Jens Berges' blog part 8

Is time real?

I have been diagnosed with a terminal lung condition. As I move ever closer to the end of my life, I have become more interested in fundamental issues such as consciousness (the perception of the self), free will, even the reality of time.

Will I soon be gone forever, or can time be reversed? Is our sense that time flows just an illusion?

To start with, we have all grown familiar with the fact that our perceptions may be far off the truth.

Take, for example, our sense of the earth as a flat base from which buildings, even mountains arise. But the earth is a spinning, misshaped ball traversing space at extreme speed. We can measure this, thanks to Copernicus and Galilei, but nobody can sense the earth's spin, or its speed. When we sense our existence on still, flat ground, this is, in fact, an illusion.

There are arguments that the flow of time is just another illusion.

As Einstein discovered, time is relative, depending on the speed by which objects move.

According to Einstein, time is a fourth dimension in space-time, and the movement of an object through space and time can be blotted as a series of dots on a 4-dimensional diagram of length, width, height, and time. This has been shown to be correct in many measurements.

But why limit such a diagram to single objects? If everything in the universe is included in this 4-dimensional diagram, then the flow of time vanishes.

In such a so-called "block universe", everything, past, present, or future, exists simultaneously.

To understand the concept of the block universe, imagine you read a novel, printed as a book, page by page, word by word, from start to finish. This is a directional event. If you read the words backwards, the book makes no sense to you.

But the reality is that all the pages, and all the words, are still there after you read them. You can count, or measure, them forwards or backwards. Thus, the flow of time you experience while reading the book, is a structural construct of the human mind.

This construct, of course, creates a beautiful story, an illusion that is much more than black symbols on paper.

In the measured block universe, time does not flow.

But does this explanation (that the past, present, and future exist at the same time) satisfy my desire to be myself at a younger age?

Unfortunately not, just as the metaphor of the book (where the words of the beginning of the story and the words of the end of the story exist simultaneously) does not capture the book's entertainment value.

In physics, too, the concept of a block universe is challenged. (Everything gets challenged in physics.)

In a block universe, anything would be determined. An observer could move up and down on any axis, including backwards and forwards on the time axis, and this would not violate the integrity of the system. Every cause has a clear effect, and every effect can be traced to a cause. The block universe idea does not allow randomness.

However, it is a common understanding in physics that on the subatomic level, there is randomness.

Subatomic particles initially are waves. Only when there is interference, they become particles. This is called the "collapse of the wave function". Many parameters of these particles, such as their positions, are probabilistic. They may be more likely to be found in one place or another, but where exactly they will be upon the collapse of their wave-like existence, is thought to be uncertain. Thus, there is randomness, which negates the reversible flow from cause to effect, and thus time itself.

A well-established concept of physics, the second law of thermodynamics, also sees time as flowing from the past to the future, with no option of reversal.

This law of physics declares that in a closed system, heat exchange only happens, on a time axis, from a warmer area to a colder area, until everything has a uniform temperature.

The second law of thermodynamics can be formulated in many different ways. It also means that in any closed system, everything moves, on a time axis, from being organized to being disorganized (a state of higher entropy).

Time is probably real. But even if it were just an illusion, as in a block universe, this would not solve my problem. What I regret while facing death is anyway not the flow of time in itself, but the fact that my time, or whatever (beautiful) illusion this may be, is coming to an end.