Time doesn't exist! What is the truth of the world that physicists have discovered?!

//Summary - Level-C2//

Physicists question the existence of time, suggesting it may be an illusion rather than a constant reality. While ancient cultures viewed time as cyclical, Newton saw it as absolute, and Einstein introduced relativity, showing time's dependence on speed and gravity. The block universe theory proposes that past, present, and future coexist, challenging our understanding of time as linear.

Time doesn't exist! What is the truth of the world that physicists have discovered?!

The article explores the concept of time, questioning whether it truly exists or is merely an illusion. It begins by referencing the fictional narrative of a man on a mission to save humanity from World War III by manipulating time, using the keyword "TENET."

1.
Existence and Perception of Time: Time is essential to daily life, yet its true nature is debated. The article asks if this perception is an illusion while we experience time flowing from past to future.

2.
Historical Concepts of Time: Ancient civilisations, like Egypt, used the sun and celestial bodies to measure time, viewing it as cyclical due to natural patterns such as the solar cycle and the moon's phases. This changed with scientific advancements in the 17th century when Isaac Newton introduced the idea of absolute time.

3.
Einstein's Theory of Relativity: In 1915, Albert Einstein challenged Newton's notion by proposing that time is relative. According to Einstein, time slows down as speed increases (time dilation). Each person's time experience is unique, depending on their velocity.

4.
Time Dilation and Gravity: Experiments, such as those by Joseph Hafele and Richard Keating, demonstrated that time moves more slowly at higher speeds. Additionally, gravity affects time; the more potent the gravitational force, the slower time passes. This is due to gravity distorting space and time.

5.
Practical Implications: These scientific principles have valuable applications, such as in GPS technology, which requires adjustments for the time discrepancies caused by satellites moving at high speeds.

6.
Philosophical Implications: The article suggests that time might be an illusion human consciousness creates. It introduces the "block universe" theory, which posits that past, present, and future exist simultaneously, and the flow of time is a human perception.

7.
Entropy and Time: The article connects time to the Second Law of Thermodynamics, stating that people perceive time through increased entropy (disorder) in the universe.

8.
Conclusion: While time remains a mystery, the article encourages readers to focus on enjoying the present rather than being preoccupied with the past or future, as time may be an illusion of human perception.

//Main article//

A nameless man is suddenly ordered to carry out a mission. He must escape from the rules of time and save humanity from World War III. The keyword for everything is "TENET." Will he be able to complete the mission with his partner and solve the great mystery?

1)
In this video, physicists explore the mystery of the "nature of time". Time is essential in our daily lives, but does it exist? Or is it just an illusion? A surprising conclusion awaits.

2)
Time is always present in our daily lives.
But what exactly is time?
Does it exist physically?
Or does it not exist at all?

3)
When we are watching a boring movie or taking a boring class, time feels eternal.
However, when we are on a fun trip or playing something we are absorbed in, we feel that time has passed.

Time is so ubiquitous that it would be difficult to answer the question of its true nature.
But would you believe this commonplace existence is an illusion and does not exist?

4)
Today, I would like to introduce you to the existence of time, which is the most familiar yet surprisingly unknown.
There are various theories about when humans first acquired the concept of time, but it is said that this concept was confirmed in ancient Egypt about 5,500 years ago.

The ancient Egyptians built tall, magnificent columns called obelisks and felt the passage of time and the change of seasons through the reflection of the sun's light and their presence.

This was because they were an agricultural civilisation, and changes in time were a matter of life and death.

5)
Similarly, other civilisations often measured time by observing the sun and celestial bodies.

So, what kind of concept of time did these ancient people have?
Most modern people probably think that time flows from the past to the future.

6)
However, the ancients had a very different set of values.
They believed that time was cyclical.

This concept is said to have arisen because the ancient Egyptians lived surrounded by natural cycles such as the rising and setting of the sun, the floods and droughts of the Nile, the waxing and waning of the moon, and the growth cycle of crops.

7)
This concept of time as a cycle is found in ancient Egypt and civilisations worldwide, such as ancient China and ancient Greece.

Several thousand years later, this value system changed significantly around the 17th century.

