# Creating a time machine is possible. Experiments with time. Theoretical part

Just the other day, after reading the article Time Travel and ProgrammingI got the idea of experimental studies that would provide practical answers to questions about time travel. But before moving on to experiments, it is necessary to develop a theoretical justification for the possibility of overcoming time between the past and the future. What actually I did in the last days. The study is based on Einstein's theory of relativity and relativistic effects, while also affecting quantum mechanics and superstring theory. I think I managed to get positive answers to the questions posed, consider hidden dimensions in detail, and simultaneously get an explanation of some phenomena, for example, the nature of wave-particle duality. And also consider practical ways of transferring information between the present and the future. If you are also concerned about these issues, then welcome to cat.

Usually I do not do theoretical physics, and in reality I lead a fairly monotonous life doing software, hardware, and answering the same questions from users. Therefore, if there are inaccuracies and errors, I hope for a constructive discussion in the comments. But I could not get past this topic. Every now and then new ideas appeared in my head, which eventually formed into a single theory. Somehow, I’m not torn myself to go to the past or future in which no one expects me. But I suppose that in the future it will be possible. I'm more interested in solving applied problems related to the creation of information channels for transmitting information between past and future. As well as questions about the possibility of changing the past and the future.

Traveling in the past is associated with a large number of difficulties that greatly limit the possibility of such a journey. At this stage in the development of science and technology, I think it is premature to undertake the implementation of such ideas. But before you understand whether we can change the past, you need to decide whether we can change the present and future. After all, the essence of any changes in the past comes down to a change in subsequent events relative to a given point in time, to which we want to return. If we take the current moment of time as a given point, then the need to move to the past disappears, as well as a large number of difficulties associated with such a movement. It remains only to find out the chain of events that should happen in the future, and try to break this chain in order to get an alternative development of the future. In fact, we don’t even need to know the complete chain of events. It is necessary to know reliably whether one specific event in the future (which will be the object of research) will come true. If it comes true, it means that the chain of events has made this event come true. Then we have the opportunity to influence the course of the experiment and make sure that this event does not come true. Will we be able to do this? The question is not clear yet. And the point is not whether we can do this (an experimental setup should allow this to be done), but whether an alternative development of reality is possible. Then we have the opportunity to influence the course of the experiment and make sure that this event does not come true. Will we be able to do this? The question is not clear yet. And the point is not whether we can do this (an experimental setup should allow this to be done), but whether an alternative development of reality is possible. Then we have the opportunity to influence the course of the experiment and make sure that this event does not come true. Will we be able to do this? The question is not clear yet. And the point is not whether we can do this (an experimental setup should allow this to be done), but whether an alternative development of reality is possible.

First of all, the question arises - how can we reliably find out what has not happened yet? After all, all our knowledge about the future always comes down only to forecasts, and forecasts are not suitable for such experiments. The data obtained during the experiment should conclusively prove what should happen in the future as an event that has already occurred. But in fact there is a way to obtain such reliable data. If you should carefully consider Einstein's theory of relativity and quantum mechanics, then you can find a particle that can connect the past and the future in one time line and transmit the necessary information to us. A photon acts as such a particle.

The essence of the experiment comes down to the famous experiment with two slots with a deferred choice, which was proposed in 1980 by physicist John Wheeler. There are many options for implementing such an experiment, one of which was given on Habré . As an example, consider the experiment with a deferred choice, which was proposed by Scully and Drul:

A beam splitter is placed in the path of the photon source - the laser, which is a translucent mirror. Typically, such a mirror reflects half of the light incident on it, and the other half passes through. But photons, being in a state of quantum uncertainty, falling on a beam splitter will choose both directions at the same time.

After passing through the beam splitter, the photons enter the down converters. A down converter is a device that receives one photon at the input and produces two photons at the output, each with half the energy (“down conversion”) from the source. One of the two photons (the so-called signal photon) is directed along the original path. Another photon produced by a down converter (referred to as a single photon) is sent in a completely different direction.

Using fully reflective mirrors located on the sides, the two beams are again assembled together and sent to the detector screen. Considering the light in the form of a wave, as in Maxwell's description, an interference pattern can be seen on the screen.

In the experiment, it is possible to determine which path to the screen the signal photon chose, by observing which of the down converters emitted a single photon partner. Since it is possible to obtain information about the choice of the path of the signal photon (even though it is completely indirect, since we do not interact with any signal photon), observation of a single photon prevents the occurrence of an interference pattern.

### So. And here experiments with two slits

The fact is that idle photons emitted by down converters can travel a much greater distance than their signal photons partners. But no matter how far the idle photons go, the picture on the screen will always coincide with whether the idle photons are fixed or not.

