Can time actually turn around or not?

We always want to be able to turn back time to fix a mistake, to experience old memories again. But now, this is absolutely impossible, so why can't we go back in time like retorting a watch or somehow but we still haven't found it?

Why can't turn back time?

In a study published in the journal Physical Review Letters, a group of physicists re-defined the " Arrow of Time" - a concept that describes the journey incessantly. forward of time - and gives a different perspective on how time is expressed on universal scales.

For a long time, time has been described by a "hypothesis of the past" , assuming that any system is started from a low thermodynamic state and then controlled. by thermodynamics, its thermodynamic temperature increases. In short: the past is low thermodynamics and the future is high thermodynamics - a concept also known as the thermodynamic time asymmetry.

Even if time does not pass, we can still assign it a dimension, called a time arrow. This is an abstract concept that simply means that we can define an order of events. A time arrow points from the past to the future, from previous events to the following events. It is a one-way time in which everything happens.The important thing here is to make the difference between a flow of time and a dimension of time.

Imagine looking at each frame one of a movie reel. We can easily define a directional dimension in one direction according to the rotation based on which frames are first and which ones are later. We do so despite the fact that we are looking at static images of events and there is no movement in the frames at all. Each frame is a frozen photo in time.

If this is applied on a universal scale, it is assumed that the Big Bang explosion created the Universe in a low thermodynamic state, ie the minimum thermodynamic state. Over an endless period of time, because the Universe has expanded and cooled down, the thermodynamics of this large-scale system has increased. Therefore, according to the above hypothesis, the basic time is linked by the degree of thermodynamics, or disturbance, in our Universe.

Immediately after the Big Bang, there is some observational evidence that indicates that the environment of the Big Bang is extremely hot with the extremely chaotic state of elementary particles. As the Universe matured and cooled, gravity began to have a greater influence, making the Universe more and more orderly and more complex - from cool clouds of gas, stars formed and The planets are evolved from the collapse of gravity. Finally, the elements can combine together into organic matter, gradually evolving to bring life and people, thereby forming concepts of space and time.Thus, on the whole of the Universe, "chaos" has decreased significantly, rather than increased as the "hypothesis of the past" has assumed.

Scientist Flavio Mercati of Perimeter Institute for Theoretical Physics in Ontario (Canada), a co-investigator, argues that this is how the thermodynamic problem is measured. Since thermodynamics is a physical quantity with different representational dimensions (like energy and temperature), an external frame of reference is required to be measured."This can be done with the subsystems of the universe when the rest of the universe will be established as a reference for them. But the whole universe - by definition - has nothing outside." In order to be able to identify these things, " Mr. Mercati wrote in an email reply to Discovery News science and technology news.

Besides, physical equations don't even provide one-way in time. Time can go back and the laws of physics remain unchanged. You might think that this may be just a blessing for physicists. If the dimension in which time is directed is missing in physical equations, they cannot tell us the whole story.Because it is impossible to perceive one-way time from mathematical equations, it does not mean there is no one-way time in the real world.

Flavio Mercati scientist.

Flavio Mercati took a somewhat complicated example when he said even in the real world, at the atomic level, almost every process is reversible in time. If, during a subatomic process, two particles, a and b, fall and collide, they often pop up and separate again. If you watch the movie recording of such a process and then watch it run backwards, you will not be able to tell which spin has taken place. The process of reversing time still follows the laws of physics.

To be specific, Mr. Mecati took an example of two new particles, for example c and d, that were born and flew away from each other. Again, you will not be able to be sure of the true order of events if you watch the film of this process because the laws of physics state that the reverse process is also possible. Particles c and d may collide to produce particles a and b. Therefore, you cannot assign a time arrow to specify the process in which order occurred.

This is in stark contrast to the events that occur around us in everyday life in which we don't have to bother to determine in which direction direction. For example, you never see smoke above a chimney focusing on the chimney and then being swallowed back inside. Similarly, you can't 'stir' the sugar from a cup of coffee once it's dissolved, and you never see a pile of ashes in the fire- burning ash to become a log again.

So what distinguishes these events from subatomic events? How did most of the phenomena we see around us never happen the opposite? Certainly everything ends up being composed of atoms and at that level everything is reversible. So at what stage in the evolution from atoms to smoke to chimneys, to cups of coffee and logs, does a process become irreversible?

It is all due to an important law in physics called the second law of thermodynamics. The field of thermodynamics studies heat and its relationship with other forms of energy. Astronomer Arthur Eddington once stated that the second law of thermodynamics has a supreme position in every law of nature. There are also three other laws of thermodynamics concerning how heat and energy can transform each other, but no law is as important as the second.

