Les scientifiques ont exploré l'idée que le temps pourrait ne pas être aussi réel que nous le pensons - il pourrait simplement être quelque chose que nos cerveaux ont inventé pour donner un sens au monde. La façon dont nous mesurons le temps, comme les secondes, les minutes et les heures, est basée sur la manière dont la Terre se déplace autour du soleil, mais ce n’est qu’un système conçu par l’homme. Certains physiciens soutiennent que, dans le grand schéma de l'univers, le passé, le présent et le futur existent tous en même temps, et ce que nous vivons comme "maintenant" n’est que notre perspective. Cette idée provient de théories comme la relativité d’Einstein, où le temps peut s’étirer ou se contracter en fonction de la vitesse ou de la gravité. Sans humains pour le suivre, le "temps" pourrait même ne pas exister de la manière dont nous le comprenons – c’est plutôt une grande chose flexible. C’est vraiment étrange à penser, mais cela vous fait vous demander : qu'est-ce qui est réel, de toute façon ? Animation créée par Sympa.
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Musique par Epidemic Sound https://www.epidemicsound.com
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Nos réseaux sociaux :
Facebook: https://www.facebook.com/sympasympacom/
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Stock de fichiers (photos, vidéos et autres):
https://www.depositphotos.com
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https://www.eastnews.ru
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Si tu en veux encore plus, fais un tour ici:
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FunTranscript
00:00Time would only be a tour of prestidigitation.
00:03Ah yes, we are used to what time flows like a car, always turned to the future.
00:09It creates causes and effects, aligning events one after the other, like dominoes.
00:15Sometimes it stretches and becomes so slow that it feels like it's going to stop.
00:20It is focused on the present moment, because it is the only one that really matters.
00:25But there is a new theory.
00:27It could be that it does not exist at all.
00:33We generally think that space has three dimensions.
00:36The top and the bottom, the left and the right, the front and the back.
00:40And everyone thought that time was a separate thing,
00:43just a universal clock that goes tic-tac in the background, and that is the same for everyone.
00:48That's when Einstein appeared.
00:50He decided to surprise people in 1905 by introducing his theory of restricted relativity.
00:56According to this theory, time is also a dimension, like the others,
01:01and they are all linked in one and the same spacetime.
01:04On this basis, it turned out that time can change depending on the speed at which you move.
01:10Let's now imagine two twins.
01:13The twin A stays on Earth, the twin B goes into space aboard a spaceship,
01:18moving at a speed close to the speed of light.
01:22Let's say 90% of the speed of light.
01:25The twin B travels to a distant star, then returns to Earth.
01:29For the twin B, the journey seems to have lasted only a few years.
01:33But when he returns to Earth, it turns out that the twin A has aged much more.
01:37He discovers that 20, 30 years or more have passed on Earth.
01:41All this is due to a phenomenon called temporal dilation.
01:46This phenomenon occurs when we reach speeds close to those of light,
01:50which slows down time for the traveler compared to someone who stays in the same place.
01:59Ten years later, Einstein proposed his theory of general relativity.
02:03It was then that we learned that time changes not only depending on our speed,
02:08but also depending on gravity.
02:10At the time, Newton thought that gravity was a magical force
02:14that made objects attract each other.
02:17But according to Einstein's theory, it is not a force, but rather a side effect.
02:22Imagine space as a huge piece of fabric.
02:25When you throw a heavy ball on a fabric, it bends.
02:29Now, if you throw small balls all around, they will naturally approach the heavy ball.
02:36In the same way, massive objects such as stars and planets
02:40make space-time curve around them.
02:43When a very heavy object is in space-time, matter curves around it.
02:47This curvature tells objects how to move.
02:51This is what we call gravity.
02:53This idea gave rise to all kinds of interesting predictions
02:57that proved to be accurate later on.
03:00Curvature of light under the effect of gravity,
03:03black holes and time dilation around these black holes,
03:06as in the movie Interstellar.
03:08This theory revolutionized our vision of things.
03:11But we may be at the dawn of another revolution.
03:17Some philosophers have a crazy idea.
03:19They say that the things we believe about time
03:22are just ideas in our heads, and not facts of the physical world.
03:25This idea, that goes along with the traditional vision of time,
03:28is called the Bloch universe.
03:30It relies on Einstein's theory of relativity,
03:33but by extending it and complicating it.
03:35Imagine the universe as a huge sandwich.
