look like sharks also affects our eyes.
32:24 If a part of your eye is damaged, you can replace it with a shark's.
32:27 It's convenient, isn't it?
32:29 We can't stay awake with our eyes open.
32:31 Try it!
32:32 It's very difficult to ignore your natural reflexes.
32:35 Eels also have their own life, since only one eel lives about 150 days before it dies.
32:40 We all have a skin rash when we hear good news, our favorite song, or when it's ridiculously cold in the freezer.
32:47 It's a reflex that comes from our ancestors.
32:49 It happens when we release adrenaline.
32:52 It makes our hair stand on end and helps us look more imposing.
32:56 Aaaaaah!
32:57 Scary, isn't it?
32:59 The human brain has 100 billion neurons and a memory capacity of more than 4 teraoctets, which is huge.
33:06 Your brain uses more than a quarter of the oxygen your lungs absorb, and it's mainly composed of water,
33:11 more than 75%.
33:13 It's still very hydrated.
33:16 It's not true that humans only use 10% of their brain.
33:19 We use much more than that, even during our sleep.
33:22 Most of our brain is constantly active, but we don't require all parts at the same time.
33:28 Of all species, humans are the only ones that can rust.
33:31 This phenomenon is due to an adrenaline rush.
33:33 When you feel your face turn red, know that your stomach is red too.
33:37 It's weird.
33:38 When you crack your joints, the sound you hear is that of tiny gas bubbles that are released.
33:44 There are gas pockets trapped between your joints, so when you stretch them, they make a dry noise.
33:49 Oh, how nice it is!
33:51 Ah!
33:52 If you watch a very touching movie in space and start crying, your tears won't flow.
33:59 They will accumulate around your eyeballs.
34:03 Your eyes will become too dry, and you'll feel like they're burning.
34:06 All the liquid on your body will evaporate, including the surface of your tongue.
34:11 Speaking of burning, it's something that fire can't do in space.
34:15 Indeed, fire can spread when there's a flow of oxygen.
34:19 And since there isn't any in space...
34:21 Once they've exploded, stars aren't supposed to come back to life.
34:26 But some stars have somehow survived a huge supernova explosion.
34:31 These zombie stars are rather rare.
34:34 Scientists have found a very large one, called LP40365.
34:39 It's a partially burned white dwarf.
34:42 A white dwarf is a star that has burned all of its hydrogen,
34:46 and this hydrogen was previously its nuclear fuel.
34:49 In this case, the final explosion was perhaps weaker than it usually is.
34:54 Not powerful enough to destroy the star as a whole.
34:58 It's as if a star wanted to explode but didn't succeed,
35:02 which explains why some of the matter survived.
35:05 If you ever go into space, don't take off your suit,
35:08 except if you're in a spaceship.
35:10 In space, the air in your lungs will spread, as will the oxygen in the rest of your body.
35:15 You'll be like a balloon, twice as big as your normal size.
35:19 Good news, the skin is elastic enough to contain you,
35:22 which means you won't explode.
35:25 A little consolation.
35:27 When an object enters a black hole, it changes shape and stretches like spaghetti.
35:32 This happens because gravitational force attracts an object in one direction,
35:37 while compressing it in another.
35:40 A kind of paradox of the legs.
35:43 In addition, a black hole as big as an atom has the mass of a very large mountain.
35:49 There are some in the centre of the Milky Way, called Sagittarius A.
35:54 It has a mass equivalent to one billion suns, but fortunately it's very far from us.
36:00 If you made a big boom on an asteroid, you wouldn't be able to hear its noise.
36:06 Yes, we often hear the sound of spaceships and space battles in movies, but it's just a myth.
36:13 The sound is a wave that spreads due to the vibrations of the molecules.
36:18 A person hits a few metres away from you.
36:21 The sound wave pushes the first air molecule next to the explosion,
36:25 then the second, the third, and so on until the wave reaches your ear.
36:30 To spread the sound, we need molecules like air or water.
36:34 In the atmosphere, sound waves spread very well, but space is empty.
36:39 So there's nothing to hear.
36:41 You can hit your hands, but there won't be any molecules able to vibrate and carry the sound.
36:47 So, to have a conversation, you need a radio or a very good reading of the lips.
36:54 Meteoroids are orbiting the Sun,
36:57 while most of the debris of human origin is orbiting our planet.
