Les films nous ont fait croire des choses incroyables sur l'espace ! Pour commencer, en réalité, vous ne pouvez pas simplement exploser dans l'espace, comme ils le montrent dans les films - il n'y a pas d'air pour provoquer ce genre d'explosion. Et ces batailles de vaisseaux spatiaux super bruyantes ? Elles seraient en fait silencieuses, car le son ne peut pas se propager dans le vide de l'espace. Il y a aussi l'idée que les champs d'astéroïdes ressemblent à un parcours d'obstacles ; en réalité, ils sont tellement espacés que vous ne percuteriez probablement jamais quoi que ce soit. Et qu'en est-il des trous noirs semblables à du sable mouvant qui aspirent tout ? Ce sont plutôt des tourbillons cosmiques qui n'attirent que les objets très proches d'eux. Oh, et si vous essayiez de planter un drapeau sur la Lune comme dans les films, il ne flotterait pas - il n'y a pas de vent pour le faire onduler ! Animation créée par Sympa. ---------------------------------------------------------------------------------------- Musique par Epidemic Sound https://www.epidemicsound.com Pour ne rien perdre de Sympa, abonnez-vous!: https://goo.gl/6E4Xna ---------------------------------------------------------------------------------------- Nos réseaux sociaux : Facebook: https://www.facebook.com/sympasympacom/ Instagram: https://www.instagram.com/sympa.officiel/ Stock de fichiers (photos, vidéos et autres): https://www.depositphotos.com https://www.shutterstock.com https://www.eastnews.ru ---------------------------------------------------------------------------------------- Si tu en veux encore plus, fais un tour ici: http://sympa-sympa.com
Category
😹
FunTranscript
00:00Many science fiction movies will make you believe that everything that happens in space is accompanied by a kind of sound effect.
00:07But it is absolutely false. In space, no one will hear you scream. There is no air. The void is almost perfect.
00:15And the sound waves do not spread in the void. They cannot reach your eardrums and make them vibrate.
00:21Nor send signals to your brain. But it's a good thing. Especially for astronauts out in space.
00:28Without the silence that reigns there, they would be completely deafened by the sound of solar storms.
00:34Is there anything more impressive than a gigantic explosion in space? Whether it is scientifically possible or not, that's another question.
00:42On our planet, explosions are what they are because of the air and gravity.
00:47You see, the air is a western agent. And the pressure makes everything fly in a spectacular way, and then collapse.
00:54But this process is very different in space. And it's even more formidable.
00:59If an explosion occurred in space, there would still be a little fire despite the lack of air.
01:05Because certain types of fuel can take the place of western agents.
01:09But it would not be the fire you are used to. This fire would look like an expanding ball of light.
01:16And the process would apparently be endless because of the microgravity and the lack of air resistance.
01:22Space shuttles in the vicinity would be in great danger.
01:26Because splinters would fly in all directions until something stopped them.
01:31All comets have beautiful and long tails. Here is another well-received idea.
01:36In reality, comets are celestial bodies very difficult to spot.
01:40They usually spend long periods far from the stars.
01:44There, in the darkness of space, they are rather inactive and completely frozen.
01:50The tails of comets only form when they approach a star.
01:54It is then that they begin to warm up.
01:57This process allows them to surround themselves with a kind of cloudy atmosphere, or hair, and to have a tail.
02:04The tail always points to the opposite of the star that influences the comet.
02:08The reason is that the tail is blown by radiation and solar winds.
02:13This is why the tail can often be in front of the comet, and not behind.
02:18The internal and external planets of the solar system are separated by an asteroid belt.
02:24A ring made up of various debris and space objects orbiting the sun.
02:29When they shoot a film in space, filmmakers often use this region as a setting.
02:34In general, they show us the asteroid belt as an extremely crowded place.
02:39With compact clouds of gigantic rocks through which the pilots must maneuver skillfully.
02:45In reality, if you took a look at this area when your ship crossed it,
02:49it would be a bit like when you look at the sky from Earth.
02:53Because in truth, the distances are immense in space.
02:57If you decided to cross this asteroid belt, you would have very little chance of coming across a space object.
03:03Asteroids are really very far from each other.
03:06Black holes are huge and frightening cosmic vacuum cleaners.
03:12But in reality, they look more like fly traps.
03:16They do not actively seek things they could devour.
03:20Instead, they wait, passively.
