Des faits quotidiens qui vous feront remettre en question tout ce que vous savez

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Transcript

00:00:00Why do we think so commonly that dogs are Daltonian?

00:00:04They really see the colors, even if their spectrum is more limited than ours.

00:00:08They distinguish quite well blue, yellow and purple.

00:00:12But it would be difficult to make the difference between orange, red and green.

00:00:16So if you want to redecorate your dog's house, you should maybe use purple and blue colors.

00:00:22Animals, plants and humans, we are all linked and have common traits.

00:00:27Because we all evolved from the same micro-ancestor.

00:00:31This is the original ancestor of our planet, Luca.

00:00:35This organism, 3.8 billion years old, is our last universal common ancestor.

00:00:42Closing your eyes can improve your memory.

00:00:45Let's say you want to listen to a story and see how much you can remember.

00:00:49Studies have shown that if you close your eyes and rest for 15 minutes, you will remember better.

00:00:55It's a good technique when you study or try to remember a painful piece of information.

00:01:00The pink corner of your eye is actually the vestige of the third eyelid.

00:01:05We all have this mysterious membrane.

00:01:07The third eyelid is much more important in some mammals and birds because it protects their eyes from dust.

00:01:13But for humans, this tissue has no particular function.

00:01:16And scientists think that we will end up losing it.

00:01:21When potatoes are exposed to too much light, they usually turn green,

00:01:25whether they are in a factory, a warehouse or a field.

00:01:28This happens because they begin to form chlorophyll, a pigment that gives plants their green color.

00:01:34So when you see green chips, it means they were made from a potato that has been exposed to light for a long time.

00:01:42But it's not because there are some in your package that you should eat them.

00:01:46It turns out that the green areas on potatoes and chips are not good for you.

00:01:51Nothing will happen if you eat one or two.

00:01:54But if you eat too much, you may feel a certain discomfort.

00:02:00Despite their name, some oranges are not orange.

00:02:04Some initially contain large amounts of chlorophyll, which gives this citrus its green color.

00:02:11As it ripens, the chlorophyll slowly disappears when the fruit is exposed to cool temperatures.

00:02:17It is at this moment that it takes its orange color.

00:02:20But this is also the reason why, in the hot regions of the world, oranges remain green.

00:02:26If you ordered something small on Amazon, like a pen, a simple book or something else,

00:02:31you may have received it in a box that seemed too big for your article.

00:02:35And it's not an accident or a coincidence.

00:02:38It comes from their complex expedition algorithm.

00:02:41It takes into account the size of the other packages intended for the same place,

00:02:44as well as the size of the expedition vehicle.

00:02:47The small article receives a box whose size corresponds to the space available inside the vehicle

00:02:52with the other packages and prevents the boxes from sliding.

00:02:57The physicist and inventor Percy Spencer discovered microwaves by accident.

00:03:02He was building a magnetron for some of his radar equipment.

00:03:06At some point, he realized that the chocolate bar he kept in his pocket had started to melt.

00:03:12Out of curiosity, he directed the microwaves towards eggs that exploded and popcorn that burst.

00:03:19This is how he discovered a formidable tool for heating food,

00:03:23which uses less energy than a classic oven.

00:03:27In its original version, the paste substance we now call Play-Doh

00:03:32was a cleaning product for wallpaper.

00:03:34It was invented and sold to remove dust from wallpaper.

00:03:38At the time it appeared on the market, it was only found in a broken white color.

00:03:43But later, when they started selling it as a toy,

00:03:46this substance was produced in yellow, blue and red.

00:03:49Today, it exists in more than 50 different colors.

00:03:53Play-Doh had a slightly different purpose at first.

00:03:56It was supposed to be wallpaper.

00:03:58In the 1950s, when it appeared,

00:04:02two engineers decided to glue two shower curtains together.

00:04:05This is how they trapped small air bubbles between them.

00:04:08They tried to create a kind of wallpaper with a texture, but it didn't work.

00:04:13A few years later, IBM had to ship data processors

00:04:16and needed something to protect them.

00:04:19That's when the bubble paper phenomenon appeared.

00:04:21A study showed that a single minute spent making bubble paper burst

00:04:25is as soothing as a 30-minute massage.

00:04:28Why don't electric fans cool the air?

00:04:31All you have to do is place a thermometer in front of the device

00:04:34and choose turbo mode so that the temperature doesn't drop.

00:04:37In fact, the temperature could even increase

00:04:40if you leave the thermometer next to the fan thanks to the electric current.

00:04:44A fan doesn't cool the air,

00:04:46but it cools you or any other object containing water.

00:04:50An electric fan improves air circulation in a closed space

00:04:54and accelerates evaporation, which cools liquids,

00:04:57including your skin sweat.

00:05:01Did you notice that the cap of the pens has little holes at the top?

00:05:04It seems strange at first, but it's to save your life.

00:05:08If you accidentally swallow this cap,

00:05:10the hole allows you to continue breathing

00:05:13because the cap doesn't completely block the airways.

00:05:17If you look closely at the night sky,

00:05:20you'll see that the stars have different shapes and sizes.

00:05:23White is the most common color, it's true,

00:05:26but it's also felt in shades of red, blue and yellow.

00:05:29But you'll never see green stars.

00:05:31It's not that stars don't emit green light,

00:05:34it's just that our eyes don't see it that way.

00:05:36Stars have different colors when they burn at different temperatures.

00:05:40The hottest stars are blue,

00:05:42while the coldest stars seem to burn in red.

00:05:45But they all shine in different colors.

00:05:47They emit different wavelengths,

00:05:50which represent various parts of the spectrum of colors.

00:05:53We can't see all these wavelengths separately.

00:05:56We only see the main light wavelength,

00:05:59which is the predominant color.

00:06:01Thus, medium-temperature stars emit green photons in most cases,

00:06:05but they don't seem green to us.

00:06:07When we try to treat an object that generates many red,

00:06:10green, blue and yellow photons at the same time,

00:06:12our eyes see it as white.

00:06:14This is the same reason why medium-temperature stars,

00:06:17like our sun, appear white to us.

00:06:22Why do we blink our eyes?

00:06:24Well, to moisten and clean the eye.

00:06:26Every time you close your eyes,

00:06:28the lacrimal glands secrete a salty substance

00:06:31that sweeps the surface of your eye.

00:06:33It then evacuates all these tiny particles of dust

00:06:36and also lubricates the exposed parts of your eyeball.

00:06:40We usually blink our eyes every 4 to 6 seconds,

00:06:43except if the eyes are more irritated.

00:06:45In this case, we blink our eyes more frequently

00:06:47to keep them moist and clean.

00:06:49But that's not all.

00:06:50Blinking our eyes also helps our brain to rest.

00:06:53It must deal with so many things all the time

00:06:55that it's normal to give it a break from time to time.

00:06:58Thus, blinking our eyes

00:07:00helps our brain run about 15 to 20 times per minute.

00:07:03When we close our eyes,

00:07:05we help our brain to relax

00:07:07and take a very short and yet effective mental break.

00:07:10This is why we blink our eyes more

00:07:12when we are in the middle of a task

00:07:14that requires an important mental activity.

00:07:16Why do we have nails?

00:07:18They are generally made up of a specific type of protein

00:07:21that we find in fur, hair, claws and shoes.

00:07:24It's keratin.

00:07:26And unlike claws, nails are flat and wide,

00:07:29which makes them more effective

00:07:31in protecting the tip of the toes and fingers

00:07:33from potential injuries.

00:07:35Not only do nails protect sensitive areas,

00:07:37but they are also a rigid support

00:07:39that allows you to take and separate small objects more easily.

00:07:43How could you take a simple piece of jigsaw

00:07:46or peel off a sticker from its support without nails?

00:07:49It would be almost impossible without additional tools.

00:07:52Great apes and chimpanzees

00:07:54also use their feet for these delicate tasks.

00:07:57Primates probably developed nails

00:07:59because they needed help with simple tasks

00:08:02like firmly grabbing branches or removing ticks.

00:08:05Raspberries, apricots, strawberries and cherries are not berries.

00:08:09To be classified among berries,

00:08:11they must have three layers.

00:08:13An outer protective layer,

00:08:15a fleshy layer in the middle

00:08:17and the inner part where the seeds are.

00:08:19In addition, a plant must come from a flower

00:08:21with a green soil

00:08:23and have two seeds or more.

00:08:25Thus, according to this criterion,

00:08:27apricots and cherries are berries.

00:08:30There are also other plants

00:08:32that we did not expect to find in this category.

00:08:34Kiwis, bananas,

00:08:36watermelon, tomatoes,

00:08:38eggplants and even peppers.

00:08:40You've probably heard that your ears and nose

00:08:43are the parts of the body that never stop growing.

00:08:45This is due to the effects of skin changes

00:08:47and gravity.

00:08:49Other parts of your body change in the same way,

00:08:51but you can't see it as well

00:08:53as you can see what's going on

00:08:55with your nose and your ears.

00:08:57You need a drop of liquid,

00:08:59a high-quality 3D printer

00:09:01and about two hours of work

00:09:03to make a tiny fidget spinner.

00:09:05It will be smaller than a strand of hair.

00:09:07This is what researchers at the Oak Ridge National Laboratory

00:09:09have managed to achieve.

00:09:12In reality,

00:09:14double-cream Oreos are not doubly stuffed.

00:09:16A math teacher weighed

00:09:1810 classic Oreos,

00:09:2010 double-cream Oreos and 10 mega-stuffed Oreos.

00:09:22Double-cream Oreos

00:09:24only weigh 1.86 times

00:09:26as much as classic Oreos.

00:09:29Chipotles are not peppers

00:09:31of a particular variety.

00:09:33They are simply dried jalapeños

00:09:35and smoked.

00:09:38In the form of a gas,

00:09:40the gas has no smell or color.

00:09:42But when it is liquid

00:09:44or solid,

00:09:46it is light blue.

00:09:48The stars caught by black holes

00:09:50are destroyed by their enormous gravity.

00:09:54Pieces of these stars are sucked

00:09:56by the black hole.

00:09:58The rest, in the form of plasma jets,

00:10:00is ejected with such force

00:10:02that it travels light years away.

00:10:06Recently, researchers decided

00:10:08to redraw the genealogical tree

00:10:10of dinosaurs for the first time

00:10:12in 130 years.

00:10:14It seems that two species of dinosaurs

00:10:16should have been grouped

00:10:18from the beginning.

00:10:20These are carnivorous dinosaurs

00:10:22with reptile basins,

00:10:24such as the T-Rex,

00:10:26and vegetarian dinosaurs

00:10:28with bird basins,

00:10:30such as the Stegosaurus.

00:10:32A camel can drink up to 113 liters of water

00:10:34in just over 10 minutes.

00:10:36As for its bone,

00:10:38it is a reserve of fat

00:10:40for periods of food deficiency.

00:10:42Some marine animals,

00:10:44such as salmon and turtles,

00:10:46use terrestrial magnetic fields

00:10:48to locate themselves.

00:10:50Your lungs are not just there

00:10:52to make you breathe.

00:10:54They also produce red blood cells.

00:10:56These are the cells

00:10:58responsible for coagulation.

00:11:00Lungs produce more than 10 million

00:11:02of these small cells per hour.

00:11:04These are the cells

00:11:06that never appear on the periodic table.

00:11:08The J and the Q.

00:11:10If you shoot a bullet at it

00:11:12while you throw it,

00:11:14it will fly.

00:11:16This is the Magnus effect.

00:11:18You can notice this phenomenon

00:11:20in several sports,

00:11:22such as tennis or baseball.

00:11:24Anathedaephobia

00:11:26is the fear that at any time,

00:11:28somewhere in the world,

00:11:30a duck or a gull

00:11:32observes you.

00:11:34The person is not necessarily afraid

00:11:36that the duck or the gull

00:11:38will approach or come into contact

00:11:40with the animal.

00:11:42It is just the fear of being observed.

00:11:44This phobia was first described

00:11:46in a comic book

00:11:48to show that everyone

00:11:50can be afraid of something.

00:11:52Everything can become a phobia.

00:11:54A duck that would constantly observe me

00:11:56would certainly give me chicken meat.

00:11:58Favorite fruit candies are shiny

00:12:00because they are probably covered

00:12:02with carnauba wax.

00:12:04We sometimes use this wax

00:12:06on fruits like apples.

00:12:08It makes candies and fruits shine,

00:12:10but also cars.

00:12:14Peaches and nectarines

00:12:16seem different,

00:12:18but in reality,

00:12:20they are the same fruit.

00:12:22The very soft gene is dominant

00:12:24in peaches,

00:12:26while if it is not,

00:12:28it is not.

00:12:30Crows are good at recognizing

00:12:32people's faces,

00:12:34and they remember it for a long time.

00:12:36It can be a good or a bad thing

00:12:38depending on your behavior with them.

00:12:40It is better not to cross a crow

00:12:42that has one after you.

00:12:44You probably can't tell a crow

00:12:46from another crow,

00:12:48so it's better to say hello to them all.

00:12:52In the city of Yoro,

00:12:54in Central America,

00:12:56thousands of fish fall every year.

00:13:00Residents don't have a choice.

00:13:02Every year, in May or June,

00:13:04a torrential rain

00:13:06crosses the city,

00:13:08leaving fish agonizing in the street.

00:13:12It would seem that the phenomenon

00:13:14is caused by water pipes

00:13:16or tornadoes

00:13:18that would transport the fish.

00:13:20Delivery express in seafood.

00:13:22Oh yeah!

00:13:24It's called a spaghetto.

00:13:28In Italian,

00:13:30the I at the end of the word

00:13:32marks the plural.

00:13:34And the O is a mark of the singular.

00:13:36It's valid for everything.

00:13:38We say gnocco for a single gnocchi,

00:13:40tortellino for a single tortellini,

00:13:42and raviolo for a single bite of this delight.

00:13:46Water can freeze and boil

00:13:48at the same time.

00:13:50It's called the triple point.

00:13:52It's the moment when a substance

00:13:54can be solid, liquid and gaseous

00:13:56at the same time.

00:13:58It's closely related to pressure and temperature.

00:14:02We are used to

00:14:04having a white ranch sauce.

00:14:06But in reality, producers

00:14:08generally add titanium dioxide

00:14:10to make it as white as our sunscreen.

00:14:12Ah! Sunscreen producers

00:14:14also add titanium dioxide to their products.

00:14:16It's also valid for the Caesar sauce

00:14:18and the blue cheese sauce.

00:14:20Our moon had an atmosphere.

00:14:22About 4 billion years ago,

00:14:24volcanic eruptions

00:14:26occurred on our satellite.

00:14:28They released huge volumes of gas,

00:14:30thousands of billions of tons.

00:14:32Too large volumes

00:14:34that didn't have time to escape into space.

00:14:36That's how this atmosphere was formed.

00:14:40Cold water heats up faster than hot water.

00:14:42The speed of this process

00:14:44depends on the temperature difference

00:14:46between the liquid and its environment.

00:14:48That's why cold water

00:14:50needs less time to absorb heat.

00:14:52But that doesn't mean it will boil faster

00:14:54than hot water.

00:14:56Zealandia

00:14:58is a continental block submerged

00:15:00in the Pacific Ocean.

00:15:02It is often described as a fragment

00:15:04or a microcontinent.

00:15:06It measures almost 2 million square meters,

00:15:08which is half of the United States.

00:15:10It was submerged

00:15:12about 23 million years ago.

00:15:14New Zealand is the largest

00:15:16part of Zealandia still on the surface.

00:15:18Human beings

00:15:20are still evolving.

00:15:22Researchers have found several million human anomalies.

00:15:24It turns out

00:15:26that some dangerous genes

00:15:28are slowly being eliminated

00:15:30from DNA.

00:15:32The stars twinkle

00:15:34because of the turbulence

00:15:36in the Earth's atmosphere.

00:15:38It deflects the light from the stars

00:15:40before it reaches your eyes.

00:15:42It gives this sparkling effect.

00:15:46Water goes around the world

00:15:48for a thousand years.

00:15:52This phenomenon is called the thermohaline loop.

00:15:56Bismuth

00:15:58is a white metal

00:16:00with a pink hue.

00:16:02If you melt it and let it cool down

00:16:04very slowly, it forms

00:16:06iridescent cubic crystals.

00:16:08Skittles and M&Ms

00:16:10are colored with

00:16:12coleopters.

00:16:14The red food coloring

00:16:16is made from carmine from skittles.

00:16:18Red lipsticks

00:16:20are also made from skittles.

00:16:24Stones, metals and other minerals

00:16:26that make up the Earth are not distributed

00:16:28homogeneously on the planet.

00:16:32This has several consequences,

00:16:34including the variation of gravity

00:16:36depending on where you are.

00:16:38Altitude also has an effect.

00:16:40When you are at the top of Mount Everest,

00:16:42you weigh slightly less.

00:16:44Don't look down!

00:16:48According to a researcher,

00:16:50there was a substance in the ancient microbes

00:16:52before the evolution of chlorophyll.

00:16:54It is the substance that makes

00:16:56the green plants on Earth.

00:16:58This substance reflected the sun's light

00:17:00in red and purple,

00:17:02which gave a bright purple.

00:17:04If this hypothesis were true,

00:17:06the Earth would have been full of purple animals

00:17:08before the arrival of greenery.

00:17:10Apples have a better taste

00:17:12when they are cut,

00:17:14because they are thus exposed to oxygen.

00:17:16Oxygen activates an enzyme

00:17:18called polyphenoloxidase,

00:17:20responsible for the maturation

00:17:22and browning of the fruit.

00:17:24This phenomenon also occurs

00:17:26when you cut an apple.

00:17:28Oxygen enters through the small cracks

00:17:30caused by the impact

00:17:32and the fruit begins to ripen.

00:17:34Do you like white chocolate?

00:17:36Well, in reality,

00:17:38white chocolate is not enough

00:17:40to make chocolate.

00:17:42It lacks powder

00:17:44or chocolate liqueur.

00:17:46The only product that never perishes,

00:17:48even if it is not stored in the fridge,

00:17:50is honey.

00:17:52It has a low pH and contains a lot of sugar.

00:17:54Bacteria that cause food deterioration

00:17:56do not survive in honey.

00:17:58If two pieces of metal

00:18:00touch each other in space,

00:18:02they unite and fuse.

00:18:04This does not happen on Earth,

00:18:06people will be more honest

00:18:08when they are tired.

00:18:10It is assumed that this is why confessions

00:18:12are usually made late at night.

00:18:14Firefighters extinguish fire

00:18:16with wet water.

00:18:18It is water mixed with wet agents.

00:18:20It is a chemical product

00:18:22that helps water to soak objects

00:18:24and spread more easily.

00:18:28The sun is an average-sized star.

00:18:30However, it is 1,300,000 times

00:18:32the size of the Earth

00:18:34and weighs 333,000 times more.

00:18:40We have been able to dictate

00:18:42our e-mails in Morse since 2004.

00:18:44This date corresponds

00:18:46to the date of codification

00:18:48of the arrow symbol.

00:18:50The arrow is also called comat

00:18:52for commercial A

00:18:54and corresponds to the letters

00:18:56A and C combined.

00:19:00A recent study suggests

00:19:02that the universe is similar to your brain

00:19:04but on a much, much larger scale.

00:19:08The neural network of the brain

00:19:10contains about 86 billion neurons.

00:19:12The observable universe

00:19:14has at least 100 billion galaxies.

00:19:16Galaxies and neurons

00:19:18both have a similar structure.

00:19:20It is a complex network of nodes

00:19:22connected by long filiform fibers.

00:19:24But in each of these systems,

00:19:26the fibers represent

00:19:28only 30% of the total mass

00:19:30and the remaining 70%

00:19:32are either water in the brain

00:19:34or black matter

00:19:36in the universe.

00:19:38The ways in which galaxies

00:19:40and neural networks

00:19:42connect to each other

00:19:44are surprisingly similar.

00:19:46In both cases,

00:19:48the process follows

00:19:50the same physical principles.

00:19:52However, some researchers

00:19:54claim that the resemblance

00:19:56between the brain and the universe

00:19:58leads to a conclusion

00:20:00that has nothing in common

00:20:02with reality,

00:20:04as the brain is a mini-universe.

00:20:06In billions of years,

00:20:08the universe will probably expand

00:20:10so much that we will not be able

00:20:12to see any star in the sky.

00:20:14To transform the Earth

00:20:16into a black hole,

00:20:18it would have to be pressed

00:20:20to the size of a ball.

00:20:22And if we wanted the Sun

00:20:24to become a black hole,

00:20:26it would have to be pressed

00:20:28to the size of a ball.

00:20:30A star-forming galaxy,

00:20:32or starburst galaxy,

00:20:34is a galaxy that forms

00:20:36tons of new stars

00:20:38at lightning speed.

00:20:40This usually happens

00:20:42after the fusion

00:20:44of two galaxies into one.

00:20:46While the Earth

00:20:48has only one natural satellite,

00:20:50Jupiter is surrounded

00:20:52by at least 79 moons.

00:20:54In comparison,

00:20:56our galaxy, the Milky Way,

00:20:58is made up of 250 to 400 billion stars.

00:21:02A supermassive black hole

00:21:04located 250 million light-years away

00:21:06emits the deepest sound

00:21:08ever detected

00:21:10from any object in the universe.