37:01 For example, we have launched nearly 9,000 spacecraft in the world, from satellites to rockets.
37:08 Even the smallest pieces can damage a spacecraft at such high speeds.
37:13 Galaxies, planets, comets, asteroids, stars,
37:17 space bodies are things we can actually see in space,
37:20 but they represent less than 5% of the total universe.
37:24 Black matter, one of the greatest mysteries of space,
37:27 is the name we use to designate all the mass of the universe that is still invisible to us.
37:32 And there's a lot of it. It could even make up 25% of the universe.
37:37 Dark energy makes up the remaining 70% of the universe.
37:41 That's 100%, right?
37:44 Now, let's look at the Moon.
37:46 It always looks at us from one side.
37:49 This means that the Moon has a dark side and that the sun's rays never reach it.
37:54 It's a myth.
37:55 The fact is that the Moon is connected to the Earth by gravity.
37:59 There are days and nights there too.
38:02 It's just that its rotation is perfectly aligned with that of the Earth.
38:06 So, when you look at the Moon, you only see one side.
38:10 Although there are also days when the sun shines there,
38:13 it's not the hidden side, it's the distant side.
38:16 We even have pictures of this place.
38:19 And there is one of the largest craters in the entire solar system,
38:22 the South Hight Ken pool.
38:25 It's as wide as two states in Texas.
38:28 Yee-haw!
38:30 A myth that also turned out to be false,
38:32 insinuating that no one would ever go to the Moon.
38:36 This is the original space suit of the first astronauts who went there.
38:40 Look at the sole of the shoe.
38:42 Some people claim that it is impossible that they could leave footprints like this.
38:46 In fact, it's possible.
38:47 On the Moon, astronauts wore extra boots over their suit,
38:51 and their soles perfectly matched the footprints on the Moon.
38:55 The astronauts didn't need them when they left the Moon,
38:58 and threw them away when the lunar walk was over.
39:01 They also left a lot of things there.
39:03 They even threw the seats of the lunar module to reduce its weight.
39:07 By counting all the Apollo lunar missions,
39:10 the total weight of the waste on the Moon rises to about 187 tons,
39:15 including several lunar rovers, debris from space ships,
39:19 six lunar modules and all the experiments left behind.
39:23 It's like three Boeing 737s.
39:26 Another myth about the sun is that it is yellow.
39:29 We're going to send you into space for this one.
39:31 You look out the window and it's white.
39:34 The sun seems yellow to us only through the filter of our atmosphere.
39:38 The composition of the air and its thickness just distort the light of the star.
39:43 But the stars still have different colors.
39:45 The colder stars have bright orange and red colors.
39:49 They are generally very old stars, older than our sun.
39:52 But the young and very hot stars are bright blue.
39:55 The sun is located roughly in the middle of this spectrum.
39:59 Let's move on to another myth about asteroids.
40:02 We have to fly a little further than the orbit of Mars.
40:05 Wow, here we are in an asteroid belt.
40:07 And we constantly have to avoid giant rocks and ice blocks.
40:11 We found ourselves in the middle of a dense cloud and concentrated in asteroids.
40:15 No, not really.
40:16 The fact is that space is huge and the distances are incredible.
40:20 All the rocks and debris from the asteroid belt
40:23 only represent 4% of the weight of the Moon.
40:26 So there really isn't that much over there.
40:29 To understand the dimension of the void in space,
40:32 look at the collision of two galaxies.
40:35 There are billions of stars in each of them.
40:37 If we mix them, it is unlikely that there will be collisions.
40:41 Even here.
40:43 Our brain can only store 7 octets in its short-term memory.
40:47 Don't even try to compare your brain with the capacity of a mobile phone,
40:52 or even the one you had in 2005.
40:54 That's why you have such a hard time learning a phone number by heart.
40:59 Our short-term memory works like a blackboard.
41:03 You can get information, but sooner or later you will miss space.
41:07 To know the capacity of your living memory, do this test.
41:11 Ask a friend to write a list of 10 words and read it to you.
41:15 Most people remember 7 words or less in the list.
41:19 RAM, or living memory, is an essential thing we need
41:24 to do almost all our daily activities,
41:27 including basic conversations, browsing the Internet,
41:30 and even petting your dog.