03:23It is only when a star, or any other object, approaches too close, that a black hole takes action.
03:30And even so, only the space bodies that cross a certain limit are torn apart.
03:37In fact, black holes are no different from any other celestial body.
03:42Their attraction is directly proportional to their mass.
03:46They only swallow what their size allows them to swallow.
03:49If our sun, for one reason or another, were to be replaced by a black hole,
03:54nothing would change for the Earth or any other planet in the solar system.
03:59From the point of view of gravity, of course.
04:02We often use lasers in space battles in the cinema.
04:06But if you watched such a fight up close, you would probably be disappointed.
04:11In fact, it would not look at all like what we see in the movies.
04:15A laser beam is a concentrated discharge of energy.
04:18And we could actually use it for many purposes during a fight.
04:22But a real laser beam would be totally invisible in space,
04:26since there would be no particles to diffuse the light and make it bright red, green or other.
04:32A human would be torn to pieces if he found himself in space without a special suit.
04:38Well, contrary to popular belief,
04:41removing his suit during an extravehicular exit would not be as dramatic as what is often illustrated in the movies.
04:49The timid astronaut would simply lose consciousness after 15 seconds due to lack of oxygen.
04:55But only if he exhaled as much air as possible.
04:59Otherwise, it is the oxygen itself that would damage his lungs from the inside, tearing them apart.
05:05After that, without the protection of the suit, the pressure inside his body would drop.
05:11And that would cause even more serious problems.
05:14So, although our astronaut would not explode in a spectacular way,
05:18he would very quickly have big, big troubles.
05:21People often believe that in space, we experience the absence of gravity.
05:25It is said that astronauts are in weightlessness in the International Space Station.
05:30But this is not entirely true.
05:32Gravity is one of the most important forces in the universe.
05:36Thanks to it, the Moon orbits around the Earth.
05:39And the Sun will not wander off our Milky Way.
05:43Astronauts from the International Space Station can feel the effects of gravity.
05:48But we are rather talking about microgravity.
05:51The gravity in the space station is only 10% lower than the gravity on the surface of the Earth.
05:58But astronauts are constantly in free fall.
06:01The spaceship, the people inside, and all the objects on board keep falling forward.
06:07Not down, but around our planet, following a specific orbit.
06:12And as everything falls at the same time, the crew and the objects inside seem to float.
06:17This is why astronauts are able to move objects weighing hundreds of kilos from the tip of their fingers.
06:23So, calling microgravity absenteeism is not entirely accurate.
06:28A light year translates a quantity of time, doesn't it?
06:31Not really.
06:32Light years actually measure distances.
06:35The definition of the NASA of a light year is as follows.
06:39The total distance that a beam of light, moving in a straight line, travels in a year.
06:45And since light travels at a speed of about 300,000 km per second,
06:50a light year is equivalent to about 9,460 and 11 billion kilometers.
06:55One might think that the sun is always on fire.
06:58This is at least what the photographs and films seem to show us.
07:02But in reality, our star is a gigantic gas ball.
07:06Permanent nuclear reactions in its core burn it.
07:10Every second, hundreds of millions of tons of hydrogen are converted into almost as much helium.
07:16During this process, huge amounts of energy are released in the form of gamma rays.
07:22Then, these rays turn into light.
07:25In other words, the sun actually emits dazzling light and incredible heat.
07:31But it is not really on fire, because there is no oxygen in the process.
07:36The speed of light is considered the ultimate barrier when it comes to space travel.
07:42And we often think that it is impassable.
07:45There are many theories about what it could be to reach this speed,
07:49but no equation evokes the possibility of surpassing it.
07:53And yet, we know that there is at least one thing in the universe that is faster than the speed of light.
07:59It is the rate of its expansion.
08:01Yes, the universe expands faster than the speed of light.
08:05And this disconcerts astronomers as much as simple physicists.
08:10But this limit applies to objects moving in space.
08:14Not to the universe itself, which expands independently.
08:18At present, this is not something that scientists understand well.
08:22The rate of expansion of the universe is also proportional to the distance of an object.
08:28The further away it is from us, the faster it moves away.
08:32But even if we do not grasp its mechanics yet, we have our proof.
08:37Even if it remains theoretical for the moment.
08:40That some particles could be able to move faster than the speed of light.
08:46Some scientists think that there could be certain things in space capable of defying this limit.
08:52We just have to find them.