The second law of thermodynamics states that everything is worn down, cooled, separated, aged and decomposed . It explains why sugar dissolves in coffee and never happens in reverse. It also states that a stone in a glass will melt because the heat is always transmitted from the warmer water to a colder stone and never transmitted back.

Complexity is a non-representational quantity that, in its most basic form, describes how complex a system is. Therefore, if you look at our Universe, complexity is directly linked to time, as time goes by, the Universe becomes increasingly more structured, ie more orderly. Mercati said: "The question we sought to answer in our study was: what sets these systems in such a very low thermodynamic state at the beginning? We are: gravity and its trend in creating order and structure from chaos ".

Often, the concept of time is described by the 'past hypothesis' , which assumes that all systems start at the entropy threshold (the unit of measurement of heat dissipation or absorption when a physical system moves extremely low state, then the thermodynamic process takes place causing the entropy to rise. In other words, the past is a low entropy and the future is a high entropy, this is an asymmetric time hypothesis. In short terms, entropy is a measure of disorder in a system, which is all measure How much is disturbed.

To experiment with this idea, Mr. Mercati and colleagues created basic computer models to simulate particles in a model universe. They found that regardless of how the simulation is run, over time the complexity of the universe is always increasing and never decreasing.

From the Big Bang explosion, the Universe started in the lowest complex state (such as "hot soup bowl" of chaotic particles and energy). Then, because the Universe cooled down to a state where gravity began to take its place, gas gathered together, stars formed and galaxies developed. The universe becomes more complex and gravity is the driving force for this complexity.

When the Universe reaches adulthood, subsystems become independent enough so that other forces form the conditions for the time arrow present in low thermodynamic systems.In these subsystems, like daily life on Earth, thermodynamics can displace, creating a "thermodynamic time arrow".

On a universal scale, our perception of time is controlled by the continuous growth of the complex, but in these subsystems, the dominant thermodynamics."The universe is an increasingly complex structure," Mercati said, "The universe is made up of large galaxies separated by large distances. In the very long past, they congregated near Our conjecture is: our time perception is the result of a law of irreversible growth of the complex. "

The next step of the research will be to look for observational evidence, which Mercati and the team are working on.". we don't know if there is any support but we know the kind of experiment that can test our idea. That's the cosmic observations . " Currently, he does not disclose what kind of cosmic observations will be studied but says they will publish information in an upcoming interesting study.

In addition, physics professor Jim Al-Khalili of Surrey University - author of the hugely popular Black Holes book, Wormholes and Time Machines - said the so-called "lapse of time" is only one present. hallucinations, the laws of physics say nothing about the flow of time. They tell us how things like atoms, pulleys, levers, clocks, missiles and stars behave when under the influence of different forces at certain times in time. , and if the state of a system is given at a given time, the laws of physics give us rules that calculate its possible state at some future time.

Professor Jim Al-Khalili.

However, no place contains a sign of time passing. The concept of time passes, or moves in a certain way, is completely absent from physics. We find that, like space, time simply exists; just like that. Moreover, Albert Einstein's genius also held the view that time was hallucination and he even performed it when trying to comfort a close friend's widow when she said she should relax the perception that the present time is nothing more special than any other time in the past or in the future; All times exist together.

So we can see how difficult it is to see time as a concept, even if Jim Al-Khalili is happy that if you try to understand the problem of time, you should be ready to do it. familiar with Einstein's special theory of relativity in which he bound time to space into four-dimensional spacetime. Professor Jim Al-Khalili concludes that turning back time is like tricking human senses on the level of quantum physics , but if done on quantum physics, it is still possible.

Indeed, in February 2015, Professor Kater Murch of the University of Washington and colleagues conducted a quantum experiment. They put a circuit board in the microwave, then fired light photons here - where the quantum field of the particle interacted with the circuit board. After the first photons passed, the computer's analysis results were "hidden" and the experts would predict the results of the next shot. According to Murch, this is like predicting future events, and the highest probability is only 50%.

Meanwhile, Murch's team thinks that if the state and future development of each particle are known, the ability to correctly predict the flight results of photons in the experiment is up to 90%. According to him, atomic particles are not shaped until humans measure them.That means, in the past, particles were not defined, but when people conducted research (in the future), they were in shape, weight or full speed. Understand simple, the very action in the future has changed what happened in the past.

If this theory is correct, then time and space are symmetrical. In other words, we today only feel the rapid passing of time, but in reality, time is a two-way 'arrow' and can be reversed completely.