00:21:12It is 1 billion,

00:21:14that is, 1 with 15 zeros,

00:21:16twice as deep as what

00:21:18the human ear can perceive.

00:21:20The planet KELT-9b

00:21:22is located 670 light-years away from Earth.

00:21:24It is an ultra-hot Jupiter,

00:21:26that is, a giant planet

00:21:28at unbearable temperature

00:21:30and with a mass similar

00:21:32to that of Jupiter.

00:21:34On KELT-9b,

00:21:36the heat is so high

00:21:38on the bright side of the planet

00:21:40that it tears up the molecules.

00:21:42Any liquid floating in space

00:21:44turns into a sphere.

00:21:46This also happens

00:21:48in low Earth orbit.

00:21:50KELT-9b has a diameter

00:21:52of more than 105,000 light-years.

00:21:54All the planets of the Solar System

00:21:56could stand between Earth and the Moon

00:21:58with a little space in reserve.

00:22:00Black holes spaghettize objects.

00:22:02This happens when an object

00:22:04exceeds the point of no return.

00:22:06The gravitational force of the black hole

00:22:08then begins to stretch this object

00:22:10in one direction

00:22:12and compress it in another.

00:22:14The first celestial body

00:22:16that astronomers identified

00:22:18is the galaxy Whirlpool.

00:22:20Its long arms are made of gas

00:22:22and stars,

00:22:24and the whole is sprinkled

00:22:26with fine space dust.

00:22:28When you are on Earth,

00:22:30you can only see 5% of the universe.

00:22:32A star that approaches

00:22:34too close to a black hole

00:22:36can be torn by its gravitational force.

00:22:38WASP-12b is a giant planet

00:22:40located 1,400 light-years from Earth.

00:22:42It is mainly composed of gas.

00:22:44Unfortunately,

00:22:46the planet is doomed.

00:22:48It orbits too close to its star.

00:22:50In about 10 million years,

00:22:52WASP-12b will be swallowed

00:22:54by its empty sun.

00:22:56Our galaxy,

00:22:58the Milky Way,

00:23:00and Andromeda,

00:23:02its closest neighbor,

00:23:04will meet in a little less than 4 billion years.

00:23:06When they collide,

00:23:08they will form a huge elliptical galaxy.

00:23:10One of Saturn's smallest moons,

00:23:12Encelade,

00:23:14reflects the sun's light.

00:23:16It makes this moon

00:23:18one of the brightest objects in the solar system.

00:23:20But as it reflects the sun's light

00:23:22instead of absorbing it,

00:23:24the temperatures on Encelade's icy surface

00:23:26drop to less than 200°C.

00:23:28The highest mountain

00:23:30in the solar system is Olympus Mons,

00:23:32on Mars.

00:23:34It is three times higher than Mount Everest.

00:23:36If you were at the top of Olympus Mons,

00:23:38its slopes would be hidden by the curvature of the planet.

00:23:40In our solar system,

00:23:42Mercury and Venus

00:23:44are the only two moonless planets.

00:23:46Scientists who plan to send

00:23:48robots to Mars want to load

00:23:50the machines with a lot of heavy equipment.

00:23:52Robots will also be built

00:23:54with more resistant materials.

00:23:56All this because of the relatively low

00:23:58gravity of the red planet.

00:24:00Everything on Mars

00:24:02is almost three times lighter than on Earth.

00:24:04Pluto's largest moon

00:24:06is half the size

00:24:08of the dwarf planet itself.

00:24:10Charon's fair is the name of this moon,

00:24:12the largest known satellite

00:24:14compared to the size of its mother planet.

00:24:16There are golf balls on the moon.

00:24:18They were launched

00:24:20during the Apollo 14 mission.

00:24:22Mathematicians

00:24:24say that white holes could exist,

00:24:26even if scientists

00:24:28haven't found any yet.

00:24:30If you fell on a white hole,

00:24:32you couldn't get in from the outside,

00:24:34but you would see light and matter

00:24:36escaping from the inside.

00:24:38A complete rotation

00:24:40takes one day,

00:24:42but the Sun is so huge

00:24:44that it needs 25 to 35 Earth days

00:24:46to complete a complete rotation.

00:24:48The moon is not a perfect sphere.

00:24:50It has the shape of an egg

00:24:52because of the Earth's gravity.

00:24:54Space suits

00:24:56protect astronauts

00:24:58from huge temperature differences

00:25:00during spacewalks,

00:25:02from minus 160°C to plus 120°C.

00:25:04A neutron star

00:25:06is born after the collapse of a supernova.

00:25:08After birth,

00:25:10it rotates extremely fast,

00:25:12about 60 times per second.

00:25:14But this rhythm can sometimes reach

00:25:16600 revolutions per second.

00:25:18In 2007, astronomers began

00:25:20to receive ultra-bright

00:25:22and ultra-strong radio signals.

00:25:24Called fast radio surges,

00:25:26they came from a place

00:25:28thousands of light years away.

00:25:30When astronauts are in space,

00:25:32they often see random light flashes.

00:25:34They occur when cosmic rays

00:25:36hit the optic nerve of the eye.

00:25:38If you traveled around

00:25:40Pluto's equator,

00:25:42the distance traveled would be the same

00:25:44as if you were walking from Rome to New York.

00:25:46If you visited GJ 504b,

00:25:48a planet located

00:25:50only 57 light years from Earth,

00:25:52you would see that the planet shines.

00:25:54It is because of the heat

00:25:56that remained after its formation.

00:25:58The color of the planet is a dark red,

00:26:00like a dark cherry blossom.

00:26:02Jupiter has the shortest day

00:26:04of all the planets in the solar system.

00:26:06It lasts only 9 hours and 55 minutes.

00:26:08Because of its fast rotation,

00:26:10Jupiter is not a perfect sphere.

00:26:12It is a little flattened.

00:26:14Venus houses more volcanoes

00:26:16than all the other planets

00:26:18in the solar system.

00:26:20There are at least 1,600

00:26:22on the planet's surface,

00:26:24but most of them are extinguished.

00:26:26Mercury has ridges.

00:26:28When its iron core cools,

00:26:30it contracts.

00:26:32This makes the planet's surface

00:26:34irregular.

00:26:36The nuclear paste

00:26:38found in neutron stars

00:26:40is considered the strongest

00:26:42substance in the universe.

00:26:44These neutron nozzles

00:26:46can be 10 billion times

00:26:48stronger than steel.

00:26:50Some astronomers think

00:26:52that black holes could have

00:26:54no event horizon,

00:26:56alias the point of no return.

00:26:58But the black hole

00:27:00could have trapped things

00:27:02for a while.

00:27:04Later, matter or energy

00:27:06escaped, but in a different form.

00:27:08Each Apollo mission required

00:27:1015 space suits.

00:27:12Each crew member,

00:27:14made up of 3 people,

00:27:16needed 3 suits.

00:27:18One was for training,

00:27:20the other for flight.

00:27:22There was also a life suit

00:27:24in case something went wrong

00:27:26The scientists think

00:27:28Mercury could still have

00:27:30a partially melted core.

00:27:32This could explain

00:27:34why the planet has

00:27:36a magnetic field

00:27:38equal to 1% of the Earth's.

00:27:40The dust storms on Mars

00:27:42are the most violent

00:27:44of all solar systems.

00:27:46They can rage for months.

00:27:48On the planet Kepler-16b,

00:27:50which is 245 light-years away,

00:27:52there are not one,

00:27:54but two suns

00:27:56lying on the horizon.

00:27:58The planet is as massive as Saturn,

00:28:00but has a higher density.

00:28:02It takes 45 minutes

00:28:04to put on a space suit.

00:28:06Once it's done,

00:28:08an astronaut needs

00:28:10an extra hour to adapt

00:28:12to the new conditions.

00:28:14The fireballs that rub the Earth

00:28:16are bright meteors

00:28:18that enter the Earth's atmosphere

00:28:20and then leave it.

00:28:22It's the only big moon

00:28:24of all the known planets.

00:28:26Triton is also getting closer

00:28:28to Neptune.

00:28:30The experts think

00:28:32the moon will disintegrate

00:28:34under Neptune's gravity

00:28:36and form a ring

00:28:38around the gas giant.

00:28:40The dwarf planet Haumea,

00:28:42which is farther away

00:28:44than Neptune,

00:28:46is really weird.

00:28:48It's in orbit

00:28:50around the gas giant.

00:28:52Haumea has two moons,

00:28:54a strangely elongated shape

00:28:56and a day that lasts

00:28:58four terrestrial hours.

00:29:00But the most amazing thing

00:29:02is that the dwarf planet

00:29:04is surrounded by incredibly thin rings.

00:29:06They are probably the result

00:29:08of an old collision.

00:29:10It takes Neptune

00:29:12nearly 165 terrestrial years

00:29:14to complete a complete orbit

00:29:16around the sun.

00:29:18Even twins

00:29:20don't have the same tongue.

00:29:22The tongue is made of a set

00:29:24of powerful, mobile muscles

00:29:26that never get tired.

00:29:28It contains between 5,000

00:29:30and 10,000 taste buds.

00:29:32These little pink and white spots

00:29:34on your tongue

00:29:36are not taste buds,

00:29:38but each of them has several

00:29:40inside its superficial tissue.

00:29:42Evolution gave us taste buds

00:29:44so that we could stay alive.

00:29:46These taste buds can tell you

00:29:48that you are eating rotten food

00:29:50or toxic plants.

00:29:52The back of the tongue

00:29:54is more sensitive to bitter flavors,

00:29:56which explains why

00:29:58we can spit out bad food

00:30:00before swallowing it.

00:30:02Salty and sweet tastes

00:30:04tell us if the food

00:30:06is rich in nutrients.

00:30:08At the age of 60,

00:30:10most people lose

00:30:12half of their taste buds.

00:30:14Each of us has a different

00:30:16and unique tongue imprint.

00:30:18So if you don't want to reveal

00:30:20your secret identity,

00:30:22you just have to hide your tongue.

00:30:24Why do we have digital imprints?

00:30:26Scientists had many different theories

00:30:28on the subject,

00:30:30but today they believe

00:30:32that digital imprints

00:30:34allow the skin to stretch more easily.

00:30:36They allow us to avoid bulbs,

00:30:38protect the skin against injuries

00:30:40and improve our sense of touch.

00:30:42But what about koalas?

00:30:44Only about 7% of people

00:30:46are left-handed.

00:30:48Left-handed people chew

00:30:50most of the time

00:30:52the food on the left side

00:30:54of their mouths,

00:30:56while right-handed people

00:30:58do it on the right side.

00:31:00We lose about 5 kg of skin cells

00:31:02each year.

00:31:04But don't worry,

00:31:06we replace them quickly.

00:31:08We produce 15 seconds more

00:31:10to regenerate our teeth.

00:31:12It's the only part of the body

00:31:14that can't do it.

00:31:16Our teeth are similar

00:31:18to that of a shark.

00:31:20Their teeth also have a substance

00:31:22called dentin inside

00:31:24and they are as solid as ours.

00:31:26Of course, theirs are more pointy

00:31:28and bigger, but still.

00:31:30Teeth are part of the human skeleton

00:31:32even if they are not considered

00:31:34as bones.

00:31:36You spend about 38 days

00:31:38in a natural hospital.

00:31:40Your left and right lungs

00:31:42are not the same size.

00:31:44The right one is bigger

00:31:46because the left one

00:31:48shares its space with the heart.

00:31:50Hockey is a symptom

00:31:52that almost all mammals

00:31:54know from time to time

00:31:56and not only humans.

00:31:58The record was set

00:32:00by a man named Charles Osborne.

00:32:02He couldn't stop hockey

00:32:04for 68 years.

00:32:06This is your nose.

00:32:08It receives oxygen directly from the air.

00:32:10Our eyes can differentiate

00:32:1210 million different colors.

00:32:14The muscles that help our eyes

00:32:16to focus on something

00:32:18do about 100,000 movements per day.

00:32:20If you want your legs' muscles

00:32:22to do the same job,

00:32:24you should walk at least 80 km.

00:32:26We can't all see infrared light

00:32:28or ultraviolet rays.

00:32:30Only 1% of us can.

00:32:32And if you can see one of those rays,

00:32:34you can see the other.

00:32:36Research shows that all people

00:32:38with blue eyes could be related

00:32:40or at least share a distant ancestor.

00:32:42Scientists examined people

00:32:44with blue eyes from Turkey,

00:32:46India, Jordan and Scandinavia.

00:32:48They all had the same

00:32:50genetic sequence of the color of their eyes.

00:32:52They think this characteristic

00:32:54comes from a person with blue eyes

00:32:56whose genes mutated about 10,000 years ago.

00:32:58Before that, the eyes were all

00:33:00different shades of brown.

00:33:02Some people are more sensitive

00:33:04to pain than others.

00:33:06We blink about 20 times per minute,

00:33:08which means we do it

00:33:10more than 10 million times a year.

00:33:12The fact that we look like sharks

00:33:14also affects our eyes.

00:33:16If a part of your eye is damaged,

00:33:18you can replace it with a shark's.

00:33:20It's convenient, isn't it?

00:33:22You can't be naked with your eyes open.

00:33:24Try it! It's very difficult

00:33:26to ignore your natural reflexes.

00:33:28Eels also have their own life

00:33:30cycle.

00:33:32We all have goosebumps

00:33:34when we hear good news,

00:33:36our favorite song,

00:33:38or when it's cold in the freezer.

00:33:40It's a reflex from our ancestors.

00:33:42It happens when we release adrenaline.

00:33:44It makes our hair stand up

00:33:46and makes us look more imposing.

00:33:48It's scary, isn't it?

00:33:50The human brain has 100 billion neurons

00:33:52and a memory capacity

00:33:54of more than 4 teraoctets,

00:33:56which is huge.

00:33:58It uses more than a quarter of the oxygen

00:34:00that your lungs absorb,

00:34:02and it's mainly composed of water,

00:34:04at more than 75%.

00:34:06It's still well hydrated.

00:34:08It's not true that humans

00:34:10only use 10% of their brain.

00:34:12We use much more than that,

00:34:14even during our sleep.

00:34:16Most of our brain is constantly active,

00:34:18but we don't ask for all parts at the same time.

00:34:20Of all species, humans are the only ones

00:34:22able to blush.

00:34:24This phenomenon is due to a boost of adrenaline.

00:34:26When you turn red,

00:34:28your stomach is also red.

00:34:30It's weird.

00:34:32When you crack your joints,

00:34:34the sound you hear is the tiny gas bubbles

00:34:36that are released.

00:34:38There are gas pockets trapped between your joints,

00:34:40so when you stretch them,

00:34:42they make a dry noise.

00:34:44It's so nice!

00:34:46We use 43 muscles when we brush our eyebrows,

00:34:48but only 17 when we smile,

00:34:50although scientists still don't agree on that.

00:34:52Anyway, smile!

00:34:54An average person consumes

00:34:56about 33 tons of food in his lifetime.

00:34:58It's the equivalent of 6 elephants!

00:35:00We breathe about 11,000 liters of air per day,

00:35:02but we can't swallow

00:35:04and breathe at the same time.

00:35:06Most people need about 7 minutes

00:35:08to fall asleep,

00:35:10and we're about the only living beings

00:35:12to sleep on our backs.

00:35:14Randy Gardner decided to set the record

00:35:16for the longest sleepless period.

00:35:18In 1964, he stayed awake for 11 days,

00:35:20or 264 hours.

00:35:22I guess he had noisy neighbors.

00:35:24Of all the animals,

00:35:26humans are the only ones with a chin.

00:35:28When you're thirsty,

00:35:30it means that the water you drink

00:35:32is equal to 1% of your total body weight.

00:35:34If it exceeds 5%,

00:35:36you can even faint.

00:35:38During your life,

00:35:40your body goes from 300 bones to 206.

00:35:42More than half of all your bones

00:35:44are in your feet, ankles, hands and wrists.

00:35:46The largest human bone is the thigh bone,

00:35:48and the smallest is called the calf bone.

00:35:50Your nose can recognize

00:35:52a trillion different smells,

00:35:54and remember 50,000 of them.

00:35:56Women smell better than men,

00:35:58and the sense of smell

00:36:00is 10,000 times more developed

00:36:02than the sense of taste.

00:36:04The surface of our lungs

00:36:06is almost equal to that of a tennis court.

00:36:08So, what is this sensation

00:36:10you feel when you cross a ridge

00:36:12on a Russian mountain

00:36:14and your stomach goes up your throat?

00:36:16Well, the seat belt holds your body in place,

00:36:18but your stomach, your intestines

00:36:20and your small internal organs

00:36:22benefit from a little freedom.

00:36:24It doesn't hurt you,

00:36:26but your nerves can't understand what's going on.

00:36:28They really think your stomach

00:36:30has made a bump in your throat.

00:36:32We are all taller in the morning,

00:36:34because during the day,

00:36:36the cartilage between our bones compresses.

00:36:38This makes us lose about one nail

00:36:40at the end of each day.

00:36:42The nose and ears are parts of the body

00:36:44that never stop growing.

00:36:46The veins and arteries inside your body

00:36:48are long enough to go around the world twice.

00:36:50The blood represents

00:36:52about 8% of your body weight.

00:36:54When you listen to music,

00:36:56the beats of your heart

00:36:58synchronize with the general atmosphere of the song,

00:37:00so choose wisely.

00:37:02Your skin is the largest organ of your body.

00:37:04It accounts for about 15% of your total weight.

00:37:06Know that you can burn more calories

00:37:08by sleeping than by watching TV.

00:37:10Hmm, what if we slept

00:37:12while the TV was still on?

00:37:14Don't panic,

00:37:16but our brain can only store 7 bits

00:37:18in its short-term memory,

00:37:20or even less for some people.

00:37:22Don't try to compare your brain

00:37:24to the capacity of a phone,

00:37:26not even the one you had in 2005.

00:37:28A single octet

00:37:30already corresponds to 8 bits.

00:37:32That's why you sometimes have trouble

00:37:34learning a phone number by heart.

00:37:36Our short-term memory

00:37:38works like a blackboard.

00:37:40You can write information on it,

00:37:42but it takes a lot of space.

00:37:44To check the capacity of your short-term memory,

00:37:46do this test.

00:37:48Ask a friend to write a list of 10 words

00:37:50and read it to you.

00:37:52Most people remember

00:37:54a maximum of 7 elements from the list.

00:37:56Cats don't taste sweet

00:37:58because they don't need it

00:38:00due to their carnivorous diet.

00:38:02They are one of the rare animals on the planet

00:38:04that can't taste sweet things.

00:38:06It's hard to believe,

00:38:08but in this picture

00:38:10you can distinguish a million different colors.

00:38:12When seen in real size,

00:38:14they have a million pixels

00:38:16and each of them is of a different color.

00:38:18Even if you probably

00:38:20can't name them all,

00:38:22your eye recognizes the nuances

00:38:24when you see them closely.

00:38:26cockroaches are resistant.

00:38:28They can survive in extreme conditions

00:38:30and have existed since dinosaurs

00:38:32reigned on our planet.

00:38:34But the queen of termites

00:38:36eats them raw, with a lifespan of 50 years.

00:38:38It's the biggest longevity among insects.

00:38:40Ordinary termites,

00:38:42as for them, only live 1 to 2 years.

00:38:44Some of the most powerful muscles

00:38:46of your body

00:38:48are not in your arms or legs,

00:38:50they are in your head.

00:38:52The masseter is the main muscle

00:38:54responsible for chewing

00:38:56and it must be very strong

00:38:58so that you can eat normally.

00:39:00And you know, these muscles that allow you

00:39:02to move your ears,

00:39:04these are the temporals,

00:39:06they also allow you to chew your food.

00:39:08Hens can jump

00:39:10up to 130 times the height

00:39:12of their body.

00:39:14To put this into perspective,

00:39:16imagine yourself jumping over

00:39:18the Empire State Building.

00:39:20Dogs are able to dream

00:39:22and if you have a dog,

00:39:24he's probably dreaming of you.

00:39:26Research suggests that dogs,

00:39:28like humans,

00:39:30are inspired by their daily experiences

00:39:32when they dream.

00:39:34Cucamelons,

00:39:36or mouse melons,

00:39:38look like tiny watermelons

00:39:40but at the same time,

00:39:42they have a citrus taste.

00:39:44The mantis shrimp is one of the most

00:39:46colorful creatures in the world.

00:39:48In our eyes, it looks like it has

00:39:50the colors of a rainbow,

00:39:52but for its congeners,

00:39:54it has a real explosion of colors.

00:39:56Their eyes can detect billions

00:39:58of more shades than ours.

00:40:00In Tibet, there are black diamond apples

00:40:02but dark purple.

00:40:04The place where they grow

00:40:06receives a lot of ultraviolet light during the day

00:40:08while the temperatures drop drastically

00:40:10during the night,

00:40:12making the skin of the apples

00:40:14a darker color.

00:40:16When hippos are too hot,

00:40:18they suck a pinkish liquid

00:40:20through their skin.

00:40:22This covers their bodies

00:40:24and protects them from sunburns.

00:40:26So we can say that hippos

00:40:28secrete their own sunscreen.

00:40:30The hippos are the closest

00:40:32to the T-Rex.

00:40:34Scientists have compared

00:40:36the T-Rex's DNA,

00:40:38which is 68 million years old,

00:40:40with that of 21 modern species

00:40:42and discovered that chickens

00:40:44were their closest cousins.