03:38This sandwich contains all the moments of time,
03:41past, present and future, at the same time.
03:43Each layer or slice of the sandwich represents a different moment in time.
03:47And all these layers exist simultaneously,
03:50and not one after the other.
03:52In this model of our world,
03:54the past, the present and the future are all equal.
03:57Unlike our daily experience,
03:59where the past no longer exists,
04:01where the future has not yet taken place,
04:03and where only the present is real,
04:05the Bloch universe says that each point in time
04:08is as real as any other point.
04:10Imagine, your birth, the present moment
04:13and what you will do in ten years,
04:15all exist together in this block.
04:17According to this theory,
04:19there is no real temporal flow.
04:21We are used to the fact that time flows from one moment to the next,
04:24even with Einstein's theory.
04:26But in the Bloch universe,
04:28the impression that time flows
04:30is more related to the way we experience events,
04:32when we only remember how time itself works.
04:35It's like reading a magic book,
04:37all the pages exist at the same time,
04:39but you can only live the story page by page.
04:44This implies frightening things,
04:46like fate,
04:47and the question of whether the free will really exists.
04:50If everything is already planned,
04:52does what we do matter?
04:54For example,
04:55the fact that you clicked on this video
04:57was already predetermined in the Bloch universe.
05:00Every choice you made was an illusion.
05:03You are only a program that follows a code,
05:05but that is able to understand the consequences.
05:08This would explain why we order malibu
05:11at midnight,
05:12while knowing that it is a bad idea
05:14and that we are going to bite our fingers.
05:16But some scientists claim
05:18that the flow and direction of time
05:20are unrealistic,
05:22because the cause and effect exist well.
05:25If your birth,
05:26your present moment
05:27and your gray future all existed
05:29at the same time,
05:30you would be able to visit your past at any time
05:33and you would already know what your future looks like.
05:36It could therefore be that all this debate
05:38is simply based on the way
05:40we reconstruct our past stories
05:42and not on the improbable proof
05:44that the future is already done.
05:47There is also an endless battle
05:49between general relativity
05:51and quantum mechanics,
05:52which only adds spice to the debate.
05:55On the one hand,
05:56general relativity plays with time,
05:58as if it were an extensible model.
06:01The flow of time can stretch
06:03or compress depending on speed
06:05or gravity.
06:06On the other hand,
06:07in quantum mechanics,
06:08time is not something
06:10that can be manipulated or modified.
06:12It is a permanent scene
06:14on which the particles
06:15and forces of the universe act.
06:17These two domains have been confronting each other for a long time
06:19and scientists are trying to bring them together
06:21in a coherent theory of everything that exists.
06:24Some even try to merge them
06:26in a logical way,
06:28as with the theory of strings.
06:30The theory of strings may seem frightening,
06:32but it simply says that the entire universe,
06:34with all its particles and all its atoms,
06:36is made up of extremely thin vibrating strings.
06:40Each string can vibrate in different ways,
06:42like the strings of a guitar,
06:44and in many dimensions.
06:46The way these strings vibrate
06:48determines the type of particle they will form,
06:50like an electron or a quark.
06:52Another theory,
06:54called loop quantum gravitation,
06:56claims that space and time
06:58are made up of tiny loops.
07:01Whether they are strings or loops,
07:03they would unfortunately be so tiny
07:05that we do not yet have
07:07a sufficiently powerful equipment to observe them.
07:09Therefore,
07:11as long as we have not tested these theories,
07:13they will not be proven.
07:15What is interesting is that
07:17these two ideas do not really need time
07:19to explain the functioning of the universe.
07:21We consider that objects
07:23and chairs are real,
07:25even if physics does not describe them directly.
07:27We say that they emerge
07:29from the tiny particles that make up the universe.
07:31But time,
07:33we do not know exactly
07:35what it could emerge from.
07:37Whatever the answer,
07:39everything will be fine for you.
07:41If it turns out that time does not really exist,
07:43you could say that everything is useless.
07:45But think about this.
07:47We continue to live our lives,
07:49to experience causality,
07:51to make sense of everything around us.
07:53The impression that we have chosen
07:55to order food at midnight
07:57is extremely tenacious.
07:59So, is the fact that everything can be predetermined
08:01really important?
08:03Anyway,
08:05we are wrong about many things
08:07that we thought were certain.
08:09At present,
08:11the theory of the block universe
08:13and our classical conception of the world
08:15are very far from each other.
08:17But over time, yes,
08:19everything will be fine.