Suppose that the distance of an idle photon to the observer is many times greater than the distance of the signal photon to the screen. It turns out that the picture on the screen will pre-display the fact whether they will observe a single partner photon or not. Even if the decision to observe a blank photon is made by a random event generator.

The distance that a single photon can travel does not affect the result displayed on the screen. If you drive such a photon into a trap and, for example, force it to repeatedly spin around the ring, then you can stretch this experiment for an arbitrarily long time. Regardless of the duration of the experiment, we will have a reliably established fact of what should happen in the future. For example, if the decision about whether we will “catch” a blank photon depends on the flip of a coin, then already at the beginning of the experiment we will know “how the coin will fall”. When a picture appears on the screen, it will already be a fait accompli even before a coin toss.

There is an interesting feature that seems to change the causal relationship. We may ask - how can a consequence (which happened in the past) form a cause (which should happen in the future)? And if the cause has not yet come, then how can we observe the effect? To understand this, we will try to delve into Einstein's special theory of relativity and deal with what is actually happening. But in this case, we will have to consider the photon as a particle, so as not to confuse quantum uncertainty with the theory of relativity.

### Why exactly a photon

This is exactly the particle that is ideally suited for this experiment. Of course, other particles, such as electrons and even atoms, also possess quantum uncertainty. But it is the photon that has the maximum speed of motion in space and the concept of time itself

*does not exist*for it , so it can freely cross the time dimension, connecting the past with the future.

### Picture of time

To represent time, it is necessary to consider space-time as a continuous block stretched in time. The slices forming the block are present moments for the observer. Each slice represents space at one point in time from its point of view. This moment includes all points of space and all events in the universe, which are presented to the observer as happening at the same time. Combining these sections of the present, arranging one after the other in the order in which the observer experiences these time layers, we obtain a region of space-time.

But depending on the speed of movement, sections of the present will divide space-time at different angles. The greater the speed of movement relative to other objects, the greater the cutting angle. This means that the present time of a moving object does not coincide with the present time of other objects relative to which it moves.

In the direction of movement, the slice of the present time of the object is shifted into the future relative to motionless objects. In the opposite direction of movement, the slice of the present time of the object is shifted into the past relative to motionless objects. This is because the light flying at the meeting of a moving object reaches it earlier than the light catching up with a moving object from the opposite side. The maximum speed of movement in space provides the maximum angle of displacement of the current moment in time. For the speed of light, this angle is 45 °.

### Time dilation

As I already wrote, the concept of time

*does not exist*for a particle of light (photon) . Let us try to consider the cause of this phenomenon. According to Einstein's special theory of relativity, as the speed of an object increases, time slows down. This is due to the fact that as the speed of a moving object increases, it is necessary for light to cover an ever greater distance per unit of time. For example, when the car is moving, its headlights need to travel a greater distance per unit of time than if the car was parked. But the speed of light is the limit and cannot increase. Therefore, folding the speed of light with the speed of the car does not increase the speed of light, but leads to a slowdown in time, according to the formula:

where

*r is the length of time, v is the relative speed of the object.*

For clarity, consider another example. Take two mirrors and place them opposite one above the other. Let us assume that a ray of light will be reflected many times between these two mirrors. The movement of the ray of light will occur along the vertical axis, at each reflection, measuring time as a metronome. Now let's start moving our mirrors along the horizontal axis. With increasing speed, the trajectory of the light will tilt diagonally, describing a zigzag movement.

The greater the horizontal speed, the more the trajectory of the beam will be tilted. When the speed of light is reached, the considered trajectory of movement will be straightened in one line, as if we had stretched the spring. That is, the light will no longer be reflected between the two mirrors and will move parallel to the horizontal axis. So our "metronome" will stop measuring the passage of time.

Therefore, there is no measurement of time for light. A photon has neither past nor future. For him, there is only the current moment in which it exists.

### Space compression

Now let's try to figure out what is happening with space at the speed of light in which photons reside.

For example, take an object 1 meter long and accelerate it to near light speed. As the speed of the object increases, we will observe a relativistic reduction in the length of the moving object, according to the formula:

where

*l is the length and v is the relative speed of the object.*

By the word "we will observe," I mean a stationary observer from the side. Although from the point of view of a moving object, stationary observers will also shorten in length, because observers will at the same speed move in the opposite direction relative to the object itself. Note that the length of an object is a measurable quantity, and space is a reference point for measuring this quantity. We also know that the length of an object has a fixed value of 1 meter and cannot change relative to the space in which it is measured. This means that the observed relativistic contraction in length indicates that space is decreasing.