00:40:46Hippos are able to hold their breath

00:40:48longer than dolphins.

00:40:50They slow their heart rate

00:40:52and can stay like this

00:40:54for nearly 40 minutes.

00:40:56Dolphins have to go up to the surface

00:40:58and they don't have lungs.

00:41:00However, they have hundreds of tiny feet

00:41:02that allow them to walk

00:41:04and pump water into the star's body.

00:41:06Water acts like blood

00:41:08for the creature.

00:41:10Bees have two stomachs.

00:41:12One is used to feed them

00:41:14while the other is used

00:41:16to store the nectar they collect

00:41:18on flowers so they can bring it

00:41:20to their hive.

00:41:22Dolphins always sleep with their eyes open

00:41:24and are never completely asleep.

00:41:26This is because their breathing

00:41:28is not automatic and they have to

00:41:30keep going up to the surface to breathe.

00:41:32If they were completely asleep,

00:41:34they would simply go black.

00:41:36Humans are the only animals

00:41:38whose brain shrinks with age.

00:41:40They can even do it because of isolation

00:41:42and loneliness.

00:41:44Other animals, even some of our distant cousins

00:41:46from a branch away from the genealogical tree,

00:41:48such as monkeys and chimpanzees,

00:41:50don't have this kind of problem.

00:41:52You can taste the garlic

00:41:54with your feet.

00:41:56Rub a drop directly on your feet,

00:41:58take off your socks,

00:42:00and you'll be surprised by the effect.

00:42:02The chemical substance responsible

00:42:04for its unique smell can be absorbed

00:42:06by the skin, even if the drop

00:42:08is not in your mouth. Strange, isn't it?

00:42:10The Alps' Bouctin

00:42:12is the absolute champion

00:42:14of climbing in the animal world.

00:42:16Seas and goats seem to challenge gravity

00:42:18by climbing vertical cliffs

00:42:20where no other creature

00:42:22can evolve. Adult males,

00:42:24on the other hand, prefer flat land.

00:42:26Our lifespan

00:42:28is programmed in our cells.

00:42:30They renew and divide constantly,

00:42:32but they have a kind of internal timer

00:42:34that stops at some point.

00:42:36Some cells stop reproducing

00:42:38rather than others. On average,

00:42:40cells stop dividing

00:42:42when we reach the age of 100.

00:42:44This means that if we found a way

00:42:46to encourage our cells to stop the timer,

00:42:48we could potentially live forever.

00:42:50In any case, as long as our bank account

00:42:52allows it.

00:42:54Queen's eyes change color

00:42:56depending on the season.

00:42:58In summer, when the days are longer

00:43:00and brighter, they are brown.

00:43:02But in winter, when it gets darker

00:43:04and the days are shorter,

00:43:06their eyes turn blue.

00:43:08The blue hue helps them see in the dark

00:43:10and prevents the pressure from accumulating

00:43:12in the eye. This is due to the fact

00:43:14that pupils remain dilated for a long time

00:43:16during the dark months of winter.

00:43:18This means that they become deaf

00:43:20when they sing by tilting their heads

00:43:22backwards. This covers their auditory channel

00:43:24and acts as an integrated ear plug.

00:43:26Their singing produces

00:43:28about as many decibels

00:43:30as the noise of a trombone.

00:43:32The surface of the Earth is not uniform,

00:43:34which means that its mass is also

00:43:36unequal. Thus, gravity

00:43:38is not the same everywhere on Earth.

00:43:40There is a mysterious anomaly

00:43:42in the Hudson Bay, Canada.

00:43:44Gravity there is weaker

00:43:46than in other surrounding regions,

00:43:48and scientists believe that this is due

00:43:50to the melting of glaciers.

00:43:52During the last glacial period,

00:43:54this region was covered with ice,

00:43:56which has now melted for a long time.

00:43:58But the planet has not

00:44:00completely given up its icy burden.

00:44:02The gravity of any area

00:44:04is proportional to its mass.

00:44:06However, the glacier left a mark

00:44:08that pushed back part of the planet's mass,

00:44:10which is one of the reasons

00:44:12why gravity is weaker in this area.

00:44:14The strongest earthquake

00:44:16ever recorded

00:44:18took place in Chile,

00:44:20with a magnitude of 9.5.

00:44:22If an earthquake reached

00:44:24a magnitude of 12 one day,

00:44:26it could split our planet in two.

00:44:28When sharks need their morning coffee,

00:44:30they also go to the local café.

00:44:32In 2002, researchers discovered

00:44:34an area in the Pacific Ocean

00:44:36that they nicknamed

00:44:38the White Shark Café,

00:44:40where large white sharks come during the winter.

00:44:42They spend time together,

00:44:44tell jokes and laugh about

00:44:46the number of humans they have scared,

00:44:48then return to the coast

00:44:50to scare us a little more

00:44:52when the weather warms up.

00:44:54Sharks have three hearts,

00:44:56two of which pump blood

00:44:58to the gills and the third

00:45:00to other organs.

00:45:02Their blood is blue,

00:45:04and they also have up to nine brains.

00:45:06One is central,

00:45:08and the other eight control,

00:45:10they are the most intelligent

00:45:12on the planet.

00:45:14They hear the calls

00:45:16of their congeners

00:45:18from tens of kilometers around

00:45:20and have unique calls

00:45:22for each of their groups.

00:45:24These calls have a function

00:45:26similar to that of non-humans.

00:45:28With selfies that invade

00:45:30social networks,

00:45:32phone manufacturers had to adapt

00:45:34to the way people hold

00:45:36their phones and use

00:45:38to create a more natural look,

00:45:40which makes the image more beautiful

00:45:42so that you feel better.

00:45:44The cameras at the back

00:45:46of most phones are also

00:45:48on the left side.

00:45:50Sorry for the lefties,

00:45:52this was designed for the righties,

00:45:54who are much more numerous.

00:45:56Mount Everest may attract

00:45:58all the attention,

00:46:00but Mauna Kea,

00:46:02in Hawaii,

00:46:04is technically the highest

00:46:06in the world.

00:46:08It has a diameter of more than

00:46:103,400 kilometers,

00:46:12while Australia's width

00:46:14is almost 4,000 kilometers.

00:46:16Although it is smaller,

00:46:18the moon wins on the surface

00:46:20with more than 38 million square kilometers.

00:46:22Anatheda's phobia is the fear

00:46:24that somewhere in the world

00:46:26a duck or a gull

00:46:28can watch you.

00:46:30The person who suffers

00:46:32is not necessarily afraid

00:46:34of anything.

00:46:36It's true that a duck

00:46:38watching any of your movements

00:46:40would certainly give you

00:46:42goose bumps.

00:46:44Crows are quite good

00:46:46at recognizing people's faces

00:46:48and have even noticed

00:46:50that they remember it for a long time.

00:46:52It can be a good or a bad thing

00:46:54depending on your kindness towards them.

00:46:56You wouldn't want to run into

00:46:58a crow that hates you.

00:47:00Besides, you probably won't

00:47:02want to give them a hand.

00:47:04In the city of Yoro,

00:47:06in Central America,

00:47:08they have an annual event

00:47:10known as Fish Rain,

00:47:12which is not optional.

00:47:14Each year, in May or June,

00:47:16a torrential rainstorm

00:47:18crosses the city,

00:47:20leaving behind an incredible

00:47:22amount of fish in the streets.

00:47:24It is thought that this phenomenon

00:47:26is caused by water storms

00:47:28or water tornadoes

00:47:30that can last for thousands,

00:47:32even millions of years

00:47:34and travel from the core of the Sun

00:47:36to its surface.

00:47:38But it takes only 8 minutes

00:47:40and 20 seconds on average

00:47:42to reach your eye

00:47:44once it is at the surface.

00:47:46This means that the light

00:47:48from the Sun we see

00:47:50is very old,

00:47:52older than human beings themselves.

00:47:54There are only four words

00:47:56in the English language

00:47:58a name. It's called a spaghetto. In the Italian language, an I at the end of the word means

00:48:04that it is in the plural, while a O indicates the singular. And that goes for all types

00:48:08of pasta, like gnocchi instead of gnocchi, fettuccino instead of fettuccini, and raviolo

00:48:14for one of its divine goodness.

00:48:16Eating the sticker of an apple, peach or pear by accident should not worry you

00:48:20out of measure. They can be swallowed, even if they are not really edible. They

00:48:24will simply leave your body, like everything else. The glue used to stick them is regulated

00:48:29by the health authorities. But it is still recommended to wash the fruit and remove

00:48:33the sticker before chewing it.

00:48:35Dolphins do not only have names for each other, but they call their friends

00:48:39specifically. Which brings us to the question of knowing what names dolphins have for

00:48:43us when we go into the water. Look Frank, these bald monkeys are back

00:48:47in the water. The German chocolate cake is one of the most delicious cakes ever,

00:48:52but it has nothing to do with the country. It is named after an American baker named

00:48:56Samuel German, who invented this delicious dessert in 1852. The Eiffel Tower can be

00:49:0215 cm higher during the summer because of the thermal expansion. When the iron

00:49:07warms up during very hot days, the particles of iron expand and take even

00:49:10more space. Two planets of our solar system rotate in the opposite direction

00:49:15of the others. Venus and Uranus rotate in the opposite direction. Venus also has

00:49:19the longest day of all the planets of our solar system, since it rotates every 243

00:49:25terrestrial days. A baby macaque bears the adorable name of Puffling. To feed his

00:49:30chick, the macaque parent puts about 10 fish in his beak at the same time. While you

00:49:35sleep, you can not feel anything, even very bad or very powerful odors. Our senses

00:49:40of taste and odor are reduced by 50 to 20% during flights. This is why

00:49:44the food of planes always tastes like cardboard or is too salty. Or it's a

00:49:48very practical excuse for airlines. Look at any ad for a watch, and the time displayed

00:49:54should be 10h10. It's because of the positive effect of this position of the needles.

00:49:59It looks like a smile, and generally, the brand of the watch is directly under

00:50:03the 12. The longest English word has an incredible length of 189,819 letters. We will not

00:50:10fill them entirely here, but it is the full name of the large protein nicknamed

00:50:13titine. To say it out loud, it would take more than three hours, so take a

00:50:17seat and sit back comfortably, because we will have some for a moment. Bird, with

00:50:22its six letters, is the shortest word of the French language, which contains the five

00:50:25main vowels. Green balls can bounce higher than rubber ones. When a rubber ball

00:50:31hits a surface, it deforms before taking its initial form, and a lot of energy is

00:50:36lost in this process. A green ball does not compress at all and retains a large part

00:50:40of its energy to bounce upwards. Here's a scoop. Kangaroos can not walk

00:50:45backwards. Their long feet and their heavy tail make this movement impossible. They can

00:50:49move from side to side with incredible agility, but jumping backwards is impossible

00:50:54because of this large muscular tail. The most lonely creature on the planet is a whale

00:50:58that has been looking for a partner for a long time. Researchers identified its abnormally

00:51:03high call decades ago, and we think it never received an answer. The unknown whale

00:51:07is called lonely because it communicates at a frequency that is not used by any

00:51:11other whale in the Pacific Ocean. How sad. Meanwhile, the green bird can imitate almost

00:51:17all the sounds it hears, including that of a trombone. Australian species do not copy

00:51:21only other birds, but also other animals, such as koalas and dogs. In captivity,

00:51:26they also copy artificial sounds, such as car or truck alarms, and trombones.

00:51:31The northern hemisphere houses about 90% of the world's population. No wonder the streets

00:51:36are so crowded. The cougar has more names than any other animal, since it has

00:51:42more than 80 names. The puma, the mountain lion, the panther and the catamount are all

00:51:47the same thing. But do not confuse it with the lynx, the jaguar or the leopard. It does not

00:51:51really appreciate. Most people can not lick their own elbows. The length of the arm

00:51:56combined with the limit of flexibility of the joints makes it impossible for many.

00:52:00Your elbow is just far enough on your arm so that you can not reach it. Go ahead, try.

00:52:06That's it, time has passed. Peacocks and squirrels have beaks like birds. The beak is made

00:52:12of the same material as our nails, keratin. They can also go anywhere their beak goes,

00:52:17which makes them champions of evasion. There are more than 31 million seconds in a year.

00:52:21We recently discovered this tiny chameleon in Madagascar. With less than 2.54 cm long,

00:52:28it is the size of a seed, and could easily hold on to the tip of your finger. It is nicknamed

00:52:33the nano lizard and still proves how many tiny creatures could hide,

00:52:36without being discovered, far from the eyes of scientists and researchers.

00:53:04The Salto Rangel, the highest uninterrupted waterfall on the planet, is more than twice as high as the Empire State Building.

00:53:12During the dry season, the water that falls evaporates sometimes before reaching the ground.

00:53:17The Bloop is one of the most mysterious sounds ever heard on Earth. It occurred in 1997 and

00:53:24resembled the sounds of marine animals. But the volume was too large for a sound produced by a living creature.

00:53:30The Bloop went on for a minute. It started with a deafening rumble, then increased in frequency.

00:53:36Antarctica may look like a huge ice field, but there is actually a huge continent below.

00:53:42This means that there are volcanoes, mountains and valleys, like on any other continent.

00:53:48Scientists have recently discovered that the continental mass of Antarctica

00:53:53had the lowest point on the planet outside the oceans, as well as huge mountain ranges.

00:53:59If one of these many volcanoes erupted, it would melt a huge part of the ice on the surface

00:54:04and increase the ice floe in the ocean. The sea level would rise and flood the coastal areas of the entire world.

00:54:12The waters of the ocean would also be disturbed, which would endanger marine life.

00:54:16Fortunately, all these volcanoes are asleep for the moment.

00:54:20A day at the South Pole lasts six months on this continent.

00:54:24The South Pole has only one sunset and one sunrise over a whole year.

00:54:29Primitive Earth could have been purple and not green.

00:54:33There is a theory that says that ancient microbes used molecules other than chlorophyll

00:54:39to absorb sunlight. These molecules probably gave living organisms a purple hue.

00:54:46At the Stone Age, the total population of Central Europe was about 1,500 people,

00:54:51which means they could have held everything on a modern medium-sized cruise ship.

00:54:57Astronomers have discovered that the Milky Way weighed about 1,500 billion solar masses,

00:55:03knowing that a solar mass is the mass of our Sun.

00:55:06A very small part of this weight is made up of a supermassive black hole.

00:55:10In the center of the galaxy, 4 million solar masses and 200 billion stars.

00:55:15The rest is black, mysterious and invisible matter.

00:55:20If all the layers of ice and glaciers in the Arctic were founded at the same time,

00:55:24the sea level would rise to the height of a 26-story building.

00:55:28Under the black light, or UV, the bananas that ripen have a bright blue color.

00:55:33This is because of the chlorophyll that decomposes when the fruit ripens.

00:55:37Because of the movements of the tectonic plates, the Pacific Ocean shrinks every year,

00:55:42and the Atlantic Ocean increases in proportion.

00:55:46Today, there are only two glacial caps in the world,

00:55:49dating from the last glacial period of the planet.

00:55:52The first is the Glacier Cap of Greenland.

00:55:55The second, huge, is that of Antarctica.

00:55:58It is the size of Mexico and the United States combined.

00:56:01Tsunami waves often pass unnoticed in the middle of the sea.

00:56:04They do not rise more than a few centimeters above the surface

00:56:08until they reach shallow waters.

00:56:11But when the ocean is deep,

00:56:12they can travel as fast as a long-haul airliner.

00:56:16Corals that live in shallow waters produce their own protection against the sun.

00:56:21In them, sunlight would harm the algae that live inside them.

00:56:25To protect these algae, which are the main source of food for corals,

00:56:29they become fluorescent.

00:56:31This process allows them to make proteins that act like a solar screen.

00:56:36Nearly 90% of all volcanic activity on Earth occurs in the oceans.

00:56:41The South Pacific has the largest concentration of volcanoes we know of.

00:56:46A group of volcanoes in particular has 1,133 volcanic cones.

00:56:50They are all active and enclosed in an area the size of New York State.

00:56:55The Zemschug Canyon, in the middle of the Bering Sea,

00:56:58is the largest underwater canyon ever discovered.

00:57:01There are more treasures and artifacts at the bottom of the ocean

00:57:04than in all the museums of the world combined.

00:57:07In 1900, one of the largest hurricanes ever hit Central America and the Gulf of Mexico.

00:57:14It then continued its course to Florida and Texas.

00:57:17It is considered the most devastating hurricane in the history of the United States.

00:57:21It was detected for the first time on August 27 and lasted several days.

00:57:26When it reached the coast of Texas,

00:57:28the storm turned into a category 4 hurricane.

00:57:31Hurricanes are classified according to the speed and intensity of the winds

00:57:35using a scale called the Saffir-Simpson scale.

00:57:37There are 5 categories, ranging from 1 to 5,

00:57:401 being the weakest and 5 the strongest.

00:57:43The inhabitants of Galveston had less than 4 days to prepare for the arrival of the hurricane,

00:57:48which even went as far as Oklahoma and Kansas.

00:57:51The great hurricane then headed for the Great Plains

00:57:54and swept towards the Great Lakes, New England, and reached southeast Canada.

00:58:00The storm was so violent that more than 3,600 houses were damaged,

00:58:05even if they were strong enough to resist.

00:58:07Given the population of the time,

00:58:09this is equivalent to hundreds of thousands of houses destroyed, or even millions.

00:58:15Spotted Lake is often considered the most magical place in Canada.

00:58:19In winter and spring, it's just an ordinary lake that looks like any other.

00:58:24But try to go there in the summer, when the water starts to evaporate.

00:58:28You will have the impression of entering another world,

00:58:30a woodland landscape with blue, green, and yellow spots.

00:58:34During the summer, there are more than 300 pools here, and they all look magical.

00:58:38Over the centuries, people have believed that each of them had different curative properties.

00:58:43The explanation for these sparkling colors comes from pure science.

00:58:46Each of them has a high concentration of different minerals.

00:58:50We actually live inside the sun.

00:58:53Its atmosphere extends well beyond its visible surface,

00:58:55and even if the Earth is 150 million kilometers from the star,

00:58:59it is always close to the atmosphere of the sun.

00:59:02Polar auroras occur when charged particles from the sun

00:59:06are captured by the Earth's magnetic field

00:59:09and crash into the high atmosphere near the poles.

00:59:12The rotation speed of our planet is gradually decreasing.

00:59:16It happens at a calm rate of 17 milliseconds per slice of 100 years.

00:59:20Because of this, our days are getting longer and longer.

00:59:23And yet, it is only after 140 million years that a day on Earth will last 25 hours.

00:59:30Antarctica, the southernmost continent of the Earth, is only the fifth largest.

00:59:34But it contains nearly 70% of all the planet's fresh water

00:59:37and 90% of the world's ice.

00:59:40Antarctica is also considered a desert.

00:59:43Many rocks on Earth are of Martian origin.

00:59:46Scientists have analyzed the chemical content

00:59:49of some meteorites found in the Sahara Desert,

00:59:52in Antarctica, and in other places.

00:59:54And it turned out that these rocks came from the Red Planet.

00:59:59The world's largest sand castle is in Denmark.

01:00:02The 30 sculptors who created it used more than 5,000 tons of sand.

01:00:06To make it more durable, they added 10% clay and a layer of glue.

01:00:11They built it to resist long and stormy winters.

01:00:16Some photons that are not absorbed are re-emitted,

01:00:19and their wavelength determines the color we see.

01:00:22When you expose a material to sunlight

01:00:25or high-energy photons, it can damage its chromophores.

01:00:29That's why they can't emit photons with certain wavelengths.

01:00:33Red materials stick the most to sunlight.

01:00:36Their chromophores emit red light

01:00:38so as to cover the photons of other wavelengths.

01:00:43Every day, between 60 and 100 tons of space dust

01:00:46drift to the surface of our planet.

01:00:49These tiny cosmic particles are mainly released by comets,

01:00:53which are generally made up of dust and ice.

01:00:56When the sun turns this ice into steam,

01:00:59the remaining dust goes down to Earth.

01:01:04There are always two sides to every story,

01:01:07just like a classic cotton disc.

01:01:09Two different textures, to be more precise.

01:01:12One is smooth, and you're supposed to use it

01:01:14for the most sensitive areas of your face,

01:01:16such as your eyes.

01:01:19The rougher side can help you remove makeup

01:01:21and clean your face in less sensitive areas,

01:01:23such as the forehead.

01:01:26If you like having plants in your house,

01:01:28you've probably noticed that flower pots have holes in the bottom.

01:01:32These holes are the reason why your plant friends

01:01:35lead a happy life.

01:01:37They are extremely important for water evacuation.

01:01:40Thanks to these holes, you'll avoid accumulating stagnant water

01:01:43that can possibly harm your plant.

01:01:46In addition, thanks to the holes, the roots can develop

01:01:48and extend beyond the boundaries of your skin.

01:01:53Have you noticed that aviator sunglasses

01:01:55often have green glasses?

01:01:57This has something to do with their origin.

01:02:00They appeared in the 1930s.

01:02:03Before that, pilots had protective glasses

01:02:05to protect their eyes when they were flying.

01:02:08The high altitudes, the dazzling sun,

01:02:11and the negative temperatures were a real test for their eyes.

01:02:15The glasses helped them solve these problems,

01:02:18but there was another one.