41:32 Our strongest and most emotional memories are often wrong.
41:37 Our central memory gives us the confidence to believe we remember everything,
41:41 even if most of the details are invented in our head.
41:45 Not only does your brain age, but you age spectacularly too.
41:50 Your bones become more fragile, and your spine is compressed.
41:54 The opposite happens when you rest at night,
41:57 because your bones relax.
41:59 So you wake up a little bigger in the morning than in the evening.
42:03 In mammals, only humans can walk on two legs all their lives.
42:07 You might think kangaroos and gorillas move in the same way,
42:11 but kangaroos use their tails as third legs,
42:14 and gorillas use their long arms to keep their balance.
42:18 Your bones also contribute to metabolism.
42:21 As they are mainly made of calcium,
42:23 when there is not enough of this element in the blood,
42:26 the bones begin to reject it in the blood, which balances the body.
42:30 The same reaction also works in the opposite direction.
42:33 When there is too much calcium in your blood,
42:36 it is sent to the bones to be stored there later.
42:39 The only bone in your body that has the humorous blood is the inside of your arm.
42:44 That's why the bone that is there is called the humerus.
42:47 No, that's totally wrong.
42:49 Let's move on to the following facts.
42:51 The only bones that never grow up are in our ears.
42:54 We can hear thanks to these little bones,
42:56 because they have adapted to transmit sound vibrations.
43:00 Doctors call them the ossicular chain.
43:03 One of these auditory bones, the calf, is the smallest bone in your body.
43:08 It is not larger than a grain of rice.
43:10 Our size, the shape of our body and the color of our skin
43:14 depend a lot on where our ancestors lived,
43:17 but we can adapt to new conditions, even during our own life.
43:21 For example, if you move from the plain to the mountains,
43:24 you will end up developing more red blood cells to compensate for the lack of oxygen.
43:29 And naturally, if you go from a colder climate to a warmer and more sunny climate,
43:34 your skin will become darker to adapt.
43:37 Our lifespan is programmed in our cells.
43:40 They renew and divide constantly,
43:42 but they are a kind of internal clock that stops at some point.
43:46 Some cells also stop reproducing earlier than others.
43:50 On average, cells stop dividing when we reach the age of 100.
43:55 This means that if we found a way to deceive our cells
43:58 so that they stop the mutiny, we could potentially live forever.
44:03 Body fat is not just an aesthetic nuisance.
44:06 It acts as an insulating material, energy reserve and shock absorber.
44:11 It is your body that sends the most fat into the region of your waist,
44:14 because that is where your internal organs are.
44:17 If something happens, this layer of fat could protect your vital organs from irreparable damage.
44:23 Be careful, your skull is not made of one bone.
44:26 It is actually made up of 28 different bones,
44:29 many of which have merged to protect your brain.
44:32 The jawbone, or lower jaw, is the only bone in the skull that is not attached to the surrounding bone.
44:38 It is attached by subjunctive tissues and muscles.
44:41 This makes it so mobile.
44:43 You can move it in the direction you want.
44:45 You can actually chew with your jawbone.
44:48 Another word for "maché".
44:51 The strongest muscles of your body are not located at the level of your arms or legs.
44:55 They are in your head.
44:57 The masseter is the main muscle responsible for chewing.
45:01 It must be the strongest so that you can eat normally.
45:05 Do you know these muscles that allow you to move your ears?
45:08 They are the temporalis, located above your temples.
45:11 They also help you chew your food.
45:14 We have two very fast muscles, which control the closure of the eyelids.
45:19 They are also the fastest muscles of our body.
45:22 Our eyes are fragile and need protection.
45:25 So the reflex that protects them must be as fast as the lightning.
45:28 These muscles can close the eyelids in less than a tenth of a second.
45:32 People with double-jointed thumbs can bend them backwards.
45:37 It seems very unusual and very few people can do it.
45:41 Yet it's quite commonplace.
45:43 Even if it looks painful, it doesn't hurt at all for someone with a double-jointed thumb.
45:48 We only recognize blue, yellow and red-green colors.
45:54 Everything else is a combination of these three colors.
45:57 It's impossible to calculate how many of these combinations the human eye perceives.
46:01 Because each person has slightly different vision.
46:04 But we are around one million combinations on average.
46:07 Do you see the top?