This was because science developed, and the worldview shifted from one centred on myth and religion to one that also emphasised observation and verification.

8)
In 1687, Isaac Newton, the English physicist genius who discovered the law of universal gravitation, published a book entitled Mathematical Principles of Natural Philosophy, also known as Principia Mathematica.

In it, he proposed an entirely new concept of time.
It was that time is an absolute and constant entity and is perceived as the standard for physical motion.
(The time is to be regarded as an absolute and constant entity, serving as the reference for physical motion.)

9)
Time is an entity that never changes, no matter where you go.

In other words, we perceive the same concept of time, so even if there is a time difference, we share the same time, whether in Japan, Brazil, on the moon, in another galaxy, or even at the edge of the universe.

This may seem obvious to many people.

10)
However, as the saying goes, truth is stranger than fiction, and this is entirely false.
It is impossible to experience precisely the same time in this world.

Let's take a closer look. In 1915, the genius physicist Albert Einstein announced a famous theory that fundamentally destroyed our concept of time.

Everyone has heard of the famous theory of general relativity at least once, but if asked to explain it, you would find it difficult.

11)
Einstein said:
Time is relative. Time slows down as speed increases.
(Time Dilation and Special Relativity.)

This means that time passes more slowly when you move faster, so the time that physically passes is different for each person.

12)
In other words, the time that I want much of experience expands differently

The word "relativity" in the theory of relativity means compared to something.
That is why the theory of relativity is called relativity.

This is why Einstein fundamentally denied the existence of what Newton once proposed and what we commonly experience.

13)
Don't we all share at the same time? What does this mean?
The secret lies in velocity and gravity.

Let's start by looking at the relationship between speed and time.

14)
If I told you that time passes more slowly when you watch a film on an aeroplane than when you watch a movie in a cinema, would you believe me?

I don't think it would be hard to believe.
After all, unless your watch is broken, one minute on an aeroplane and one minute on the ground should be the same.

15)
But in reality, time passes more slowly when you move than when you are standing still.
Why is there such a discrepancy?

To understand this, you must realise that light is a unique entity that always travels at 300,000 kilometres per second, regardless of who observes it.

16)
This is called the principle of constancy of velocity.
Einstein also discovered this.

And the moment light is emitted, it reaches its maximum speed.
In other words, there is no concept of acceleration.
Therefore, it can only be 0 or 100.

17)
Also, whether light travels alongside you, passing you or chasing you, no matter what you do, it always travels at 300,000 kilometres per second.
That is a mysterious property of light.

Let's get back to the subject.
Time always flows slowly in motion, not just in an aeroplane.

18)
The reason for this can be explained with a thought experiment using light.
Let's say we have two boxes.
One is on the ground, and the other is on a rocket.

And suppose the boxes are designed so that light from the ground reaches the ceiling in exactly one second.

When the rocket travels at high speed, it appears to be going diagonally upwards from the outside.
That makes sense.

19)
Meanwhile, light is being shot from the Earth in the same way.
This time, the light will reach the top as it is.

This is also natural.
Now, let's launch the two simultaneously and compare them.

Strangely enough, the light in the box on Earth reaches the ceiling before the light in the rocket.

Why is that?

20)
As explained earlier, light travels at a constant speed due to the principle of constancy of speed.
Therefore, differences in speed never make a difference.

Some people may feel that there are some mistakes.
However, this is because we have a concept of time that time is something that never changes.

21)
But the reality is different.
The time of an object moving at high speed passes more slowly than the time of a stationary object.

But you may still think that this is impossible.

So, I would like to show you an experiment by the American physicist Joseph Halfless and the astronomer Richard Keeling, who had the same question.

22)
1971, they experimented to test whether time slows down when it moves faster.
The experimental procedure involved placing atomic clocks, which never deviate from time, on the ground and in an aeroplane and having the plane fly around the Earth twice.

The reason atomic clocks never go wrong is that they measure the vibrations of atoms to keep time.

And because atomic vibrations are hardly affected by temperature changes or magnetic fields, they can measure time very stably and accurately.

23)
How accurate is it? It's so precise that it's only off by one second every few million years.

A typical quartz clock deviates by about 11 inches, so you can see how atomic clocks are not prone to deviation.
Now, back to the main topic.