01:02:19As the differences in temperature between the outside air

01:02:22and the inside air of the glasses were significant,

01:02:24the lenses fogged up and darkened the pilot's vision.

01:02:28The company Bausch & Lomb

01:02:30therefore designed lenses in the form of drops of water

01:02:32surrounded by a light metal frame.

01:02:35The lenses were dark green,

01:02:37because this shade eliminates blue light,

01:02:39which is also a problem for pilots

01:02:41when they fly above the cloud line.

01:02:44In addition, the green glasses reduce reflections

01:02:47and improve contrast and sharpness.

01:02:51Oh, there are holes on the side of your Converse sneakers?

01:02:55Are they really necessary?

01:02:56Well, they allow the air to penetrate into your shoes

01:02:59so that your feet stay cool.

01:03:01You can also use them to give style to your sneakers

01:03:04and tie them in different ways.

01:03:07There are two reasons why plastic bottles have streaks.

01:03:11First, if you drink water and it's hot outside,

01:03:13you will see that there is a lot of condensation on your bottle.

01:03:17Or if you do sports or weight training.

01:03:21Your hands are wet and if the bottle had a smooth surface,

01:03:24it would be more difficult to grab it.

01:03:26The streaks are there to improve your grip.

01:03:29The second reason is that thanks to these streaks,

01:03:32manufacturers can use thinner plastic.

01:03:35This means that they need less material in total production.

01:03:39And this plastic remains firm enough

01:03:41so that the bottle keeps its shape.

01:03:45Wooden coat hangers are not only there to look good.

01:03:48As they are made of cedar wood,

01:03:50they bring a pleasant scent to your closet.

01:03:52In addition, they repel insects.

01:03:54They are also super hard,

01:03:55which is convenient for heavy clothes like jackets.

01:03:58And as it is difficult to damage them,

01:04:00they will serve you longer.

01:04:04You may have noticed that there is a square of color

01:04:07at the bottom of your toothpaste.

01:04:09These blocks are usually in blue, red, iron and black.

01:04:14They are kind of markers

01:04:16because they help the machines of the assembly line

01:04:18to recognize where and when to cut the toothpaste

01:04:21and seal the end of the tube.

01:04:25Some boots have loops on the top and back.

01:04:29It may seem like a fashion effect, right?

01:04:31Or maybe it's something that manufacturers add for fun.

01:04:34But these loops are actually useful.

01:04:37They allow you to pull the shoe

01:04:38when you try to put it on.

01:04:40In addition, you can easily hang them

01:04:42or use the loop to better hold the laces.

01:04:46Time for confessions.

01:04:47Do you remember the accessories provided with your vacuum cleaner?

01:04:51You also put them aside

01:04:52and you never used them again?

01:04:55They are actually very useful when you clean the house

01:04:57because you can use them in particular areas

01:05:00that are sometimes difficult to reach with the normal accessory.

01:05:04We all know what a save is for.

01:05:07But in addition to peeling the skin of carrots or potatoes,

01:05:09you can also use it for onions.

01:05:12It may be faster than doing it with a knife

01:05:14and it will save you a few tears.

01:05:17Some sweaters have something quite special about the neck.

01:05:21A V-shaped seam

01:05:23that you can see in the middle of the neck.

01:05:26This V-shaped element,

01:05:27similar to the edges of the hem and sleeves,

01:05:29would allow the owner to put on the clothes more easily.

01:05:32And this one won't even lose its shape.

01:05:35The V-shaped piece is extendable,

01:05:36so that a person wearing the sweater

01:05:38can pass their head through the collar.

01:05:40Its purpose is also to absorb sweat.

01:05:42In its first versions,

01:05:44the green sweater had a collar at the front and at the back.

01:05:47Over time, they lost the back.

01:05:49And this V has become something decorative

01:05:52since the manufacturers began to sew a V to the collar

01:05:54without using the ribbed fabric they added before.

01:05:59The squares or shiny colored circles

01:06:01that you see on the packaging of food

01:06:03are not an indication of vitamins, minerals

01:06:05or certain aromas they contain.

01:06:08And no, it's not a secret code

01:06:10that consumers are supposed to decipher.

01:06:12It's actually for the printers.

01:06:15They are called alignment markers.

01:06:20During the printing process of the food packaging,

01:06:22the manufacturers use these color blocks

01:06:24to check if the printing ink is correct.

01:06:27They compare the color of the blocks they print

01:06:29to ensure the brand for which they work

01:06:31is of a constant and recognizable quality

01:06:33all over the world.

01:06:36Most printers use only four colors,

01:06:39yellow, magenta, cyan and black.

01:06:42Some printers have additional colors

01:06:44like green, orange and purple.

01:06:47That's why you sometimes see several circles

01:06:49on some packaging.

01:06:51They test each ink color.

01:06:55The margins in the notebooks.

01:06:56They are not there as a kind of guide

01:06:58to take notes and write.

01:07:00Someone has imagined a potential solution

01:07:02supposed to protect the written work

01:07:03against, well, the rats.

01:07:05In the past, they were quite common

01:07:07in people's homes.

01:07:09They are known for their diet

01:07:10that includes almost everything,

01:07:12including paper.

01:07:14So people started to add

01:07:16large margins like in Musgul,

01:07:18which was supposed to satiate the rats.

01:07:20So they couldn't reach the main dish,

01:07:23the written pages.

01:07:25The costumes have a buttonhole

01:07:27near the back of the neck.

01:07:29Manufacturers sew it

01:07:30so you can't open it

01:07:31without damaging your costume.

01:07:33And when you compare it to the other back,

01:07:35you see that this one is completely smooth,

01:07:37without any trace.

01:07:39You won't find a buttonhole

01:07:41as little marked

01:07:41only on a suit jacket.

01:07:43Sportswear shirts,

01:07:45jackets and other clothes

01:07:46are also provided.

01:07:48And this is linked to the history of the back.

01:07:51The first back appeared

01:07:52at the beginning of the 19th century.

01:07:54Before that, men wore mainly

01:07:56blouses with high collars.

01:07:58They buttoned them all the way up.

01:08:01During the hot days,

01:08:02they loosened the buttons,

01:08:03lowered the collars

01:08:04and left the upper button unbuttoned.

01:08:07It was a way to relieve heat

01:08:09and their folded back

01:08:10was symmetrical to the chest.

01:08:12And today we identify it as a back.

01:08:16People stopped using this buttonhole

01:08:19after the appearance of the back,

01:08:20except for certain formal occasions,

01:08:22such as when you wanted to put a flower on it.

01:08:25That's why seamstresses

01:08:26have left it as a fashion item.

01:08:29Let's talk about tea bags.

01:08:31It's easy to guess what they're for,

01:08:33but they can also be useful

01:08:34if you have feet that smell bad

01:08:35after a long day in your shoes.

01:08:37You just have to place new tea bags,

01:08:39of course, in your shoes at night.

01:08:41When you wake up,

01:08:42the tea bags will have absorbed

01:08:44all the unwanted odors.

01:08:45However, don't forget to sanitize afterwards.

01:08:47You don't want to soak a tea

01:08:48with a weird smell, do you?

01:08:49The note-takers can also have

01:08:50an additional use.

01:08:51You can pinch your money

01:08:52to keep it together.

01:08:54The same goes for the trombones.

01:08:56If your favorite bracelet breaks

01:08:58and you're looking for a way to hold it,

01:09:00a trombone can come in handy.

01:09:02You just have to hang one

01:09:03at each end of the bracelet,

01:09:05tightly twist it,

01:09:06and voila, it's ready to go.

01:09:08If it smells like fish at home

01:09:10and you haven't eaten salmon for a while,

01:09:12maybe it's time to check

01:09:14your electrical installations.

01:09:15This bad smell can mean

01:09:17that your cables are damaged,

01:09:19that your disjunctor is defective,

01:09:22or that your circuits are overheating.

01:09:24Didn't you know that these e-cables

01:09:26emit a much more unpleasant smell

01:09:28than a tuna sandwich

01:09:29forgotten in the sun?

01:09:31So call your electrician

01:09:32and have everything checked ASAP.

01:09:35But if it's a smell of rotten eggs

01:09:36floating in the air at home,

01:09:38call a plumber right away.

01:09:40Your pipes are probably contaminated,

01:09:42but you can also smell like that

01:09:45if your water heater is defective.

01:09:47Or it could still be a gas leak.

01:09:49Manufacturers add water to natural gas,

01:09:51a chemical product with an unpleasant smell,

01:09:54so that people can immediately notice

01:09:56the slightest leak.

01:09:57The next smell is not as easy to notice

01:10:00as a unicorn in Central Park,

01:10:02so listen carefully.

01:10:03Have you ever smelled a strange smell

01:10:05just before turning on your cooktop?

01:10:07It's carbon monoxide,

01:10:09and it's very important to know it.

01:10:11Because this snotty gas can be extremely dangerous

01:10:13if you inhale too much of it.

01:10:16And the worst part is that it is totally odorless.

01:10:19So what is this strange smell?

01:10:21It's actually what you add to the gas

01:10:22to warn you that a danger is lurking.

01:10:24So, the next time your cook smells bad,

01:10:27tell yourself that it may not be

01:10:28because of the lasagna from the day before.

01:10:30It is not uncommon to find mold

01:10:32in places where there is stagnant water.

01:10:35For example, when a leak is hidden behind walls.

01:10:37Mold spores can develop

01:10:39in these humid areas

01:10:41and can cause serious health problems.

01:10:44Bedspreads have a weakness for shoes.

01:10:46They love to hide,

01:10:48but only in certain conditions.

01:10:50If you have a pair of shoes

01:10:51that you almost never wear,

01:10:53be careful,

01:10:54mold spores could well be

01:10:55installed comfortably.

01:10:57But don't worry,

01:10:58there is a trick to keep

01:11:00these beasts out of your shoes.

01:11:02Leather shoes are a little too smooth

01:11:04for mold spores to slip in.

01:11:06It is therefore unlikely that you will find any there.

01:11:09Baskets, on the other hand,

01:11:10are one of the favorite places for these

01:11:13unbearable insects.

01:11:15All these interesting textures and patterns

01:11:17are perfect for hiding.

01:11:19So, if you want to prevent

01:11:21the punishes from entering,

01:11:22wear them regularly.

01:11:23They don't like to be stirred up.

01:11:25And who knows,

01:11:26you could even crush some of them

01:11:28on the way.

01:11:29It's worth a try.

01:11:30So go ahead,

01:11:31put on your sneakers

01:11:32and show them who the boss is.

01:11:34Your feet and your mental health

01:11:35will thank you.

01:11:37If your nostrils are plagued

01:11:38by an unpleasant smell,

01:11:40it may also be time

01:11:41to check your mattress.

01:11:43Recent scientific studies

01:11:44have revealed that a 7-year-old mattress

01:11:46can house more bacteria

01:11:48than a sci-fi movie

01:11:49taking place in space.

01:11:51More than 16 million units

01:11:52form colonies for 6 square centimeters.

01:11:54Enough to make the bravest of us

01:11:56want to sleep in a special suit.

01:11:59But don't worry,

01:12:00there is a solution to this problem.

01:12:03It is sodium bicarbonate,

01:12:05the unknown hero

01:12:05of housekeeping.

01:12:07Spray a little of this magic powder

01:12:09on your mattress,

01:12:10let it rest for half an hour,

01:12:11and spend the time

01:12:12with something fun.

01:12:14Cat videos work every time,

01:12:16then vacuum it.

01:12:18And there you go,

01:12:19your bed will feel fresher

01:12:20than a margarita field in the spring.

01:12:22Don't let these damn bacteria

01:12:24take over.

01:12:25And who knows,

01:12:26maybe your refreshed mattress

01:12:28will encourage you to have nice dreams,

01:12:30or at least keep nightmares away.

01:12:33Have you ever noticed

01:12:33that your towel sometimes smells

01:12:35a bit like the monster from the swamp?

01:12:36Yes, it's because you've been using it

01:12:38for too long.

01:12:39To avoid bacteria,

01:12:40change towels after three uses.

01:12:43And if you really want to ban

01:12:44these bad germs,

01:12:45use sodium bicarbonate

01:12:47from time to time.

01:12:48Your nose and,

01:12:49if you don't live alone,

01:12:50your roommates will recognize you.

01:12:53If your bathroom smells like the swamp,

01:12:55it may be because of a little stagnant water

01:12:56or a residue in your pipes.

01:12:59Don't worry,

01:13:00if the plumber can't come today,

01:13:02you can fix this problem

01:13:03by pouring a few drops

01:13:04of your favorite essential oil

01:13:06on your toilet paper roll.

01:13:08It's not a long-term solution,

01:13:10but at least you'll breathe a little better.

01:13:13Now let's move on

01:13:14to this ugly toilet brush.

01:13:15Pour a little scented detergent

01:13:17into your little bucket

01:13:18or make your own perfume

01:13:20with distilled water

01:13:21and essential oil.

01:13:23This will eliminate bacteria

01:13:24and essential oil

01:13:26will conceal bad smells.

01:13:27Just make sure

01:13:28you don't have an allergy

01:13:30to the oil of your choice.

01:13:31Did you know that mold

01:13:33can form in your dishwasher?

01:13:35Disgusting, isn't it?

01:13:36Launch a dry heat cycle,

01:13:38without a dish,

01:13:39but with white vinegar.

01:13:41Make sure to rinse the inside well,

01:13:42including the filters

01:13:43and the panels.

01:13:45And if your bucket

01:13:46looks a little dirty,

01:13:47soak it in a little

01:13:49diluted antibacterial detergent

01:13:50before rinsing it carefully.

01:13:52Now let's talk about

01:13:53the weird noises in your house.

01:13:55The clicks and bangs

01:13:56in winter or autumn

01:13:57can come from the start

01:13:59of your heating.

01:14:00If condensed steam

01:14:01is stuck in the pipes,

01:14:03try to purge your radiators.

01:14:05If you hear a boil,

01:14:06it may be a leak of water

01:14:08or sediment in your boiler.

01:14:09Turn off the main water

01:14:10and listen.

01:14:11If the noise stops,

01:14:12call the plumber.

01:14:14If this is not the case,

01:14:15try to drain the tank.

01:14:17When you move into a new house,

01:14:19check the walls and ceilings.

01:14:22Fresh paint could hide

01:14:23something.

01:14:24So ask your owner

01:14:26to estimate it.

01:14:29And avoid grainy ceilings.

01:14:31Not only are they ugly,

01:14:33but they contain laminate.

01:14:35Laminate is like a bowl

01:14:36of alphabetic pads.

01:14:38It is composed of all

01:14:39these hard-to-pronounce

01:14:40crystalline fibers.

01:14:42But beware of these crazy names.

01:14:44Laminate is a hard-to-bake.

01:14:46It can withstand high temperatures,

01:14:48chemical products

01:14:49and even electricity.

01:14:51No wonder it was used

01:14:53so much in construction in the past.

01:14:55Laminate is a rusty ninja.

01:14:57It can break down into

01:14:58such tiny fibers

01:14:59that they will float in the air

01:15:00for days and days.

01:15:02And by accidentally breathing

01:15:03these fibers,

01:15:05you let in something dangerous

01:15:06into your lungs.

01:15:07So be careful.

01:15:09Avoid laminate

01:15:09and protect your lungs.

01:15:11And be careful

01:15:12if you are renovating an old house.

01:15:13This toxic material

01:15:14could be in your roof.

01:15:16The bacteria responsible for odors

01:15:18love to party in the sink

01:15:20and in the drain of your kitchen.

01:15:22And let's not even talk

01:15:23about the hard-to-break grinder.

01:15:24A real disco for bacteria.

01:15:27But there is a fun solution.

01:15:29Once a week,

01:15:31organize your own party

01:15:32by inviting six ice cubes,

01:15:33a tablespoon of baking soda,

01:15:36three thin slices of lemon

01:15:38and a teaspoon of Javel coffee

01:15:39in your grinder.

01:15:41Turn on the music,

01:15:42turn on the grinder

01:15:43and let the ice cubes act.

01:15:45Once the party is over,

01:15:47rinse everything in cold water

01:15:48for 30 seconds.

01:15:49And there you have it,

01:15:50a clean and fresh sink.

01:15:53Your new sofa

01:15:53and your new cupboards

01:15:55could secretly release

01:15:56gaseous gases in the air.

01:15:58Yes, it's true.

01:15:5916 gases,

01:16:00called volatile organic compounds

01:16:02or COV,

01:16:03can irritate your nose

01:16:04and your throat.

01:16:05And as if that wasn't enough,

01:16:07they can even give you

01:16:08headaches and dizziness.

01:16:10Don't worry,

01:16:11I'm here for you.

01:16:13If you can,

01:16:14open your windows

01:16:15to let the fresh air circulate.

01:16:17And if you are looking for

01:16:18new furniture or objects

01:16:19for the house,

01:16:21find out about the options

01:16:22for low COV holders.

01:16:24Your nose will thank you.

01:16:25And then,

01:16:26who would like to live

01:16:27in the middle of smelly furniture?

01:16:30If you were asked

01:16:31where your stomach was,

01:16:32you would probably point to your belly.

01:16:34Sorry, but that's wrong.

01:16:36In fact, it's higher,

01:16:38hidden behind your ribs.

01:16:39Your stomach has an incredible capacity,

01:16:42it can hold up to 2 liters of liquid,

01:16:45which is the equivalent

01:16:45of a large bottle of Coca-Cola.

01:16:47It is quite difficult to estimate

01:16:49the amount of solid food

01:16:51you can swallow

01:16:52because it is treated by your teeth

01:16:53before it reaches your stomach.

01:16:55There is certainly not enough room

01:16:57for a turkey,

01:16:58but a good-sized chicken

01:16:59would probably fit.

01:17:01Speaking of organs,

01:17:02scientists think the appendix

01:17:04will eventually disappear.

01:17:06Nobody really knows

01:17:07why we need it,

01:17:08but some researchers say

01:17:10it could have existed

01:17:11to help our ancestors

01:17:12digest the bark of trees.

01:17:14As it is no longer part

01:17:15of our daily diet,

01:17:17the appendix is no longer necessary

01:17:19and can disappear from our body

01:17:21without any consequences.

01:17:22The appendix is not the only

01:17:24obsolete part of our body.

01:17:26Wisdom teeth are no longer

01:17:27very useful either.

01:17:29They were when our ancestors

01:17:31lost some of their teeth.

01:17:32But the only thing

01:17:33they help us lose now,

01:17:34well, it's the money

01:17:35we spend to extract them.

01:17:37You can easily survive

01:17:39without your appendix,

01:17:40but also without your stomach,

01:17:42kidney or lung.

01:17:43In this case, it is good to know

01:17:45that we have spare parts.

01:17:47If you never knew

01:17:48you had a personal bodyguard,

01:17:50look inside your body.

01:17:52Your liver is a safety agent

01:17:54that protects you from toxins

01:17:56and many other things

01:17:57you don't want to keep inside you.

01:17:59It is almost indestructible

01:18:01and can even regenerate.

01:18:03Your liver is a very important organ

01:18:05that works a lot

01:18:06and is responsible

01:18:07for 500 individual functions.

01:18:09Up to 10% of its content

01:18:11is made up of fat

01:18:12and it can repel.

01:18:14Even if you only have

01:18:15less than half of your liver,

01:18:16it can still regenerate

01:18:18to find its initial size.

01:18:20On average, your heart is as big

01:18:22as your fist.

01:18:23It beats 115,000 times

01:18:24and pumps about

01:18:257,500 liters of blood per day.

01:18:28The right lung is bigger than the left

01:18:30because your body must make room

01:18:31for the heart.

01:18:33You inhale many types

01:18:34of different waste,

01:18:35including 700,000

01:18:36of your own skin squam,

01:18:38and that's just one day.

01:18:39The stomach is the most important

01:18:41defender of the immune system.

01:18:43The chlorhydric acid

01:18:44present in our stomach

01:18:45kills dangerous food toxins,

01:18:47viruses and bacteria

01:18:49that are in the food

01:18:50you eat.

01:18:51This acid could digest

01:18:53the stomach itself,

01:18:54but the mucous protects it.

01:18:56You can burn calories

01:18:57when you take a hot bath,

01:18:59as much as if you were

01:19:00walking for half an hour.

01:19:01You burn between 100 and 200 calories

01:19:03per hour while standing.

01:19:04The sitting position

01:19:06burns between 60 and 130 calories,

01:19:07depending on your size,

01:19:08weight, sex and age.

01:19:11It is your own body

01:19:12that inflates and eats

01:19:13mosquito bites.

01:19:15A mosquito pierces your skin.

01:19:16Your immune system

01:19:17perceives the insect's saliva

01:19:19as a foreign substance.

01:19:21It triggers a special reaction

01:19:22to expel the intruder from your body.

01:19:25A compound produced

01:19:26by the immune system,

01:19:28called histamine,

01:19:29circulates blood more quickly

01:19:31around the bitten area,

01:19:32which causes swelling.

01:19:35Histamine also sends a signal

01:19:37to the nearest nerves,

01:19:38which causes damage

01:19:40to the bite area.

01:19:42Airplane food

01:19:43tastes slightly different

01:19:45from the one on the ground.

01:19:46It's because you lose up to 30%

01:19:48of the sensitivity

01:19:49of your taste buds

01:19:50because of the air's dryness

01:19:52and the pressure in the cabin.