What happens if an object gradually accelerates to the speed of light? In fact, no matter can accelerate to the speed of light. You can get as close as possible to this speed, but to achieve the speed of light is not possible. Therefore, from the point of view of the observer, the length of the moving object will be infinitely reduced until it reaches the minimum possible length. And from the point of view of a moving object, all relatively motionless objects in space will be infinitely compressed until they are reduced to the minimum possible length. According to Einstein's special theory of relativity, we also know one interesting feature - regardless of the speed of the object itself, the speed of light always remains unchanged as a limiting value. This means that for a particle of light our entire space is compressed to the size of the photon itself. Moreover, all objects are compressed,

Here you can see that the formula for relativistic reduction in length makes it clear to us that at the speed of light all space will be compressed to zero size. I wrote that space will be compressed by the size of the photon itself. I believe both conclusions are correct. From the point of view of the Standard Model, a photon is a gauge boson that plays the role of a carrier of fundamental interactions of nature, the description of which requires gauge invariance. From the point of view of the M-theory, which today claims to be the Unified theory of everything, it is believed that the photon is an oscillation of a one-dimensional string with free ends, which has no dimensionality in space and can contain convoluted measurements. I honestly don’t know by what calculations the proponents of the theory of superstrings came to such conclusions. But the fact that our calculations lead us to the same results, I think, suggests that we are looking in the right direction. The calculations of the theory of superstrings have been cross-checked for decades.

So. What have we come to:

- From the point of view of the observer, the entire space of the photon is minimized to the size of the photon itself at each point of the trajectory of motion.
- From the point of view of the photon, the trajectory of motion in space is minimized to the dimensions of the photon itself at each point in the space of the photon.

### Let's consider what conclusions follow from all that we learned:

- The line of the current time of the photon crosses the line of our time at an angle of 45 °, as a result of which our measurement of time for a photon is a non-local spatial measurement. This means that if we could move in the space of the photon, then we would move from the past to the future or from the future to the past, but this story would be composed from different points of our space.
- The space of the observer and the space of the photon do not directly interact, they are connected by the movement of the photon. In the absence of movement, there are no angular differences in the line of the current time, and both spaces merge into one.
- A photon exists in a one-dimensional spatial dimension, as a result of which the motion of a photon is observed only in the spatio-temporal dimension of the observer.
- There is no movement in the one-dimensional space of the photon, as a result of which the photon fills its space from the start to the end point, at the intersection with our space, giving the initial and final coordinates of the photon. This definition says that in its space the photon looks like an elongated string.
- Each point of the photon space contains a projection of the photon itself in time and in space. It means that a photon exists at every point of this string, representing different projections of the photon in time and space.
- At each point of the photon's space, the full trajectory of its motion in our space is compressed.
- At each point in the observer’s space (where the photon can stay), the complete history and trajectory of the photon itself is compressed. This conclusion follows from the first and fifth points.

### Photon space

Let's try to figure out what the space of a photon is. I admit, it's hard to imagine what a photon space is. The mind clings to the familiar and tries to draw an analogy with our world. And this leads to erroneous conclusions. To imagine another dimension, you need to drop the usual ideas and start thinking differently.

So. Imagine a magnifying glass, collecting in focus the whole picture of our space. Let's say we took a long tape and placed the focus of the magnifier on this tape. This is one point in the photon space. Now move the magnifying glass a little parallel to our tape. The focus point also moves along the tape. This is another point in the space of the photon. But how are these two points different? At each point there is a panorama of the entire space, but the projection is made from another point of our space. In addition, while we were moving the magnifier, some time passed. It turns out that the photon space is somewhat similar to a film shot from a moving car. But there are some differences. The photon space has only a length and does not have a width, therefore there is only one dimension of our space recorded - from the initial to the final trajectory of the photon. Since the projection of our space is recorded at each point, then in each of them there is an observer! Yes, yes, because at each point, simultaneous events are recorded from the point of view of the photon itself. And since the initial and final trajectories of the photon are located in the same time line, these are simultaneous events for the photon that affect it at different points in their space. This is the main difference from the analogy with film strip. At each point of the photon space, the same picture is obtained from different points of view, and reflecting different points in time. that affect him at different points in their space. This is the main difference from the analogy with film strip. At each point of the photon space, the same picture is obtained from different points of view, and reflecting different points in time. that affect him at different points in their space. This is the main difference from the analogy with film strip. At each point of the photon space, the same picture is obtained from different points of view, and reflecting different points in time.