24)
The aeroplane orbited the Earth as planned.

The first time, it went east; the second time, it went west.
After the second orbit, we checked to see if there was a time difference.

We found a minimal difference.
The difference was 59 nanoseconds.

This result proves that the difference is slight, proving that Einstein's theory is correct.

This discovery destroys our values, but at first glance, it may seem to have nothing to do with us.

25)
However, it has a lot to do with it.
Without the right conditions, we cannot use GPS properly.

GPS uses artificial satellites, but artificial satellites move at about 14,000 kilometres per hour.

Considering that a typical passenger plane can travel at a maximum speed of 900 kilometres per hour, you can see how fast artificial satellites move.

26)
Converted to Mach, this is about Mach 11.6. If you travel from Hokkaido to Okinawa at this speed, it will take you about 11 minutes. That's fast.

Because artificial satellites move at such incredible speeds every day, GPS will continue to drift and become useless if the time difference is not corrected.

It's scary.
Let's all thank Einstein.

27)
From this, we can say that the act of moving is moving at a speed several hundred millionths faster than the speed of light.

That is why moving slows down time.

Of course, in everyday travel, there is not even a minute's difference in a lifetime.
But the closer you get to the speed of light, the slower time becomes.

28)
In other words, for example, if you travel through space at super-high speed for a year, when you return to Earth, ten years will have passed on Earth.

So, although you cannot manipulate time at will, it is both realistic and theoretically possible to travel to the future at a similar age to the present.

I think you have now understood that speed differences create time discrepancies.
From here, let's look at the relationship between gravity and time.

29)
At first glance, time and gravity are entirely separate elements, so it may seem that the only relationship between them is that training in high gravity builds muscles more efficiently.

However, it has been mathematically and physically proven that time passes more slowly in proportion to the strength of gravity.

30)
But why is this?
To understand, let's take a look at gravity.
Gravity is, in a word, a distortion of space.

Imagine that there is a piece of cloth here.
Imagine that this cloth is space.

And then imagine that you put a ball on it.
Naturally, the cloth will sink under the weight of the ball.

31)
Then, try placing another ball nearby.
You will see that the lighter ball is pulled towards the heavier ball and sinks.

This is what we call gravity.
The same principle applies to satellites orbiting planets such as the Earth.

32)
However, while gravity is represented as acting directly downwards, it is distorted into a space of five or more dimensions.

This is called the Brain World hypothesis.
The details will be explained in another video, as they are long.

33)
Now that we know gravity, let's return to the question from the beginning.

Why does gravity slow down time?
Einstein answered:

Gravity is not a force of attraction but a curvature of space and time.

34)
It means that in this world, objects appear to be attracted to each other, but this is because gravity bends space and time itself.

Therefore, gravity does not pull on objects, but space itself is pulled by gravity, which is why we experience gravity.

35)
This is why even light, which has zero mass, is helplessly bent by gravity.
This is because light travels through space itself.

Let's look at another concrete example.
It's the same thought experiment as before.

36)
Suppose it takes one second for light to travel from point A to point B.
But let's add a vital source of gravity.

As mentioned before, a solid gravitational source will distort the surrounding space.

37)
As an experiment, let's compare light travelling through nothing with light travelling through a place with intense gravity.

After one second of light travelling through nothing, light travelling through a place where space is distorted will have travelled only about half the distance.
This is why time slows down in the presence of gravity.

38)
This is the same situation as explained in the section on speed and time.
However, some people may still not be convinced.
I want to present an experiment to check whether gravity affects time.

This is the Poundrebka experiment carried out in 1960.

39)
They tried to see if there would be a difference in time between the top of a 22.5m high building and the basement.
Again, an atomic clock was used.

Usually, it is hard to imagine that there would be a difference in time.
It is common sense and impossible.

However, the experiment's results showed that even at a height of only 22.5m, time passes more slowly in the basement by 1/210 trillionth of a second per day.

40)
This phenomenon occurs because the cellar is closer to gravity.

Of course, you won't notice the effect in your everyday life.
But it is different when it comes to the sun or a star that is even heavier than the sun.