01:19:54This is particularly true

01:19:55for salty and sweet foods.

01:19:57You wouldn't be able

01:19:59to taste food without saliva.

01:20:01Your taste buds

01:20:02are endowed with receptors

01:20:04that recognize different flavors.

01:20:06But they need a liquid

01:20:08to bind these flavors

01:20:09to their molecules.

01:20:10Plus, you can't taste things

01:20:12that saliva doesn't dissolve.

01:20:14You can always eat a dessert,

01:20:16whatever the amount of salad,

01:20:18soup or meat

01:20:19you've eaten before.

01:20:21Your body gets tired of the salty taste.

01:20:23But when you see

01:20:24and feel something sweet,

01:20:25like ice cream,

01:20:27cakes or chocolate,

01:20:28your brain gets excited.

01:20:29It goes beyond

01:20:30all the signs of satiety

01:20:32to promote pleasure.

01:20:33Plus, your stomach

01:20:34is a flexible organ

01:20:36and sugar helps you relax

01:20:38and make room for dessert.

01:20:41The tongue is one of the most

01:20:42powerful muscles in your body.

01:20:44This organ contains

01:20:45more than 10,000 taste buds.

01:20:47And each bud

01:20:48is endowed with microscopic hairs.

01:20:50Their job is to feel your food,

01:20:53to distinguish flavors

01:20:55and to send information

01:20:56to your brain

01:20:57to start the digestion process

01:20:59appropriately.

01:21:00Throughout your life,

01:21:01all these little bumps and ridges

01:21:03on your tongue

01:21:04create a special individual pattern.

01:21:06That's why experts say

01:21:07that tongue prints

01:21:09are as unique

01:21:10as digital prints.

01:21:12By the way,

01:21:13your tongue has no separate sections

01:21:14for bitterness, sweetness,

01:21:16acidity or saltiness.

01:21:17Each of the 8,000 taste buds

01:21:19you have on your tongue,

01:21:20palate and even throat,

01:21:21can detect all flavors at once.

01:21:24For some people,

01:21:25coriander

01:21:26may taste similar

01:21:27to soap

01:21:28because the plant contains

01:21:29a chemical product

01:21:30used in soap manufacturing.

01:21:33But only 4 to 14%

01:21:34of the world's population

01:21:35has special genes

01:21:37that can detect it.

01:21:39The masseter is the strongest muscle

01:21:41you are brought to,

01:21:42in terms of weight.

01:21:43With the rest of the muscles

01:21:44of the jaw,

01:21:45it can close your teeth

01:21:46with a force of 90 kg

01:21:48on the molars

01:21:49and 25 kg

01:21:50on the incisors.

01:21:51Your spine has an immense memory.

01:21:54It remembers your posture,

01:21:56which makes it so difficult

01:21:57to improve it.

01:21:58You owe your ancestors' chicken skin

01:22:01from a very long time ago.

01:22:02Their hair stood up

01:22:03to make them look bigger

01:22:05and more frightening

01:22:06to their enemies.

01:22:07Cats whistle

01:22:08and bark their backs

01:22:09for the same reason.

01:22:10Only 43%

01:22:11of what makes you up

01:22:13really belongs to you.

01:22:14More than 50%

01:22:15of the cells in your body

01:22:16belong to very small creatures

01:22:18that live mainly

01:22:19in your intestine.

01:22:21Yet even if your own cells

01:22:23are less numerous

01:22:24than microbial cells,

01:22:25there are on average

01:22:27about 100 trillion in your body.

01:22:29So you are never really alone.

01:22:31Keeping this in mind,

01:22:33your own genes

01:22:33represent less than half

01:22:35of what you are really made of.

01:22:37If you take all the microbes

01:22:38that live in your body

01:22:39and you count their genes,

01:22:41you will find between 2 and 20 million.

01:22:43Our size,

01:22:44the shape of our body

01:22:45and the color of our skin

01:22:47depend a lot on the place

01:22:48where our ancestors lived.

01:22:49But we can adapt

01:22:51to new conditions

01:22:52even during our own life.

01:22:54For example,

01:22:55if you go from plains to mountains,

01:22:56you will end up developing

01:22:58more red blood cells

01:22:59to compensate for the lack of oxygen.

01:23:01And naturally,

01:23:02if you go from a colder climate

01:23:03to a warmer climate

01:23:05and more sunny,

01:23:06your skin will become darker

01:23:07to adapt.

01:23:09Our lifespan

01:23:10is programmed in our cells.

01:23:12They renew

01:23:13and divide constantly,

01:23:14but they have a kind of internal timer

01:23:16that stops at some point.

01:23:18Some cells also stop

01:23:20reproducing earlier than others.

01:23:22On average, cells stop dividing

01:23:24when we reach the age of 100 years.

01:23:26If we are lucky,

01:23:28it means that if we could find a way

01:23:30to deceive our cells

01:23:31to stop the timer,

01:23:33we could potentially live forever.

01:23:36A human mouth is quite unique.

01:23:38You will not find two identical series of teeth,

01:23:41even in real twins.

01:23:42It is because the shape of the mouth

01:23:44depends on the way

01:23:45each person uses his jaw.

01:23:47Even the smallest habits

01:23:48you had several years ago,

01:23:50like biting your lips,

01:23:51affect the formation of your teeth

01:23:53and the unique character

01:23:54of your tooth imprint.

01:23:56You have probably noticed

01:23:57that the imprints of lipstick

01:23:58on a napkin or a mirror

01:24:00are always slightly different

01:24:01depending on the person who left them.

01:24:03Studies on women and men

01:24:05have revealed

01:24:06that the lip imprints

01:24:07of each individual are unique.

01:24:09They have not revealed any particular trait

01:24:11based on the sex factor.

01:24:12The lower jaw or jaw

01:24:15is the only bone of the skull

01:24:16that is not fixed to the bone that surrounds it.

01:24:18It is attached with subjunctive tissues

01:24:20and muscles.

01:24:21This is what makes it so mobile.

01:24:23You can move it in the direction you want.

01:24:25There are grafts of sensory cells

01:24:27in your tongue.

01:24:28The butterflies that are closer to the surface

01:24:30are more ephemeral.

01:24:32This is why you should not wait

01:24:34too long to be able to taste again

01:24:36after you have burned your tongue.

01:24:38The tip of your fingers is sensitive,

01:24:40but hundreds of times less than your lips.

01:24:45How can spiders survive

01:24:47when they lose a leg?

01:24:49When they are in a dangerous situation

01:24:51and they try to escape,

01:24:52they can lose their legs

01:24:54and be pushed back

01:24:55only a few months later.

01:24:56They will survive without problems

01:24:58because most of the time

01:24:59their legs detach at the point of rupture.

01:25:02These are joints

01:25:03that contain muscles that contract,

01:25:06which helps spiders

01:25:07to minimize blood loss.

01:25:09If they lose a leg

01:25:10at the level of the part

01:25:11that precedes the point of rupture,

01:25:13they will then lose more blood

01:25:14and it will be more difficult for them to heal.

01:25:17Speaking of spiders,

01:25:18have you noticed

01:25:19that they sometimes remain motionless

01:25:21for a long time?

01:25:22They freeze while waiting

01:25:23for a potential prey

01:25:25to land on their web.

01:25:26If a spider moves,

01:25:28it wastes energy

01:25:29and unnecessarily draws attention to it.

01:25:31Either a hungry bird

01:25:33in search of a snack will see it,

01:25:35or the spider will remain hungry

01:25:36because the flies will have less tendency

01:25:38to approach the web.

01:25:39When it threads a web,

01:25:41it also spends a lot of energy.

01:25:43Even when the web is finished,

01:25:45a spider may have to wait days

01:25:47or weeks before catching something.

01:25:49It is therefore important

01:25:50to save as much energy as possible.

01:25:53Hunting spiders are much more active,

01:25:55but most of them

01:25:57are nocturnal predators.

01:25:59They spend their day resting,

01:26:00hidden under a rock or in a bed.

01:26:03Roasted potatoes

01:26:05can remain hot for a very long time

01:26:07and this is due to the fatty and starchy crust

01:26:09that acts as a kind of insulating layer.

01:26:12When you boil a potato,

01:26:14these starch granules

01:26:15absorb water and swell

01:26:17until the carbon molecules escape

01:26:19to produce a kind of thick gel.

01:26:21If you then put the potato in the oven,

01:26:24the high temperature drives away the moisture.

01:26:26The gelatinized starch

01:26:28is then found outside the potato

01:26:30and creates a crispy crust

01:26:32that imprisons the heat inside.

01:26:35The fat from the baking sheet

01:26:36also accumulates in the cracks

01:26:39and the structure that keeps the heat

01:26:40remains solid.

01:26:43Birds do not electrocute

01:26:44by landing on electric lines

01:26:46because it is not the voltage

01:26:47that can harm them,

01:26:49but the difference in voltage

01:26:51without which electricity would not circulate.

01:26:54So if a bird stands on a single electric line

01:26:56at 35,000 volts,

01:26:58for example,

01:26:58the absence of voltage difference

01:27:00allows the animal to remain safe.

01:27:03But if it accidentally extends its wings

01:27:05and touches another electric line

01:27:06which has a different voltage,

01:27:08it will not end well for it.

01:27:10This is why

01:27:12electricity companies make sure

01:27:14that there is a lot of space between the cables.

01:27:18Have you ever wondered

01:27:19why plane pilots

01:27:20do not try to land on the grass

01:27:22when the landing gear is locked?

01:27:24The grass may seem like a good option

01:27:26because it is soft,

01:27:27but this surface is neither smooth nor regular.

01:27:30When the pressure is high,

01:27:31landing on the grass

01:27:32can cause unpredictable movements

01:27:34and cause problems

01:27:35such as the formation of structures

01:27:37that occur due to bounces

01:27:39and unequal pressure.

01:27:40This can even lead to a leak of fuel

01:27:42and prevent the doors from opening.

01:27:46Bald heads tend to be shiny

01:27:48whereas on the human body,

01:27:49the skin is not.

01:27:50Most of our skin

01:27:52is covered with tiny hairs

01:27:54which give it a kind of velvety look,

01:27:56a peachy hue.

01:27:57In the case of male baldness,

01:27:59the hair follicles tend to shrink

01:28:01and turn into skin cells,

01:28:03which means

01:28:04that there is no hair at all.

01:28:06The scalp is particularly shiny

01:28:08thanks to the sebaceous glands.

01:28:10They produce and secrete

01:28:11a kind of oily substance

01:28:13that protects our skin.

01:28:14The sebaceous glands

01:28:15are located all over our skin

01:28:16but the scalp

01:28:17is much more important.

01:28:19This oil therefore covers the skin,

01:28:21which turns it into a more reflective surface.

01:28:25Domestic cats

01:28:26rarely bite each other,

01:28:28but they become noisy with humans

01:28:30and this could be related to domestication.

01:28:33The domestication process

01:28:35already began

01:28:36nearly 10,000 years ago.

01:28:37Before that,

01:28:38cats were rather lonely.

01:28:40They rarely met other cats.

01:28:42So they didn't need to use their voice

01:28:44to communicate with each other.

01:28:46Instead, they communicated

01:28:47thanks to their odour,

01:28:48which included things

01:28:49like rubbing against a certain object,

01:28:51for example a tree.

01:28:53They didn't even need to meet

01:28:54other members of their species

01:28:56to send a message.

01:28:57And that's also how

01:28:58they communicate mainly today.

01:29:00But humans don't have

01:29:01as good an odour as cats,

01:29:03so these intelligent creatures

01:29:05had to find a way

01:29:06to send us messages

01:29:08while getting

01:29:08what they wanted from us.

01:29:10And that turned out to be

01:29:11the meowing.

01:29:14If you plan a day's excursion

01:29:16in a desert,

01:29:17for example the Sahara in North Africa,

01:29:20you'll want to bring

01:29:21a good sunscreen

01:29:22and a lot of water, of course.

01:29:23But also

01:29:24a well-padded sleeping bag

01:29:26if you plan to spend the night there.

01:29:28Deserts get very cold during the night.

01:29:30In the Sahara,

01:29:31the temperatures

01:29:32go from an average of 38°C

01:29:34during the day

01:29:35to minus 4°C during the night.

01:29:38This spectacular variation

01:29:39occurs because of two factors

01:29:41humidity and sand.

01:30:12In the arid deserts

01:30:13of Atacama in Chile

01:30:15and the Sahara,

01:30:16humidity is extremely low.

01:30:18This means that

01:30:19the amount of water vapour

01:30:20in the air is almost zero.

01:30:22But unlike sand,

01:30:24water keeps the heat well.

01:30:26The water vapour in the air

01:30:27traps the heat near the ground.

01:30:29It's as if you were covering

01:30:31the ground with a huge blanket.

01:30:33This prevents it from dissipating

01:30:34in the atmosphere.

01:30:35In addition,

01:30:36when the air has a high humidity level,

01:30:39it needs a lot of water

01:30:41and a lot of energy

01:30:42to warm up.

01:30:44This means that

01:30:45it takes more time

01:30:46for this same energy to disappear

01:30:48and for the environment to cool down.

01:30:50As there is almost no humidity

01:30:52in the deserts,

01:30:53these areas can both

01:30:54warm up and cool down quickly.

01:30:58If you heat your tea in the microwave,

01:31:00it will taste less good

01:31:01than when it is prepared

01:31:02with a kettle.

01:31:04This is because the temperature of the liquid

01:31:05is the main factor

01:31:07of a good tea.

01:31:08The water must reach boiling point

01:31:10for a while

01:31:11before you pour it

01:31:12on the tea leaves.

01:31:14Whether in a jar or in a bag,

01:31:16it is rather easy to do

01:31:17with tea kettles,

01:31:19whether electric

01:31:20or on the stove.

01:31:21When the burner

01:31:22or the heating element is on,

01:31:24the water at the bottom of the container

01:31:26warms up.

01:31:27And as it warms up,

01:31:28the water in the rest of the kettle

01:31:29reaches boiling point.

01:31:31Conversely,

01:31:32a microwave does not heat

01:31:33from the bottom up.

01:31:34It creates electromagnetic waves

01:31:36that jump randomly

01:31:38around the oven.

01:31:39You probably noticed it

01:31:40when you tried

01:31:41to heat up leftovers.

01:31:42They end up being partially cold

01:31:44in some places

01:31:45and very hot in others.

01:31:47The same thing happens with water,

01:31:49because it is difficult

01:31:50to control the energy

01:31:51of the microwaves.

01:31:52A liquid that is too hot

01:31:53is not good for tea either.

01:31:56When the water exceeds 100°C,

01:31:57which is its boiling point,

01:31:59it can destroy the compounds

01:32:01that give a tea

01:32:02its specific flavour.

01:32:05Have you ever wondered

01:32:06why American power outlets

01:32:08have holes in their plugs?

01:32:10The story goes back

01:32:11to the early 20th century,

01:32:13when Harvey Hubbell Jr.

01:32:15invented different types

01:32:16of electrical outlets.

01:32:17He started with the detachable

01:32:19electrical outlet,

01:32:20which was the very first

01:32:21of its kind.

01:32:22Some of his designs

01:32:24had plugs with notches

01:32:26that aligned with the small bumps

01:32:28inside the electrical outlets.

01:32:30This system of notches

01:32:31and bumps

01:32:32kept the plugs in place

01:32:34when people inserted

01:32:35a plug into an outlet.

01:32:37At one point,

01:32:38these notches gave way

01:32:40to holes that function

01:32:41in the same way.

01:32:42But that's only part of the story.

01:32:44Most modern plugs

01:32:46no longer have notches.

01:32:47They prevent the plugs

01:32:49from falling off the wall

01:32:50by using friction and pressure.

01:32:52Today, some manufacturers

01:32:53insert a plug

01:32:55into all the holes

01:32:55of a line of forks.

01:32:56This is how they keep them in place

01:32:58while wrapping them in plastic.

01:33:00Some also say

01:33:01that the holes

01:33:01save metal,

01:33:03which reduces

01:33:04manufacturing costs.

01:33:07Can you hear a sound

01:33:09and almost instantly perceive

01:33:11a specific color?

01:33:13You could be part

01:33:14of a particular group of people,

01:33:16about 4% of the world's population,

01:33:19capable of experiencing synesthesia.

01:33:21It's not you who imagines things.

01:33:24A new study

01:33:24tries to show

01:33:25that synesthesia is very real,

01:33:27and brain scanners

01:33:29prove it.

01:33:29When these synesthetic people

01:33:31hear colors,

01:33:33scans reveal

01:33:34that parts of their brain

01:33:35linked to sight and sound

01:33:37communicate with each other.

01:33:39Since synesthesia

01:33:41seems to be of a genetic nature,

01:33:43some researchers

01:33:44chose three families

01:33:45where this feature was present.

01:33:48They then played

01:33:49with DNA sequencing

01:33:51and compared the genes

01:33:52of synesthetic members

01:33:53of the same family

01:33:54to those who were deprived of it.

01:33:56They still haven't completely

01:33:58identified this unique feature,

01:34:00but they have managed

01:34:01to restrict it

01:34:02to as few as 37 possible genes.

01:34:05Sometimes, after a nap

01:34:06in an uncomfortable position,

01:34:08you may have felt tingling

01:34:10or a tingling in your arm

01:34:11or your leg.

01:34:13You might think

01:34:14it has everything to do

01:34:15with poor blood circulation.

01:34:17But in fact,

01:34:18it could be due to a little thing

01:34:20called paresthesia.

01:34:22It's when your body

01:34:23begins to feel unusual sensations

01:34:26because your nerves

01:34:27are compressed or irritated.

01:34:29Paresthesia can give you anything,

01:34:31from a burning sensation

01:34:32to this annoying sensation

01:34:34that your arm

01:34:35or your leg

01:34:36no longer responds at all.

01:34:37It could even add

01:34:38tingling

01:34:39or these good old

01:34:40characteristic tingling.

01:34:42Normally,

01:34:42it shouldn't take you

01:34:44more than 30 minutes.

01:34:46Shake vigorously

01:34:47the affected part of the body

01:34:48and it could speed up the process.

01:34:51If it lasts longer

01:34:52or if you have repeated episodes

01:34:54of paresthesia for no apparent reason,

01:34:56it is preferable to consult

01:34:58a specialist

01:34:59to make sure everything is fine.

01:35:01Do you know what is also worth

01:35:03being checked?

01:35:04If you have already given

01:35:05a blue thumb to this video

01:35:07and if you are subscribed to the channel.

01:35:09You know,

01:35:10just to be sure

01:35:11not to miss anything.

01:35:14In normal time,

01:35:15you never think about your stomach

01:35:17or all the chemistry it contains.

01:35:19Can you imagine

01:35:20if one day this substance

01:35:22simply disappeared?

01:35:23It contains chlorhydric acid

01:35:25which is also used

01:35:27in fertilizers,

01:35:28rubber and steel.

01:35:31If you inhale it,

01:35:32you will have serious breathing problems

01:35:34and in your nose.

01:35:36Every time you chew something,

01:35:38your stomach begins to produce

01:35:39these gastric juices.

01:35:41They are useful

01:35:42because they can break down proteins,

01:35:44activate pepsin,

01:35:45eliminate all the bacteria

01:35:47that you have been able to swallow

01:35:47without even knowing it

01:35:49and signal to your food

01:35:51to go...

01:35:52well...

01:35:53to the exit.

01:35:55Without this acid,

01:35:56the food would stay right there,

01:35:58transforming itself

01:35:59into a breeding ground

01:36:00for bacteria.

01:36:02Proteins and nutrients

01:36:03would not be absorbed by it.

01:36:05Your breakfast could quickly go

01:36:07as it did

01:36:07through your digestive system

01:36:09and you would end up

01:36:10expelling undigested food.

01:36:14There is a reason

01:36:15why paper cuts

01:36:17hurt so much.

01:36:18To begin with,

01:36:19they occur

01:36:20on the tip of your fingers

01:36:22which are very sensitive areas.

01:36:24It is because they are full of receptors

01:36:26which are like the receptionists

01:36:28of your body,

01:36:29helping you determine the size,

01:36:31the shape,

01:36:32the texture

01:36:33and the temperature

01:36:34of the things you touch.

01:36:36When you cut yourself with paper,

01:36:38these receptors are instantly solicited,

01:36:41sending unpleasant information

01:36:43to the brain.

01:36:44Paper cuts

01:36:45do not look like a sharp cut

01:36:47made with a sharp knife

01:36:49because of the foam

01:36:50on the edges of the sheet.

01:36:52This exposes your receptors even more.

01:36:55Paper cuts do not bleed much

01:36:57and do not coagulate well either,

01:36:59which leaves the nerves alive

01:37:01and aggravates the discomfort even more.

01:37:04We always use our hands,

01:37:06so these cuts continue to reopen,

01:37:09taking an infinite amount of time to heal.

01:37:11Paper is often treated

01:37:13with chemicals

01:37:14that can irritate your skin.

01:37:18The déjà vu seems to strike from nowhere,

01:37:20you are not a wizard

01:37:22and you do not communicate

01:37:23with the spirits of the beyond either.

01:37:26It is simply your brain

01:37:27that works badly.

01:37:29According to doctors,

01:37:30déjà vu occurs

01:37:31when two parts of the brain

01:37:33have a little trouble understanding each other.

01:37:35These two parts are located

01:37:36on each side of your skull,

01:37:38just above your temples.

