We usually think of time simply, fundamentally, as flowing equally everywhere, from past to future, as measured by clocks, to the indifference of everyone in the world.
It is believed that events in the universe occur in the order of past, present, and future in the flow of time.
The past is set, the future is open… … .
But it turned out that all of this was wrong.
Each and every characteristic aspect of time is a product of the errors and approximations of our vision.
Examples include the previously mentioned flatness of the Earth and the rotation of the Sun.
But as human knowledge grew, the concept of time gradually began to be unveiled.
What we call 'time' is a complex collection of structures, or layers.
As the research progressed deeper and deeper, time gradually lost this layer, piece by piece.

--- p.10~11

This is more important than the speed at which time passes.
This is the essence of time.
The secret of time lies in the vibrations of our pulse, in the riddles of our memories, in the anxiety about the future.
That's what it means to think about time.
So what exactly is the flow of time? How can it be defined within the grammar of the world? What, among the mechanisms of this world, distinguishes the past, which already existed, from the future, which has yet to come? Why are past and future so distinct? Physics of the 19th and 20th centuries confronted these questions, and to make matters worse, they were baffled by the unexpected fact that time flows at different speeds depending on the location.
Because in the fundamental laws that explain the mechanisms of the world, there is no difference between the past and the future (the difference between cause and effect, memory and hope, regret and will).

--- p.29

It is meaningless to ask which moment in the sister's life corresponds to the 'now' in Proxima b.
This is like asking which football team won the basketball championship, or how much money a lottery player made, or how much a musical note weighs.
Soccer teams play soccer, not basketball, swallows don't make money, and sound has no weight, so these are all wrong questions.
The basketball championship should be for basketball teams, not soccer teams.
Making money should be done for the people in society, not for the lotteries.
Likewise, the concept of 'present' should refer to something close to us, not something far away.
Our 'present' does not apply to the entire universe.
You can think of it as a bubble that is close to us now.

--- p.52

The world can be thought of as being made up of 'things'.
That it is made of matter, of something 'substantial', something that 'exists in the present'.
Or you could think of it as a world made up of 'events'.
It is a world that is seen as made up of something that happens by chance, through a process, through something that 'occurs'.
That which is not permanent, is constantly changing and impermanent.
In fundamental physics, the destruction of the concept of time is a collapse of the first of two perspectives, not the second.
It is not that stability in unchanging time has been realized, but rather that temporariness has come to exist anytime, anywhere.
Thinking of the world as a totality of events and processes is the best way to capture, understand, and explain the world.
This is the only way to reconcile it with the theory of relativity.
The world is a totality of events, not things.
--- p.105

The distinction between past, present, and future is not an illusion.
This is the temporary time structure of this world.
However, the temporal structure of the world is not the temporal structure of presentism.
The temporal relationships between events are much more complex than we previously thought, but that doesn't mean they don't exist.
Intimacy doesn't create world order, but it doesn't create illusions either.
Just because we are not all aligned doesn't mean there are no relationships between us.
Change and events are not illusions.
What we've found is that events don't happen according to one global order.

--- p.118

We could say that we measure time with a clock, but this is impossible.
Duration can be measured by looking at the clock at two different moments, because we are always in one moment, not two.
We see only the present in the present.
We can see what we interpret as 'traces' of the past, but there is a big difference between seeing traces of the past and perceiving the passage of time.
Augustine understood that the source of this difference was that the perception of the passage of time was internal.
It is a part of our inner self, a trace of the past that remains in our brain.

--- p.187~188

So, in the end, we can only speak of this single time, the uniform, universal, and ordered time we experience, rather than of the countless times that exist in the world.
This time is an approximation of an approximation of an approximation of an approximation of the world, described from our special perspective as humans, settled in the flow of time by the growth of entropy.
According to Ecclesiastes 128 in the Bible, there is a time for birth and a time for death.
Our time is a complex, multi-layered concept, with numerous distinct properties derived from various approximations.
The reason there are so many conflicting opinions about the concept of time is because we do not understand its complex and multi-layered aspects.
We are making the mistake of not seeing these different layers.
This is the physical structure of time that I have come to know after spending my entire life wandering around it.

--- p.203~204