41)
Incidentally, a scene in Christopher Nolan's film Interstellar symbolises how gravity slows down time.
If you want to see how gravity slows down time, watch it.

I recommend this film because it reaches the ultimate level of story and visual beauty.

So, from the above, I think you understand that there is no such thing as absolute time in this world, and time is only relative.

In other words, the time I experience and the time I experience are, strictly speaking, completely different.

Isn't this a rather unusual story so far?
But we will break even more normal concepts, so be prepared.

42)
So what is time anyway?
The answer is that it may be an illusion created by the human brain.

What does that mean?
To understand this, we need to know how we humans perceive time.

Let's look at some specific examples.

43)
Human beings are born, grow and age.
If you drop an egg, it breaks.
Ice melts and eventually evaporates.

If you don't do your homework, you will be scolded.
You will be scolded even more if you don't do your homework during the summer holidays.

44)
Thus, we can recognise time only by recognising the difference between past and present and present and future, i.e. the causal relations between things.

Conversely, if there is no causal relationship, it can be said that time does not flow there.

However, causal relationships in this world are always one-way, from the past to the future.
Future events can't affect the past or present.

At least there is no case in current science where this has been confirmed.

45)
So why is this world designed so that time only flows from the past to the future?

This is said because this world is governed by the "Second Law of Thermodynamics."

The "Second Law of Thermodynamics" is called the "Law of Increasing Entropy."

Entropy is a concept that describes the degree of disorder or disorder in things.

46)
That doesn't make sense.
The law means the world will become more complex if left alone.

If you drop an egg, it will crack.
Ice melts and eventually evaporates.

If you don't do your homework, you get scolded.
If you don't do your summer homework, you get even more scolded.

Things are designed to become more complex in this way.

47)
It can be said that people feel time precisely because they can recognise this process of increasing entropy.

So, it can be said that time itself does not exist, but that consciousness allows us to experience time.

Some might say that this is just philosophy.
However, one theory that explains this scientifically is the "block universe".

48)
The block universe is a theory that the past, present and future all exist as a single block.
Because it is a single block, the past, present, and future exist simultaneously.

The flow from past to future and the progression of time are human subjective experiences and do not exist as a physical reality.

In other words, to put it simply, the end of this world was determined the moment it was created, and the time we feel is just an illusion because of our brain's ability to retain memories.

49)
However, if this were to happen, the future of this world would already be set, and it would be impossible to change it.

This would be unfortunate; many people worldwide are critical of this theory.

However, this theory that time does not exist is supported by many scientists, including Max Tegmark, a professor of physics at the Massachusetts Institute of Technology, and Julian Barber, a British physicist who has studied Einstein's theory of relativity and quantum physics for 30 years.

50)
Although humanity has incredible scientific power, we have not yet been able to unravel the actual structure of this world.

So, the truth remains unknown.
If you have time to worry about the future or the past, you should enjoy this moment to the fullest.

Indeed, time may not exist.
But whether time exists or not has no bearing on enjoying this moment.

51)
It is said that many people today are so caught up in the past and future that they fail to enjoy each day.
I understand this; everyone is busy.

But if you make excuses and put off enjoying the present, you will regret it in the future.

You only have one life.
Whether your destiny is predetermined or not, let's have fun and laugh. Thank you for watching to the end.

Time doesn't exist! What is the truth of the world that physicists have discovered?!

https://www.youtube.com/watch?v=PBF4F6_qpVM

Add info)

TENET (2020) - IMDb 7.3/10

https://www.imdb.com/title/tt6723592/

TENET - Official site

https://wwws.warnerbros.co.jp/tenetmovie/index.html

[Spoiler Alert] A complete analysis of Nolan's most challenging film, "TENET"!

https://screenonline.jp/_ct/17393355

Film [TENET] Walkthrough - A thorough explanation and analysis that is easy for liberal arts students

https://note.com/iso_zin_/n/n1735240d4cfa

[Latest version] TENET - An explanation of all the events in all scenes and a timeline map [Compilation] [Spoiler]

https://www.youtube.com/watch?v=HMEXEU3UpcA&t=3409s

Film, Interstellar (2014) - IMDb 8.7/10

https://www.imdb.com/title/tt0816692/