01:37:40They are a bit like

01:37:41the memory cards of your brain

01:37:43and help you remember certain things

01:37:45like places

01:37:46or the faces of other people.

01:37:49They even disconnect emotions

01:37:51and are in charge of language.

01:37:53Now,

01:37:54in each of these areas of the brain,

01:37:56which are called temporal lobes,

01:37:57there is a region called the hippocampus.

01:38:00It is responsible for short-term memory.

01:38:03Sometimes,

01:38:04the brain can encounter small malfunctions,

01:38:07confusing the hippocampus.

01:38:09It is then that we feel the déjà vu.

01:38:12This whole process disturbs

01:38:13your memory of recognition,

01:38:15giving you this strange feeling

01:38:17that you have already been there before,

01:38:20or that you have already met a person

01:38:22that you see for the very first time.

01:38:24It is a completely normal process

01:38:26and you are more likely to experience the déjà vu

01:38:29if you are between 15 and 25 years old.

01:38:32It also seems that people who travel a lot

01:38:35or have the ability to remember their dreams

01:38:38feel it more often.

01:38:41It is difficult to imagine

01:38:43that an entire civilization

01:38:45can survive without anyone being able to see.

01:38:48This seems highly improbable

01:38:50and here is why.

01:38:52First,

01:38:53imagine trying to cultivate crops

01:38:55without even being able to see what you are doing.

01:38:58The preparation of the soil would become a nightmare

01:39:01because, without sight,

01:39:02we would get lost in the first field of wheat

01:39:04without any reference point.

01:39:07Harvesting just a little of this food

01:39:09would not be an easy thing either.

01:39:11Animals could be hiding

01:39:13everywhere ready to harm us.

01:39:15Communication would be as complicated

01:39:17because we would not be able to read something

01:39:20without touching it.

01:39:22Even our social lives would be different.

01:39:25Without sight,

01:39:26we should be proud of our voices.

01:39:28Confide in someone without knowing who else is listening.

01:39:31Thank you.

01:39:33If you have ever eaten a very spicy pepper,

01:39:36you know that it is not technically hot.

01:39:38In terms of temperature.

01:39:40So why do we feel like it is burning us

01:39:43even if it just came out of the refrigerator?

01:39:46Well, spicy foods contain chemical compounds

01:39:49that deceive our body

01:39:51to alter its internal thermostat.

01:39:54First,

01:39:55our lips and tongue feel like they are on fire.

01:39:58Then,

01:39:59our nose starts to run,

01:40:01and we can even shed a tear.

01:40:03Or two.

01:40:04The blood vessels dilate.

01:40:06And suddenly,

01:40:07our body temperature increases.

01:40:09To cool things down,

01:40:11we start to sweat.

01:40:13Our lungs can also participate

01:40:15and signal to our diaphragm to produce hockeys

01:40:18in order to chase this irritating intruder.

01:40:21In most cases,

01:40:23all these bodily triggers are caused by a substance called

01:40:26capsaicin,

01:40:28often found in strong peppers

01:40:30like habanero and cayenne pepper.

01:40:34Even if we sometimes feel like moving while we are dreaming,

01:40:37this is not the case thanks to a complex system in our body.

01:40:41It prevents our muscles from doing all kinds of extravagant things

01:40:45related to crazy stories

01:40:46that our brain could invent during the night.

01:40:49It turns out that most of this brain chemistry

01:40:51happens during the paradoxal sleep phase,

01:40:54or REM,

01:40:55about 90 minutes after you fall asleep.

01:40:59During this phase,

01:41:01your brain knows some of the strangest dreams,

01:41:04while your voluntary muscles,

01:41:06like your arms and legs,

01:41:07are deactivated.

01:41:09This muscular blockage is the reason why some people wake up

01:41:13and cannot move,

01:41:14experiencing what is called sleep paralysis.

01:41:18The great mystery was to know how the muscles entered this state of paralysis.

01:41:23At first,

01:41:23researchers thought that glycine,

01:41:25a neurotransmitter,

01:41:27was responsible for it.

01:41:29Research has shown that even if we block the production of glycine,

01:41:33the muscles remain frozen.

01:41:36It took a little more time for scientists

01:41:38to discover that in order to maintain these immobile muscles,

01:41:41we need both glycine

01:41:43and another chemical substance for communication,

01:41:46called GABA.

01:41:49We are not as hairy as our ancestors,

01:41:51but we still have the skin of a hen when we are cold.

01:41:54It is because of these small muscles in our hair follicles,

01:41:57called hair erector muscles,

01:42:00that pull them up.

01:42:02For furry animals,

01:42:04this feature helps them stay warm,

01:42:07but for us,

01:42:08it does not accomplish much in terms of heat.

01:42:10However,

01:42:11we and a few other less hairy creatures

01:42:14have maintained this ability over the years.

01:42:17Experiments have been carried out to find out more about this hen's skin.

01:42:21We found three key factors.

01:42:23These hair erector muscles,

01:42:25sympathetic nerves,

01:42:26and hair follicles.

01:42:28When we tried to influence the nerves,

01:42:30the hair growth slowed down.

01:42:33These nerves and our hair follicles work together,

01:42:36creating chemical synapses.

01:42:39Thus,

01:42:39hen's skin is not just a quick solution to overcome a low temperature.

01:42:44It could also communicate

01:42:46to our stem cells to grow more hair in the long run.

01:42:50This is why the loss of these muscle cells could be linked to baldness.

01:42:56And no,

01:42:57it is not possible to see the Great Wall of China from space.

01:43:00It is a myth that leaves us thinking,

01:43:02but it is nothing more than a received idea.

01:43:04NASA has confirmed it,

01:43:05and now you know it too.

01:43:07Yet the wall is a magnificent place.

01:43:09And today is your lucky day.

01:43:11We are going to take you there.

01:43:12So buckle up.

01:43:14We are going to China,

01:43:15the largest country in Asia

01:43:16and the third largest territory in the world.

01:43:18And with its more than 1.3 billion inhabitants,

01:43:21it is still the most populated country today.

01:43:24Even if India is approaching it

01:43:25and will probably soon take the first place.

01:43:30China is also one of the oldest nations in the world,

01:43:33with 3,500 years of uninterrupted history.

01:43:36But civilization already existed before that.

01:43:40Historians believe that China was not populated

01:43:43by colonists from elsewhere.

01:43:45Chinese civilization is very likely formed

01:43:48from the local populations of the Stone Age,

01:43:50who lived on this territory since prehistory.

01:43:53It is therefore not surprising that the country is full of history

01:43:55and ancient monuments.

01:43:56And we are going to show you a few.

01:43:59We are at the Great Wall.

01:44:01It is more than 21,000 km long,

01:44:03almost five times the distance

01:44:05that separates New York from Los Angeles.

01:44:07Or even a little longer

01:44:08than the distance between the North Pole and the South Pole.

01:44:12It's impressive in itself, even in our time.

01:44:14Of course, it did not happen overnight.

01:44:16In fact, the wall was erected over the centuries.

01:44:20You probably know that the ancient cities

01:44:21were surrounded by ramparts

01:44:23to protect their inhabitants from invaders.

01:44:25Well, the Chinese cities also had one.

01:44:27The first emperor of China unified the country

01:44:29in 220 BC

01:44:31and had an idea as brilliant as ambitious.

01:44:34Transform all the walls of all the cities

01:44:36into a gigantic wall

01:44:38that would defend the border of the empire.

01:44:40This is how the process began.

01:44:42And at first, the wall was made

01:44:44only of beaten earth and wood.

01:44:46Each successive emperor

01:44:47resumed the project of the Great Wall,

01:44:49strengthening it, extending it

01:44:50and repairing it as he went along.

01:44:52But also bringing each time

01:44:53more modern construction techniques.

01:44:55Some favored bricks to erect the wall,

01:44:58others blocks of granite and marble.

01:44:59The towers and platforms

01:45:01did not exist either at first.

01:45:02They were added 19 centuries

01:45:04after the start of construction.

01:45:06The wall is therefore not very homogeneous

01:45:08in terms of material.

01:45:09But this only adds to its charm

01:45:11and shows the time and effort

01:45:13that it took.

01:45:15You can notice that some bricks

01:45:16have engraved inscriptions.

01:45:18They were left by the workers

01:45:20in charge of these works.

01:45:21These inscriptions were intended

01:45:23to guarantee quality.

01:45:24They contain a mine of information

01:45:25such as the location, the quality of the stone

01:45:27and the officials responsible for the construction.

01:45:30Thus, in case of problems

01:45:31related to the material or the design,

01:45:32we knew right away who was responsible.

01:45:36Do not forget either that the wall is toxic.

01:45:39To prevent it from being attacked by insects,

01:45:42arsenic, a famous poison,

01:45:43was included in its construction.

01:45:46It is therefore better not to lick it.

01:45:47Sometimes kill this kind of weird lupine.

01:45:49Construction stopped

01:45:51at the end of the 19th century

01:45:52because the wall had lost

01:45:53its strategic and military importance

01:45:55due to technological progress

01:45:57by the world.

01:45:59The walls of encyclopedias

01:46:00are much less practical than before.

01:46:02Their efficiency is still close to zero.

01:46:04Construction therefore lasted more than 2,000 years,

01:46:07which still makes it

01:46:08the longest construction project in the world.

01:46:12Alas, today the Great Wall

01:46:14looks rather pale.

01:46:16It is estimated that only 8% of these walls

01:46:18are still in good condition,

01:46:19the rest being considerably damaged.

01:46:22In addition, about a third of the wall

01:46:24disappeared without a trace

01:46:26due to natural erosion

01:46:27and damage caused by man.

01:46:29In addition, many bricks

01:46:30were removed from the wall

01:46:31during the last century

01:46:33to be used in the construction

01:46:34of farms and houses.

01:46:35Today, the wall is still

01:46:37deconstructed stone by stone,

01:46:39but this time by tourists.

01:46:41Many of them

01:46:42tear a stone from it

01:46:43as a souvenir.

01:46:45It makes a lot of stones,

01:46:46knowing that more than 50 million tourists

01:46:48visit the Great Wall every year.

01:46:51So we will not take any memories

01:46:53of our trip today,

01:46:54but we will simply keep the memory.

01:46:57Now let's visit the Forbidden City.

01:47:00It is an imperial palace

01:47:01whose construction lasted 16 years

01:47:03and was completed 600 years ago.

01:47:06Today it is still the largest palace in the world.

01:47:08It has 980 buildings

01:47:11and more than 8,000 rooms.

01:47:13Why is it called Forbidden City?

01:47:15Well, centuries ago,

01:47:16people like you and me

01:47:17could not walk

01:47:19in the streets of this city

01:47:20because it was considered

01:47:21a sacred place

01:47:22destined to shelter the emperor.

01:47:24No one could enter or leave the city

01:47:26without his permission.

01:47:28Today, the Chinese call it

01:47:30more often the Old Palace,

01:47:31well, the equivalent in Mandarin

01:47:33that we will not even try to pronounce.

01:47:36Its design is not at all due to chance.

01:47:39Its details reflect

01:47:40the traditional Chinese architecture

01:47:42and even the colors are chosen

01:47:43in accordance with the Feng Shui philosophy.

01:47:46The roofs of the city are yellow,

01:47:48which represented

01:47:49the supreme power of the emperor.

01:47:51Most of the walls

01:47:52and pillars of the city are red,

01:47:54representing fire,

01:47:55earth and robustness.

01:47:58The floors are made of gold bricks.

01:48:01It is not gold to talk about,

01:48:03but surprisingly,

01:48:04they are just as precious.

01:48:06It is very difficult to make them

01:48:07and especially to reproduce

01:48:08this ancient technique.

01:48:10Two original slabs of the Forbidden City

01:48:12were sold for 800,000 yuan,

01:48:15or 106,000 euros.

01:48:19You can also see

01:48:20statues of animals on the roof.

01:48:22Just like the colors,

01:48:23they carry a meaning

01:48:24in Chinese culture.

01:48:25Dragons, phoenixes and lions

01:48:27are the most powerful.

01:48:29Dragons symbolize strength

01:48:30and good fortune

01:48:31and occupy a central place

01:48:32in this culture.

01:48:33They appear everywhere,

01:48:34in Chinese idioms,

01:48:36legends, astrology, art, etc.

01:48:39In ancient China,

01:48:40emperors were considered

01:48:41as sons of dragons.

01:48:43It seems that the Targaryens

01:48:44of Game of Thrones

01:48:45are not the only ones after all,

01:48:46and that ordinary people

01:48:48did not even have the right

01:48:49to hold objects

01:48:49to the dragon's effigy.

01:48:51As for the phoenix,

01:48:51in Chinese mythology,

01:48:52its rare appearance

01:48:53when it ascended the throne

01:48:54of a new emperor

01:48:55was a sign of good luck.

01:48:58In the Feng Shui,

01:48:59it is also a symbol of good luck,

01:49:01and when it is used

01:49:02in a good way,

01:49:03it is supposed to bring

01:49:04a positive energy to the house.

01:49:06Lions, on the other hand,

01:49:07are synonymous with strength

01:49:08and power.

01:49:09They are always found in pairs,

01:49:10a male and a female,

01:49:11and they are the guardians of the place.

01:49:13The number of statues of animals

01:49:14on the roof

01:49:15is enough to indicate

01:49:16the importance of the building.

01:49:19The city is made of wood

01:49:20and without any nails.

01:49:22These were associated with violence

01:49:23and have never been welcome.

01:49:25You can imagine

01:49:26that a city made of wood

01:49:27presents serious risks of fire.

01:49:29A small spark would be enough

01:49:30for the city,

01:49:31whose history dates back six centuries,

01:49:33to be quickly reduced to ashes.

01:49:34The prevention of fires

01:49:35is therefore taken very seriously.

01:49:38The Forbidden City

01:49:39has a variety of equipment

01:49:40to fight fires,

01:49:42and there is even

01:49:42a special fire brigade

01:49:44that knows the plan of the city

01:49:45like the back of its hand

01:49:46and that monitors it every day.

01:49:50As you walk around the city,

01:49:51you will notice something

01:49:52quite unusual.

01:49:54No birds ever land on these roofs.

01:49:57During the construction of the city,

01:49:59birds were taken care of

01:50:00and the engineers erected

01:50:01these roofs in a special way

01:50:03so that no bird

01:50:05can land where it stays.

01:50:07The edges of the roofs

01:50:08are wider than the claws of the birds

01:50:10and the slope of each is elevated.

01:50:13In addition, the roofs are made of sliding tiles,

01:50:15so that the volatiles

01:50:17can't stay there at all.

01:50:19What do they do against the birds?

01:50:21Well, in this way,

01:50:22the city remains cleaner

01:50:23and more majestic.

01:50:26There are certainly no birds,

01:50:28but there are more than 100 cats

01:50:29roaming the city.

01:50:31They also play an important role

01:50:33in this story.

01:50:34Some of these cats

01:50:35come directly from the imperial family,

01:50:37seen two of the dynasties

01:50:38that occupied the Forbidden City

01:50:40had cats.

01:50:42These dynasties then collapsed,

01:50:44but the cats stayed in the city

01:50:45and lived there since then.

01:50:47Of course, some stray cats

01:50:48joined the imperial family

01:50:50over the years,

01:50:51but no one cares about it

01:50:52and no DNA test was carried out

01:50:54to determine which one

01:50:55could be an authentic Aristocat.

01:50:57After all, they all roam the city

01:50:59in the same way,

01:51:00hunt mice

01:51:01and maybe some stray birds

01:51:02and protect the city.

01:51:04All cats are therefore welcome.

01:51:07Stand up!

01:51:08A new day begins

01:51:10in the Victorian era.

01:51:12Here is Daphne,

01:51:13a typical 19th-century Londoner.

01:51:16She and her husband John

01:51:17are ordinary people of that era.

01:51:19Despite the rumors of the 21st century,

01:51:22they did not get married so young.

01:51:24In fact, at the time,

01:51:25few people got married

01:51:26before the age of 22.

01:51:28It would be much easier to get up

01:51:30if it was not so cold in their house.

01:51:33Daphne and John are not very rich,

01:51:35so they could not afford

01:51:37the Victorian-style central heating,

01:51:39which consists of a coal chimney

01:51:41with iron grids.

01:51:43However, even the weaker classes

01:51:45who are equipped with it

01:51:46do not particularly want to turn it on

01:51:48because this type of heating

01:51:49is quite expensive.

01:51:51So the only thing that prevents Daphne

01:51:53and the other Londoners

01:51:54from freezing in their house

01:51:56is an old carpet.

01:51:57Yes, you really don't want to walk

01:51:59on this bare floor.

01:52:01To top it all off,

01:52:02due to the total absence of ventilation

01:52:04in the rooms,

01:52:06the air of all Victorian houses

01:52:08is quite suffocating.

01:52:09Doctors therefore recommend

01:52:10opening the windows during the night

01:52:12to let out all the bad smells.

01:52:15Daphne usually wakes up alone

01:52:17because her husband works at the factory

01:52:18and must be punctual.

01:52:20To do this,

01:52:21he calls the help of the knocker-uppers.

01:52:23These people walk around the streets

01:52:25early in the morning

01:52:26and simply knock on the windows' tiles.

01:52:29It is a rather economical alternative

01:52:30to watches and clocks.

01:52:32To start your day on the right foot,

01:52:34with a toilet,

01:52:36all Daphne needs

01:52:38is a bowl,

01:52:39a bucket,

01:52:40a piece of fabric

01:52:41and soap.

01:52:42The main ingredient

01:52:44is a hot water jug

01:52:45to make this morning routine

01:52:47more pleasant.

01:52:48In addition,

01:52:49the Victorian soap

01:52:50simply does not foam in cold water.

01:52:53A little tip,

01:52:54it is simpler

01:52:55and less freezing

01:52:56to wash your body

01:52:57part by part.

01:52:59As for cosmetic care,

01:53:00it is obvious

01:53:01that there was no manicure salon.

01:53:04But even if there was,

01:53:05it would not have been very popular

01:53:07with the women of the working class.

01:53:09Pink nails

01:53:10and soft skin

01:53:11were signs of oasis,

01:53:13which were not at all

01:53:14in the taste of the day.

01:53:15On the contrary,

01:53:16the noble ladies of the Victorian era

01:53:18had certain rules for their nails.

01:53:20No spots or scuffs,

01:53:22the nails had to be oval

01:53:24and no color was allowed.

01:53:26While the ladies

01:53:28used lemon

01:53:29to protect their hands

01:53:29from rust spots,

01:53:31proletarian women

01:53:32like Daphne

01:53:33opted for soft skin

01:53:34to soften their skin.

01:53:36Daphne

01:53:37and many other Victorian women

01:53:39worked from home.

01:53:41No, she does not have to answer

01:53:42a dozen calls on Zoom every day,

01:53:44but she is rather good at sewing,

01:53:46so that she can work in a nightdress

01:53:48like many people do today.

01:53:50Unlike his wife,

01:53:52John works 16 hours a day

01:53:53in a factory

01:53:55and this is quite normal

01:53:56for the Victorian era.

01:53:58But if he were a lawyer,

01:53:59for example,

01:54:00he would work less,

01:54:01from 8 to 19 hours.

01:54:03As for the bourgeois,

01:54:04they generally devoted themselves

01:54:05to their business

01:54:06from 10 to 16 hours.

01:54:09Without a mobile phone,

01:54:10John can't really order an Uber

01:54:12and therefore has to walk

01:54:13the 6-kilometre trail

01:54:15to go and come back from work

01:54:17every day.

01:54:18Instead of taxis,

01:54:19there were horse-drawn carriages.

01:54:21But these routes

01:54:22could sometimes hurt people

01:54:24due to the lack of suspension,

01:54:26especially since the seats

01:54:27were narrow and uncomfortable.

01:54:29There were also omnibuses

01:54:31pulled by horses,

01:54:32but passengers often complained

01:54:34that as soon as the horse stopped,

01:54:35for a yes or for a no,

01:54:37he could be easily

01:54:38thrown onto the ground.

01:54:40Do you skip breakfast

01:54:42or do you grab something

01:54:43before leaving,

01:54:45like John does?

01:54:46If this is the case,

01:54:47you have this in common

01:54:48with the workers

01:54:49of the Victorian era.

01:54:51Their breakfast

01:54:52often depended on the accessibility

01:54:54of their workplace.

01:54:55If it was easily accessible by foot,

01:54:58they could share

01:54:59a quick breakfast

01:55:00with their family.

01:55:01Otherwise,

01:55:02breakfast was quite quick

01:55:04and rather frugal.

01:55:06So we're going to give you

01:55:07a little quiz

01:55:08about the typical Victorian breakfast

01:55:10of the working class.

01:55:12A. A toast with avocado

01:55:14accompanied by a smoothie.

01:55:15B. A croissant and a cappuccino.

01:55:18C. A piece of bread

01:55:20and a foamy drink

01:55:21made from barley.

01:55:23Yep, it's bread

01:55:24or sometimes porridge,

01:55:25depending on the region of England

01:55:27where you worked.

01:55:28And this barley-based drink

01:55:29is better known as beer,

01:55:32which was thought to be

01:55:33full of essential vitamins

01:55:35for another hard day's work.

01:55:37In addition,

01:55:38it didn't require any cooking,

01:55:40a kind of Victorian fast food.

01:55:43However,

01:55:44many people preferred tea,

01:55:45and coffee and cocoa

01:55:47also began to gain popularity

01:55:49at the time.

01:55:50On the way to work,

01:55:52John gets hit by a whip.

01:55:54Oh, I just have to go get changed then.

01:55:56There's nothing better

01:55:57than wearing a fresh shirt

01:55:59with a sip of this flowery perfume

01:56:01softener, he thinks.

01:56:03No, I'm kidding.

01:56:04There was no perfumed softener

01:56:06at the time.

01:56:07His wife, Daphne,

01:56:08never heard of a washing machine,

01:56:11no more than a softener.

01:56:12And people loved to do the laundry

01:56:14at the time.

01:56:15The main reason for this lack of popularity

01:56:17was that this process

01:56:19could take up to three days.

01:56:21Anyone who had the means

01:56:22would certainly pay someone else

01:56:24to do it.

01:56:25Problem number one,

01:56:27no hot water in the houses.

01:56:29Problem number two,

01:56:30when people heated water

01:56:31for their laundry,

01:56:33this would take up

01:56:33the entire kitchen of the house.

01:56:35No more free space in the kitchen.

01:56:38Laundry always began

01:56:40by inspecting the clothes

01:56:41to see if they were not clogged

01:56:43in order to put them back in place

01:56:44before this vigorous washing process.

01:56:47Then the clothes had to be soaked.

01:56:50Saturday was generally

01:56:51the day of soaking.

01:56:53This process could take hours

01:56:55because some substances,

01:56:56such as mud,

01:56:57easily dissolved in water.

01:56:59John was lucky,

01:57:01but others needed more time.

01:57:03The only solvent available

01:57:05was household soap.

01:57:07On Monday morning,

01:57:08the clothes were well soaked

01:57:10and ready to be washed.

01:57:11Some people used soap

01:57:13on places where grease

01:57:14tended to accumulate,

01:57:16such as glue,

01:57:17but the soap remained quite expensive.

01:57:19Then came the washing,

01:57:22drying,

01:57:22and spreading of all this laundry

01:57:24to dry it.

01:57:25Earlier,

01:57:26the clothes could be reused

01:57:29on Tuesday.

01:57:29This procedure was applied to cotton,

01:57:31which was a bit more difficult

01:57:33to do with wool.

01:57:35And imagine washing

01:57:36delicate clothes at the time,

01:57:38such as corsets, for example.

01:57:40Tight corsets, by the way,

01:57:42were not so popular

01:57:44in the Victorian era.

01:57:45Of course, some people

01:57:46were convinced

01:57:47that a waist size

01:57:49could only be achieved

01:57:50by repeatedly using

01:57:51very tight corsets,

01:57:53but women did not wear them

01:57:54because of fashion.

01:57:56Doctors at the time

01:57:57thought that the corset

01:57:58could help maintain

01:57:59a healthy posture

01:58:00and that it would help

01:58:01to keep the internal organs

01:58:03well aligned.

01:58:04Daphne was not a big fan

01:58:06of corsets herself,

01:58:07but she could sew one.

01:58:09In the Victorian era,

01:58:10the color of the clothes

01:58:11sometimes depended on the laundry.

01:58:13The fact is that white clothes

01:58:15could be soaked

01:58:16and cleaned

01:58:17much more easily

01:58:18than those in bright colors.

01:58:19So the youngest

01:58:20often wore white

01:58:22to easily remove

01:58:23stains if necessary.

01:58:24The more they grew,

01:58:25the more colors became present.

01:58:27Fun fact,

01:58:28pink,

01:58:29as the paler version of red,

01:58:31which was considered

01:58:32a strong and masculine shade,

01:58:34was intended for boys.

01:58:36Girls preferred blue shades.

01:58:39Towards the 1940s,

01:58:41the trend reversed

01:58:43and pink began

01:58:44to be associated with girls.

01:58:45Daphne also often made

01:58:47her pink and blue clothes

01:58:48and earned about

01:58:4910 shillings a week,

01:58:51like many other seamstresses.

01:58:53With this money,

01:58:54Daphne can easily

01:58:55afford a weekly rent

01:58:56of 6 shillings.

01:58:57The rest,

01:58:58she can use to buy food

01:59:00or other essential commodities.

01:59:03With 1 shilling,

01:59:04she can buy enough tea

01:59:05for a week.

01:59:065 loaves of bread

01:59:07cost about 12 pence,

01:59:09which is equivalent to 1 shilling.

01:59:11Good news for vegetarians,

01:59:1312 pence

01:59:14allows you to buy

01:59:14about 8 kilos of vegetables.

01:59:17A bag of coal

01:59:18costs about 1 shilling.

01:59:19You now understand

01:59:20why Daphne and John

01:59:22don't have a fireplace.

01:59:23No one wants to burn

01:59:25literally their money.

01:59:27In addition,

01:59:27for 1 shilling,

01:59:28John can afford

01:59:29a new outfit

01:59:30in case his old clothes

01:59:31couldn't resist

01:59:32this vigorous washing

01:59:34after the fireplace

01:59:35was clogged.

01:59:36To come back to the facilities,

01:59:38what about the toilets?

01:59:40The first public toilets

01:59:41in England

01:59:42were opened in 1851

01:59:44and were even presented

01:59:46at the Universal Exhibition

01:59:47that year.

01:59:48Victorian toilets

01:59:50usually had pipes

01:59:51in the shape of an S.

01:59:53Their purpose

01:59:53was to keep odours at a distance

01:59:56because it was thought

01:59:56that bad odours

01:59:57were dangerous for health,

01:59:59not to mention the disgust

02:00:01they caused.

02:00:02But once again,

02:00:03it was a luxury.

02:00:05Ordinary apartments

02:00:07and rural houses

02:00:08had much less comfortable facilities.

02:00:11Sorry,

02:00:11Daphne prefers

02:00:12not to dwell on the subject.

02:00:15In the evening,

02:00:15there is of course

02:00:16no television,

02:00:17not even electric light.

02:00:19As soon as the sky becomes dark,

02:00:21there is no point

02:00:22in staying awake.

02:00:24In fact,

02:00:24it even costs a nice sum.

02:00:26Candles and oil for lamps

02:00:28are not really cheap.

02:00:30Daphne finished another dress

02:00:32in the afternoon.

02:00:33It is therefore useless

02:00:34to burn a candle.

02:00:35Good night!

02:00:55and playful.

02:00:56Researchers discovered this in 2016,

02:00:59after tickling the stomach of rodents

02:01:02and listening to their little squeaks.

02:01:04Hummingbirds are the only birds

02:01:06we knew

02:01:07that can fly backwards.

02:01:09They do it mainly

02:01:10when they want to get away from the flowers.

02:01:12And here is an animal

02:01:13that is unable to retreat.

02:01:15The kangaroo.

02:01:16They can jump

02:01:17and travel long distances,

02:01:19but the structure

02:01:20of their powerful hind legs

02:01:21and their large tails

02:01:22prevent them from walking backwards.

02:01:26Narwhals are these strange creatures

02:01:28that look like

02:01:29some kind of sea unicorns.

02:01:31This horn on their heads

02:01:33is not a defense.

02:01:35It is a huge tooth

02:01:36that comes out through the upper lip

02:01:38of the male narwhals.

02:01:39This tooth

02:01:40probably plays a role

02:01:41in their nuptial parade.

02:01:43Pink flamingos

02:01:44are not really pink.

02:01:46They are born gray.

02:01:47But during their life,

02:01:48they eat a lot of algae

02:01:50and other foods

02:01:51containing a red-orange pigment

02:01:53that we know

02:01:53as beta-carotene.

02:01:55This pigment is decomposed

02:01:57and ends up

02:01:58in their skin and feathers,

02:02:00which makes them pink.

02:02:01They have to eat

02:02:02a lot of these foods

02:02:03to stay that way.

02:02:05If we humans

02:02:06wanted to change

02:02:07the color of our skin,

02:02:08we would not be able

02:02:09to eat enough

02:02:11beta-carotene foods

02:02:12to become really pink

02:02:14or, in our case,

02:02:16completely orange.

02:02:17The lazy ones are really slow.

02:02:19All the jokes and references

02:02:21to their subject are true.

02:02:23But they are also

02:02:24very skilled swimmers.

02:02:25And they move in the water

02:02:27three to four times

02:02:28faster than on land.

02:02:30They can do the breaststroke

02:02:31just like humans.

02:02:32And it's an important skill

02:02:34for them

02:02:34because they are tropical animals

02:02:36living mainly in the jungle.

02:02:38And these areas are often flooded.

02:02:40Tigers are the largest members

02:02:42of the feline family.

02:02:43And yes,

02:02:44they are also

02:02:45larger than lions.

02:02:47Then,

02:02:47no tiger has the same stripes.

02:02:50Their fur is actually a camouflage,

02:02:52which is useful

02:02:53when they need to find

02:02:54the ideal spot

02:02:55where their prey won't see them.

02:02:57It is interesting to note

02:02:59that their skin is also striped,

02:03:01not just their fur.

02:03:02And their stripes are as unique

02:03:04as our fingerprints.

02:03:07Even if they look

02:03:08rather innocent and funny,

02:03:10you wouldn't want to disturb

02:03:11a ornithologist.

02:03:14These wild animals

02:03:15are among the few mammals

02:03:17capable of poisoning you.

02:03:19They have ergos

02:03:20on the ends of their hind legs

02:03:22that can release venom.

02:03:23They are not societs,

02:03:25powerful enough to be deadly,

02:03:26but the sting can still

02:03:28be very painful

02:03:29and cause inflammation

02:03:30as well as other problems.

02:03:32When a coccinella has to defend itself

02:03:34against any predator,

02:03:36it starts by bleeding from the knees.

02:03:38It's not real blood

02:03:39that comes out of its joints.

02:03:41It's a particular chemical substance

02:03:43that smells very bad

02:03:45and therefore repels predators.

02:03:47They have another mechanism

02:03:49that helps them survive

02:03:51in the pitiful animal kingdom,

02:03:53their specific color.

02:03:55Predators don't really like

02:03:57vivid color combinations

02:03:59such as red, orange and black

02:04:01because they know that colored creatures

02:04:03in this way can have an awful taste.

02:04:05Cockroaches can be extremely noisy

02:04:07in the morning,

02:04:09but they don't go deaf

02:04:11because they don't even hear

02:04:13how loud their cries can be.

02:04:15What protects them

02:04:17are some kind of integrated

02:04:19ski balls.

02:04:21Hens have a similar system

02:04:23that reduces the risk of hearing loss.

02:04:25Not only do they have this protection,

02:04:27but they can also repel

02:04:29their cochlear cells

02:04:31if they are damaged

02:04:33in just a few days.

02:04:35Hibiscus don't really have

02:04:37ocular globes,

02:04:39they have something

02:04:41that looks more like

02:04:43ocular tubes.

02:04:45And they can't move them

02:04:47from left to right

02:04:49as we can do with our eyes.

02:04:51That's why these birds

02:04:53have incredibly flexible necks.

02:04:55They are able to turn their heads

02:04:57at 270 degrees.

02:04:59In comparison,

02:05:01Hibiscus brings fresh blood

02:05:03to the brain

02:05:05if a bird turns its head

02:05:07too quickly

02:05:09and cuts its circulation.

02:05:11Swim straight in front of you.

02:05:13You may remember

02:05:15the way Dory,

02:05:17the blue surgeon fish,

02:05:19sang it in Nemo's world.

02:05:21Dory was not a shark,

02:05:23but it is a message

02:05:25that some species of sharks

02:05:27must take at the foot of the letter.

02:05:29Sharks, whales

02:05:31and other species of fish

02:05:33continue to swim all the time

02:05:35if they don't stop breathing.

02:05:37We don't use our lungs

02:05:39to breathe.

02:05:41And some sharks

02:05:43use a method called

02:05:45buccal pumping.

02:05:47This means they swim

02:05:49with their mouths open.

02:05:51In this way, they allow water

02:05:53to flow through their gills

02:05:55and thus extract oxygen.

02:05:57The most dangerous animal

02:05:59on our planet

02:06:01is not a bear,

02:06:03a shark or a tiger

02:06:05with sharp teeth.

02:06:07It is something much smaller,

02:06:09the mosquito.

02:06:11Not only is it extremely irritating,

02:06:13but it also transmits

02:06:15serious diseases

02:06:17such as yellow fever,

02:06:19malaria or dengue.

02:06:21Every year,

02:06:23hundreds of thousands of people

02:06:25die every year,

02:06:27except termites and ants.

02:06:29Grizzlies

02:06:31are incredibly strong animals

02:06:33with a powerful bite

02:06:35capable of crushing

02:06:37a bowling ball.

02:06:39This is why they are not

02:06:41allowed in the bowling halls.

02:06:43Despite this,

02:06:45they are essentially small eaters.

02:06:47They are strong enough

02:06:49to make their meal

02:06:51everything they encounter,

02:06:53such as fruits, nuts

02:06:55and other berries,

02:06:57or even a little unlucky mouse

02:06:59that would get lost

02:07:01in the predator's mouth.

02:07:03The Desert Taipan

02:07:05is the most venomous snake

02:07:07on the planet.

02:07:09We also know it

02:07:11under the name

02:07:13Doxuranus microlepidotus.

02:07:15It lives in Australia.

02:07:17A single bite

02:07:19secretes enough venom

02:07:21to kill it.

02:07:23It is said that these snakes

02:07:25are the most shy

02:07:27and prefer to worry

02:07:29about their own business.

02:07:31But like other animals,

02:07:33they will attack

02:07:35if they feel threatened

02:07:37or provoked.

02:07:39There is a type of turtle

02:07:41that can stay alive

02:07:43for months under the ice

02:07:45breathing through its back.

02:07:47When it gets colder,

02:07:49the turtles

02:07:51have no choice

02:07:53but to stay

02:07:55in their frozen tanks.

02:07:57As the ice limits

02:07:59their access to the air,

02:08:01they directly extract

02:08:03the oxygen from the water

02:08:05and breathe through their backs.

02:08:07Yes, I admit

02:08:09it would be very practical.

02:08:11It is well known

02:08:13that crows

02:08:15are incredibly intelligent animals.

02:08:17They are very in tune

02:08:19with their feelings

02:08:21as well as with the emotions

02:08:23of their companions.

02:08:25If a crow in the group

02:08:27feels moody,

02:08:29it is likely that it also

02:08:31attracts others.

02:08:33When it sees a bird

02:08:35that does not like

02:08:37certain food

02:08:39and expresses it

02:08:41very vividly,

02:08:43it also loses

02:08:45its attention.

02:08:47The crow

02:08:49is one of the noisiest

02:08:51animals in the world,

02:08:53even if it is tiny,

02:08:55only 1.9 meters long.

02:08:57When it detects a prey,

02:08:59it opens its big claw

02:09:01that can reach

02:09:03up to half the length

02:09:05of its own body

02:09:07and let it enter

02:09:09a little from above.

02:09:11Then it closes the claw

02:09:13and when the bubbles burst,

02:09:15they produce a surprisingly

02:09:17loud detonation

02:09:19of more than 210 decibels.

02:09:21Crocodiles are even more

02:09:23frightening than we thought

02:09:25because many of them

02:09:27can gallop like goats.

02:09:29They probably inherited

02:09:31this ability from their

02:09:33ancient ancestors.

02:09:35Crocodileomorphs,

02:09:37which were as clumsy

02:09:39as cats,

02:09:41the smallest crocodiles

02:09:43gallop most often when

02:09:45something pursues them.

02:09:47But caimans and alligators

02:09:49obviously do not need

02:09:51to use this skill.

02:09:53It is you who are most likely

02:09:55to take your legs

02:09:57when you see them.

02:09:59You just sat down

02:10:01to eat in your favorite restaurant.

02:10:03The waiter comes to take

02:10:05your order of drinks.

02:10:07You wanted soda all day,

02:10:09but he says,

02:10:11we only have Pepsi.

02:10:13Can you count the number

02:10:15of times it happened to you?

02:10:17Even when you travel abroad,

02:10:19it's either Coke or Pepsi

02:10:21and you end up having to

02:10:23choose your side.

02:10:25Let's dig a little into this rivalry.

02:10:27Is one of the two objectively

02:10:29better than the other?

02:10:31First criterion, variety.

02:10:33Both drinks are pretty good

02:10:35in this field.

02:10:37With Pepsi, you can order

02:10:39flavors as original as lemon,

02:10:41lime, caramel and even

02:10:43some spicy flavors.

02:10:45The next criterion is the taste.

02:10:47It's something very personal,

02:10:49so there is no absolute truth.

02:10:51But everyone has his favorite.

02:10:53The Coca-Cola recipe

02:10:55is a secret that has been

02:10:57jealously kept since 1891

02:10:59when John Pemberton,

02:11:01the inventor of the drink,

02:11:03sold his recipe.

02:11:05It's still the recipe

02:11:07we know and love today.

02:11:09The sweet taste of Pepsi

02:11:11was developed by Caleb Bradham.

02:11:13Some time later,

02:11:15Charles Goose bought

02:11:17the company in bankruptcy.

02:11:19This man also owned a candy

02:11:21company called Loft.

02:11:23Can this explain why

02:11:25Pepsi's recipe is sweeter

02:11:27than Coca-Cola's?

02:11:29Now, you just woke up.

02:11:31You ordered a pizza the day before

02:11:33to eat the leftovers for your breakfast.

02:11:35You open the fridge and oh!

02:11:37You are faced with a difficult choice.

02:11:39Cold pizza or cold pasta?

02:11:41Why do these two dishes

02:11:43still taste so good when they are cold?

02:11:45It's a matter of chemical composition.

02:11:47According to pasta experts,

02:11:49spaghetti tastes even better

02:11:51the next day thanks to an element

02:11:53called starch.

02:11:55It is mainly found in cereals

02:11:57and potatoes.

02:11:59To put it simply, the ingredients

02:12:01take more time to mix

02:12:03when they spend the night in the fridge.

02:12:05Starch absorbs fat, sauce

02:12:07and seasoning during the night.

02:12:09It sucks in all the flavor

02:12:11and makes the flavor much richer.

02:12:13This is just as good for pizza

02:12:15as it is for pasta.

02:12:17So it's not a coincidence

02:12:19that some people often order this kind of food

02:12:21just to have leftovers to enjoy

02:12:23the next morning.

02:12:25Still on the theme of pizza,

02:12:27let's settle the pineapple issue

02:12:29It is true that it is a red line

02:12:31that many of us refuse to cross.

02:12:33On the one hand, some say that

02:12:35bees do not have their place on a pizza.

02:12:37Wait, what?

02:12:39In case you don't know,

02:12:41pineapples are bees,

02:12:43or more precisely, a group of bees

02:12:45that have merged together.

02:12:47On the other hand, there are the unconditional

02:12:49of Hawaiian pizza.

02:12:51Those will try to convince you

02:12:53that pineapple is delicious

02:12:55when it is mixed with tomato sauce.

02:12:57What do you have to say about this?

02:12:59Are you for or against?

02:13:01By the way, have you ever tried

02:13:03pineapple in a hamburger?

02:13:05Yes, they have also conquered hamburgers.

02:13:07Some amateurs claim that pineapple

02:13:09plays the same role as pickles.

02:13:11It brings this sweet and sour flavor

02:13:13that your burger needs.

02:13:15Two twin sisters

02:13:17are never really identical,

02:13:19except when it comes to Bar Twix.

02:13:21Have you already chosen your side?

02:13:23Do you eat the Twix on the left

02:13:25or on the right?

02:13:27Does it make a difference

02:13:29or is it just a marketing trick?

02:13:31If you bought Twix recently,

02:13:33you have probably been confronted

02:13:35with three options.

02:13:37An ordinary package,

02:13:39a package supposed to contain

02:13:41two bars on the left,

02:13:43and another supposed to contain

02:13:45two bars on the right.

02:13:47As you may know, Twix come in pairs.

02:13:49But in 2012, the company Mars,

02:13:51which makes the Twix,

02:13:53started to claim that the bars

02:13:55were not real twins.

02:13:57Thanks to very humorous ads,

02:13:59Mars made people believe

02:14:01that the production process

02:14:03of each bar was different.

02:14:05The story goes that the inventors

02:14:07of Twix, the brothers Earl and Simus,

02:14:09one day reached a breaking point.

02:14:11They did not agree on the technique

02:14:13of pouring chocolate and the consistency

02:14:15of the caramel.

02:14:17So each brother started

02:14:19to found his own company.

02:14:21Twix, on the other hand,

02:14:23has a crunchy biscuit

02:14:25sprinkled with caramel

02:14:27and coated with chocolate.

02:14:29While Twix, on the other hand,

02:14:31has a crispy biscuit

02:14:33and a creamy base of caramel

02:14:35wrapped in chocolate.

02:14:37Which is a bit the same,

02:14:39by the way.

02:14:41But anyway,

02:14:43some enthusiastic fans

02:14:45even checked the facts

02:14:47to see if there was a real difference

02:14:49between Twix and Twix.

02:14:51The left bars obtained

02:14:53an average of 72.3 decibels

02:14:55of crunchiness,

02:14:57while the right ones

02:14:59had an average of 69.6 decibels.

02:15:01Does this mean that the left bar

02:15:03is better? It's up to you to judge.

02:15:05Fans think it could be due

02:15:07to the packaging or storage

02:15:09of the Twix bars.

02:15:11They suggest that it is less

02:15:13of a left-right difference

02:15:15than at the bottom.

02:15:17In the United States,

02:15:19the main debate is

02:15:21peanut butter on top

02:15:23or under the jam.

02:15:25If you are an amateur,

02:15:27you had to develop a preference.

02:15:29Unless you consider it

02:15:31as a sacrilege

02:15:33to mix peanut butter

02:15:35and jam.

02:15:37Some people have well-defined

02:15:39opinions on how to make

02:15:41the perfect peanut butter jam sandwich.

02:15:43Some say that peanut butter

02:15:45is the perfect base for jam,

02:15:47while others say that jam

02:15:49should be spread first

02:15:51because it is thinner and spreads more easily.

02:15:53So, which side are you on?

02:15:55Now, are you more

02:15:57a taco or a falafel?

02:15:59You may wonder if it's really comparable.

02:16:01These two types of sandwich

02:16:03are delicious, but serve

02:16:05completely different goals.

02:16:07Tacos are a Mexican dish

02:16:09made of a fried tortilla

02:16:11stuffed with beans, salad

02:16:13or any other meat of your choice.

02:16:15Falafel is a dish from the Middle East

02:16:17which consists mainly of

02:16:19chickpea or ground beef patties

02:16:21perfectly seasoned,

02:16:23stuffed with pita bread

02:16:25with many different fillings and sauces.

02:16:27We certainly did not go through

02:16:29all the food debates,

02:16:31but it certainly made you drool,

02:16:33didn't it?

02:16:35And if you don't know what to choose,

02:16:37opt for a falafel taco.

02:16:39Yes, it really exists!

02:16:41Apparently, some people

02:16:43are convinced that coffee is not a drink

02:16:45but rather a soup.

02:16:47According to some supporters of this theory,

02:16:49coffee is actually a broth,

02:16:51because the coffee beans are finely ground

02:16:53and then infused in water.

02:16:55This process creates a non-thick liquid

02:16:57generally recognized as a broth.

02:16:59This theory has its detractors, of course.

02:17:01They claim that coffee

02:17:03does not look at all like a broth,

02:17:05because it should imply

02:17:07that the liquid has a certain nutritional value.

02:17:09However,

02:17:11coffee is simply coffee.

02:17:13It is supposed to taste good

02:17:15and give you energy,

02:17:17but it will not fill your stomach.

02:17:19Tell us in the comments below

02:17:21what is your preference

02:17:23for each of these food debates.

02:17:25Poor Pierre,

02:17:27he is so afraid of insects

02:17:29that his dearest wish would be

02:17:31to find a place on earth

02:17:33where he would not have to deal with them.

02:17:35After years of research and travel,

02:17:37he found the ideal place,

02:17:39Antarctica.

02:17:41Pierre moved there, convinced

02:17:43that insects do not survive the cold.

02:17:45He did not know that insects live

02:17:47on each continent of this planet.

02:17:49Well, not quite.

02:17:51He was right about Antarctica.

02:17:53There are not many insects there.

02:17:55In fact,

02:17:57there is only one species of insect

02:17:59that lives there.

02:18:01It is a wingless fly

02:18:03called Belgica antartica.

02:18:05It is a very small insect,

02:18:07but it is the largest

02:18:09terrestrial insect in Antarctica.

02:18:11Ok, we understand

02:18:13that there is no place on earth

02:18:15without insects.

02:18:17Well, it is not entirely true either.

02:18:19You will have to learn to swim,

02:18:21because the only place on earth

02:18:23that is not inhabited by insects

02:18:25is the surface covered by the ocean.

02:18:27But why do insects

02:18:29avoid this area so much?

02:18:31No one has found an explanation.

02:18:33But this may be due

02:18:35to the lack of vegetation in the ocean.

02:18:37Indeed, insects need plants

02:18:39to feed and shelter.

02:18:41Insects are present everywhere,

02:18:43and they have ears everywhere.

02:18:45They could create the most efficient

02:18:47network of spying in the world.

02:18:49However, their ears are not always

02:18:51on their heads.

02:18:53Some insects have ears on their wings,

02:18:55some on their legs,

02:18:57others on the abdomen

02:18:59or even on the neck.

02:19:01But some of them have families.

02:19:03Like the Passals, for example.

02:19:05They create family structures

02:19:07where the two parents

02:19:09raise their children.

02:19:11They also have a good

02:19:13vocabulary,

02:19:15and they communicate by whistling.

02:19:17If an insect falls

02:19:19from a certain height,

02:19:21does it hurt?

02:19:23It's a little more complex than that,

02:19:25but let's take ants as an example.

02:19:27They don't hurt

02:19:29when they fall,

02:19:31because they are extremely small.

02:19:33Many insects can technically fall

02:19:35from very high without hurting themselves.

02:19:37It takes a lot of math

02:19:39and physics

02:19:41that the insects themselves

02:19:43don't have time to study,

02:19:45to explain all this.

02:19:47To simplify, they are so light

02:19:49that there is no impact

02:19:51with the surface on which they fall.

02:19:53When they fall,

02:19:55they don't accumulate speed,

02:19:57but their weight creates a lot of friction in the air,

02:19:59and the ant ends up

02:20:01slowing down at the end of the fall.

02:20:05Speaking of ants,

02:20:07I already talked about it, right?

02:20:09There are on average

02:20:11a billion of them on Earth.

02:20:13That's about 1.4 million ants

02:20:15per human,

02:20:17for a population of 7.3 billion inhabitants.

02:20:21If we calculate it like that,

02:20:23it's more their planet than ours, right?

02:20:25It's hard to imagine a fruit fly

02:20:27with an astronaut helmet.

02:20:29But these are the first living creatures

02:20:31sent into space.

02:20:33In 1947,

02:20:35these flies said goodbye to Earth,

02:20:37and they were sent into space

02:20:39in a V2 rocket

02:20:41that reached an altitude of 110 km

02:20:43in less than 200 seconds.

02:20:45They landed on Earth with a parachute.

02:20:47Not all insects are

02:20:49so lucky.

02:20:51For example, caterpillars have 12 eyes,

02:20:53but they are almost completely blind.

02:20:55Their little eyes only distinguish

02:20:57light and darkness.

02:20:59They don't have a precise picture

02:21:01of what is in front of them.

02:21:03And no, glasses

02:21:05would make no difference, unfortunately.

02:21:07Some insects are very active,

02:21:09let's say...

02:21:11sentimentally.

02:21:13Plecopters, for example,

02:21:15pump to attract young ladies.

02:21:17Did you know that butterflies

02:21:19taste their environment with their paws?

02:21:21That's right, you got it right.

02:21:23They have taste sensors in their paws

02:21:25to help them find food.

02:21:29They land on a caterpillar,

02:21:31and the drop.

02:21:33If they understand that it is a plant

02:21:35that their caterpillars can eat,

02:21:37they lay their eggs there.

02:21:39But how do they eat?

02:21:41Since they can neither bite nor chew.

02:21:43They use their long tongue,

02:21:45which looks more like a tube

02:21:47called proboscis.

02:21:49It's a kind of straw

02:21:51that helps butterflies swallow liquids

02:21:53like nectar, for example.

02:21:55The ancestors of these fantastic beings

02:21:57lived on this planet

02:21:59long before the dinosaurs.

02:22:01According to fossil chronicles,

02:22:03sauterelles appeared on Earth

02:22:05more than 300 million years ago.

02:22:09Have you ever heard of the insect

02:22:11Phanderock?

02:22:13Indeed, termites like this type of sound.

02:22:15They nibble the wood

02:22:17to understand what type of wood

02:22:19is present around them.

02:22:21They use vibrations.

02:22:23Why?

02:22:25Because they allow them to find

02:22:27the best source of food.

02:22:29If they are exposed to heavy metal

02:22:31or rock,

02:22:33they will nibble the wood faster.

02:22:35Do they slow down

02:22:37if they listen to Bach or Brahms?

02:22:39Or do they just fall asleep?

02:22:41Here is an insect

02:22:43It's the boss of disguises.

02:22:45It looks like a leaf.

02:22:47These insects have developed

02:22:49this ability to camouflage

02:22:51so that predators

02:22:53can't spot them.

02:22:55They can also swing

02:22:57like leaves shaken by the wind.

02:23:01Nature has its own meteorologists,

02:23:03the crickets.

02:23:05Indeed, they work

02:23:07like thermometers.

02:23:09You can calculate the external temperature

02:23:11manually by counting the stridulations

02:23:13of a cricket per minute,

02:23:15then dividing them by 4

02:23:17and subtracting 19.

02:23:19You will thus obtain

02:23:21an estimate of the temperature

02:23:23in degrees Celsius.

02:23:25Crickets also produce

02:23:27a unique song that they use

02:23:29to attract their partners

02:23:31and defend their territory.

02:23:33Yes, it's a music that attracts

02:23:35and repels at the same time.

02:23:37You should use coccinellas

02:23:39for your free gardening.

02:23:41They feed on insect-parasite plants,

02:23:43among other things.

02:23:45They can keep flies away from fruits

02:23:47as well as aquariums.

02:23:49In a lifetime,

02:23:51more or less a year,

02:23:53a coccinella can eat up to 5000 insects.

02:23:57Here are some incredible data

02:23:59on our friends the bees.

02:24:01Their wings can beat

02:24:03up to 190 times per second.

02:24:05I'm doing the math.

02:24:07That's 11,400 times per minute.

02:24:09That's sport!

02:24:11They need to be in shape

02:24:13because a single colony of

02:24:15honeybees can produce

02:24:17up to 100 kg of honey per year.

02:24:19That's 220 pots.

02:24:23It's the natural equivalent of a factory.

02:24:25But you should teach bees

02:24:27how to produce honey.

02:24:29It's not in their natural instinct.

02:24:31Another fascinating information

02:24:33about the bees' lives

02:24:35The temperature inside a hive

02:24:37is always around 34°C,

02:24:39regardless of the outside temperature.

02:24:41Bees are very strong

02:24:43to isolate their hives.

02:24:45They also have different stomachs

02:24:47to eat and accumulate honey.

02:24:49They are multitasking.

02:24:55OK, no panic.

02:24:57But I think you'll like

02:24:59some of this information

02:25:01about spiders.

02:25:03They help us control parasites

02:25:05in our cultures.

02:25:07So we should

02:25:09thank them.

02:25:11They also have

02:25:13an incredible vision.

02:25:15They see light spectra

02:25:17that we don't see,

02:25:19like UVA and UVB lights.

02:25:21They also have other superpowers.

02:25:23For example, a spider's wire

02:25:25is 5 times stronger than a steel wire.

02:25:27If it was the same thickness, of course.

02:25:29Some researchers think

02:25:31that if spiders were human-sized,

02:25:33and let's hope that never happens,

02:25:35their wire could stop objects

02:25:37as big as airplanes.

02:25:39And this spider's silk

02:25:41is a liquid that hardens

02:25:43in contact with the air.

02:25:45They are also quite rusty

02:25:47and have gradually acquired

02:25:49more resemblance to ants.

02:25:51Why? To be less visible

02:25:53to predators, but also

02:25:55to better hunt ants.

02:25:57Spiders don't have wings,

02:25:59which is 50 times their size.

02:26:01Well, I still have chicken skin

02:26:03when I think of spiders.

02:26:05What about you?

02:26:07The world's largest sand castle

02:26:09is located in Denmark.

02:26:11It is more than 21 meters high.

02:26:13The 30 sculptors who created it

02:26:15used more than 5,000 tons of sand.

02:26:17To make it more durable,

02:26:19they added 10% clay

02:26:21and a layer of glue.

02:26:23They built it to resist

02:26:25long and stormy winters.

02:26:29You can really spend the night

02:26:31inside a giant potato.

02:26:33The next time you want to

02:26:35rest in a rather unique way,

02:26:37you can book a bed

02:26:39inside an 8.5-meter-long

02:26:41and 3.7-meter-wide potato.

02:26:43At least that's what this

02:26:45original structure, made of

02:26:47concrete, steel and plaster,

02:26:49looks like a potato.

02:26:53The teenagers of the other decades

02:26:55are different from today's high school students.

02:26:57At first glance,

02:26:59they look much older, don't you think?

02:27:03But it's simply because

02:27:05they have a different style.

02:27:07As they grew up,

02:27:09they kept buying the same clothes

02:27:11they thought were cool.

02:27:13Today, we associate this same style

02:27:15with people in their 50s or 60s.

02:27:17Thus, when we see pictures

02:27:19of these people in their teens,

02:27:21we get the impression that they have aged.

02:27:23In reality,

02:27:25they look like today's teenagers.

02:27:27The same thing will happen

02:27:29with today's teenagers.

02:27:31They will keep buying the clothes

02:27:33they think are cool when they get older.

02:27:35That's why future generations

02:27:37will associate their clothing style

02:27:39with the elderly.

02:27:41Jaguars, black caimans,

02:27:43sloths, giant tattoos...

02:27:45There are many different animals

02:27:47you can find in the Amazon rainforest.

02:27:49But what was that just now?

02:27:51Let's rewind a bit.

02:27:53In the middle,

02:27:55you can find a humpback whale.

02:27:57It's rare to see one,

02:27:59even in the middle of the ocean.

02:28:01But it's really amazing to find one

02:28:03in the middle of the Amazon.

02:28:05And that's what happened in 2019

02:28:07when people found a lifeless humpback whale.

02:28:09The animal probably died

02:28:11in the mouth of the Amazon river

02:28:13and ended up on the mainland

02:28:15when the tides receded.

02:28:17Elephants have huge ears.

02:28:19And normally,

02:28:21they tend to hear sounds

02:28:23from the front and the back.

02:28:25But sometimes,

02:28:27they can hear distant sounds

02:28:29with their paws.

02:28:31When they detect something distant,

02:28:33the elephants freeze and lean forward.

02:28:35They transfer their weight

02:28:37on their front paws

02:28:39and can even lift one of their feet.

02:28:41People often think

02:28:43that apple pie is from America.

02:28:45But no.

02:28:47Apples are actually from Asia.

02:28:49The recipe for apple pie

02:28:51was invented in England.

02:28:53When a material

02:28:55is exposed to the sun,

02:28:57where does the color go?

02:28:59The color of a given material

02:29:01comes from the part of molecules

02:29:03called chromophores.

02:29:05They absorb photons

02:29:07at particular wavelengths.

02:29:09The photon is the basic particle

02:29:11of light.

02:29:13Some photons that are not absorbed

02:29:15are re-emitted,

02:29:17which can damage

02:29:19the chromophores.

02:29:21That's why they won't be able

02:29:23to emit photons

02:29:25at certain wavelengths.

02:29:27Red materials are the ones

02:29:29that stick the most to sunlight.

02:29:31Their chromophores emit

02:29:33red light in a way

02:29:35that absorbs photons

02:29:37at other wavelengths.

02:29:39You prepare a meal,

02:29:41you chop vegetables,

02:29:43and, oh no, tears flow.

02:29:45Because breaking the skin

02:29:47releases enzymes and sulfenic acid.

02:29:49When they combine,

02:29:51they produce a gas

02:29:53that spreads in the air

02:29:55and irritates your eyes.

02:29:57This causes tear glands

02:29:59to produce tears

02:30:01to evacuate this irritating acid.

02:30:03Your brain can't perform

02:30:05two things at the same time

02:30:07that require a high-level brain function.

02:30:09And no, you can't really be multitasking.

02:30:11We can't consider subaltern functions

02:30:13as multitasking.

02:30:15It's an action you have to think about.

02:30:17So, what you consider

02:30:19multitasking is

02:30:21quickly switching from one task to another.

02:30:25Try moving your feet and hands

02:30:27in opposite directions.

02:30:29Sit on a chair and turn your left leg

02:30:31clockwise,

02:30:33drawing an 8 with your left hand.

02:30:35Or do the same thing

02:30:37with your right hand and leg.

02:30:39It looks like your leg changed direction, doesn't it?

02:30:41That's what happens to almost everyone.

02:30:43If you turn your leg

02:30:45counterclockwise,

02:30:47the same thing will happen.

02:30:49When you're driving

02:30:51at a very fast speed,

02:30:53you can feel this strange force

02:30:55and it looks like it wants to make you fall.

02:30:57Our planet is like a huge carousel

02:30:59that spins in space

02:31:01at about 1,609 km per hour.

02:31:03But we don't feel this rotational force

02:31:05because another force

02:31:07acts on our planet and on us.

02:31:09It holds us firmly to the ground

02:31:11about a thousand times stronger

02:31:13than our planet spins

02:31:15trying to catapult us into space.

02:31:19Toothpaste contains edulcorants

02:31:21because it's made of detergents

02:31:23that create foam when you brush your teeth

02:31:25and it needs something

02:31:27to mask the awful taste of soap they bring.

02:31:29Of course, sugar is excluded,

02:31:31but there are other edulcorants,

02:31:33xylitol or sorbitol,

02:31:35which do a good job

02:31:37removing the detergents.

02:31:39These chemical edulcorants attract water.

02:31:41They keep the water molecules

02:31:43locked in the toothpaste

02:31:45so that they don't dry out.

02:31:47Have you ever noticed

02:31:49that you're often less hungry

02:31:51when it's hot outside?

02:31:53All the metabolic processes

02:31:55that take place in our body,

02:31:57including digestion,

02:31:59produce heat.

02:32:01Of the 1,000 calories you eat,

02:32:03your body converts only 250

02:32:05into lost heat.

02:32:07When it's hot outside,

02:32:09your body works hard to keep you from overheating.

02:32:11So it doesn't really need

02:32:13the extra heat it generates

02:32:15by digesting the big meal you ate.

02:32:17That's why your body reduces your appetite

02:32:19for a while and uses more energy

02:32:21in the fat reserves

02:32:23it has previously stored.

02:32:25Sometimes dreams can seem brighter

02:32:27when you don't sleep in your own bed.

02:32:29When you spend the night at the hotel

02:32:31or somewhere else you're not familiar with,

02:32:33you experience what scientists call

02:32:35the first night effect.

02:32:37One of these studies

02:32:39revealed that the left side of our brain

02:32:41slept less well than the right side

02:32:43during the first night spent

02:32:45in a new environment.

02:32:47This is probably due to an evolutionary mechanism

02:32:49that makes us watch out

02:32:51for predators and potential dangers.

02:32:53There is probably no monster

02:32:55under the bed in your hotel room,

02:32:57but you wouldn't be so sure

02:32:59if you had lived thousands of years ago.

02:33:01You are probably more likely

02:33:03to wake up during your first night

02:33:05in your new environment.

02:33:07When you wake up often,

02:33:09you remember your dreams much better.

02:33:11That's why they can seem more lively

02:33:13in such situations.

02:33:15You're at work,

02:33:17you've just had lunch

02:33:19and you're about to finish

02:33:21the last task of the day,

02:33:23but you can't make it.

02:33:25You have such a drop in energy

02:33:27that you want to lie down

02:33:29but you can't because

02:33:31you've had a glucose-rich meal,

02:33:33a lack of sleep the day before

02:33:35or a certain dehydration.

02:33:37And there is another possible reason.

02:33:39A small region of your brain,

02:33:41the suprachiasmatic nucleus,

02:33:43or NSC,

02:33:45controls your internal biological clock,

02:33:47also called the circadian rhythm.

02:33:49This part sends signals to your body

02:33:51to release melatonin,

02:33:53a hormone inducing drowsiness.

02:33:55It makes you want to sleep

02:33:57but you can't because

02:33:59you don't have enough sleep.

02:34:01You also go through a reduced version

02:34:03of this process between 14 and 16 hours.

02:34:05We still don't know why,

02:34:07but some researchers think

02:34:09it could be due to the fact

02:34:11that our circadian rhythm

02:34:13has a primary cycle of 24 hours

02:34:15and a cycle of 12 hours.

02:34:17You may feel like the best ideas

02:34:19come to your mind

02:34:21when you try to fall asleep.

02:34:23The transition between

02:34:25sleep and creativity

02:34:27could be linked.

02:34:29Marie Shelley said

02:34:31that the idea of her popular novel

02:34:33Frankenstein came to her

02:34:35during the awake dream phase.

02:34:37Salvador Dali, a famous artist,

02:34:39called this phase

02:34:41the sum with a key.

02:34:43In this state,

02:34:45your mind feels free to wander

02:34:47and has no phone,

02:34:49no one or anything else

02:34:51that can disturb it.

02:34:53If you fall asleep

02:34:55right after entering this state,

02:34:57you will probably forget

02:34:59most of your original ideas.

02:35:01So keep a piece of paper

02:35:03and a pen near your bed,

02:35:05just in case.

02:35:0736.7°C is a temperature

02:35:09that seems hot

02:35:11even if the human body

02:35:13is at the same temperature.

02:35:15In fact, it is the average temperature

02:35:17of our nucleus.

02:35:19Our skin has a temperature

02:35:21but our fingers, our toes

02:35:23and our face can be much colder.

02:35:25The receptors of our skin

02:35:27react to differences

02:35:29and temperature changes.

02:35:31If you touch your naked belly

02:35:33with your hand,

02:35:35it will record heat

02:35:37but your belly will feel cold

02:35:39even if both have the temperature

02:35:41of the skin.

02:35:43Similarly, if you put a finger

02:35:45in your mouth,

02:35:47the interior will seem

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