What happens when a photon moves? A wave runs through the entire chain of the photon space when it intersects with our space. The wave decays when it collides with an obstacle and transfers its energy to it. Perhaps the intersection of the photon space with our space creates the angular momentum of an elementary particle, also called the particle’s spin.

Now let's see what a photon looks like in our world. From the point of view of the observer, the photon space is folded into the dimensions of the photon itself. In fact, this is the most convoluted space and is the photon itself, vaguely reminiscent of a string. A string built from symmetrical projections of itself from different points in space and time. Accordingly, the photon contains all the information about itself. At any point in our space, he “knows” all the way, and all the events of the past and future, concerning the photon itself. I believe that a photon can certainly predict its future, you just need to put the right experiment.

### conclusions

**1.**There remain a lot of questions, the answers to which are difficult to obtain without conducting experiments. Despite the fact that such experiments with two slots were carried out many times, and with various modifications, it is very difficult to find information about this on the Internet. Even if you manage to find something, nowhere are there any meaningful explanations of what is happening and an analysis of the results of the experiment. Most of the descriptions do not contain any conclusions and boils down to the fact that “there is such a paradox and no one can explain it” or “if it seems to you that you understood something, then you did not understand anything”, etc. And meanwhile I consider That is a promising area of research.

**2.**What information can be transmitted from the future to the present? Obviously, we can convey two possible values when we will or will not observe idle photons. Accordingly, in the current time, we will observe wave interference or accumulation of particles from two bands. Having two possible meanings, you can use binary coding of information and transmit any information from the future. To do this, you need to properly automate this process, using a large number of quantum memory cells. In this case, we will be able to receive texts, photos, audio and video of everything that awaits us in the future. It will also be possible to receive advanced developments in the field of software products and it is even possible to teleport a person if you send instructions in advance on how to build a teleport.

**3.**You may notice that the reliability of the information received applies only to the photons themselves. Obviously false information can be sent from the future, leading us astray. For example, if you flipped a coin and the tails fell, but we sent information that the eagle had fallen, then we mislead ourselves. It can be reliably asserted only that the information sent and received does not contradict each other. But if we decide to mislead ourselves, then I think that over time we can find out why we decided to do this.

In addition, we cannot determine exactly from what time the information was received. For example, if we want to know what will happen in 10 years, then there is no guarantee that we sent the answer much earlier. Those. You can falsify the time of sending data. I think cryptography with public and private keys can help to solve this problem. To do this, you need an independent server that encrypts and decrypts data, and stores pairs of public-private keys generated for each day. The server can, upon request, encrypt and decrypt our data. But until we have access to the keys, we will not be able to falsify the time of sending and receiving data.

**4.**It would not be completely correct to consider the results of experiments only from the point of view of theory with respect to. At least due to the fact that the service station has a strong predetermination of the future. It is not pleasant to think that everything is predetermined by fate; I want to believe that each of us has a choice. And if there is a choice, then there must be alternative branches of reality. But what happens if we decide to act differently, contrary to what is displayed on the screen? A new loop will arise, where we also decide to act differently, and this will lead to the emergence of an infinite number of new loops with opposite solutions? But if there is an infinite number of loops, then initially we should have seen on the screen a mixture of interference and two bands. So, we initially could not decide on the opposite choice, which again leads us to the paradox ... I am inclined to think that if alternative realities exist, then only one option out of two possible will be displayed on the screen, regardless of whether we make this choice or not. If we make a different choice, we will create a new branch, where initially another option out of two possible will be shown on the screen. The possibility of making another choice would mean the existence of an alternative reality.

**5.**It is likely that once the experimental setup is turned on, the future will be predetermined. There is such a paradox that the installation itself determines the future. Can we break this ring of predestination, because everyone has freedom of choice? Or will our “freedom of choice” be subordinated to cunning predestination algorithms, and all our attempts to change something will eventually form a chain of events that will lead us to this predestination? For example, if we know the winning lottery number, then we have a chance to find this ticket and get a win. But if we also know the name of the winner, then we can no longer change anything. Maybe someone else should have won the lottery, but we determined the name of the winner and created a chain of events that led to the predicted person winning the lottery. It is difficult to answer these questions without conducting experimental experiments. But if this is the case, then the only way to avoid predestination is to see each other not to use this setting and not to look into the future.

Writing down these conclusions, I recall the events of the movie “The Hour of Reckoning”. It is striking how exactly the details of the film coincide with our calculations and conclusions. After all, we did not seek to get just such results, but simply wanted to understand what was happening and followed the formulas of Einstein's theory of relativity. And yet, if there is such a level of coincidence, then apparently we are not alone in our calculations. Perhaps similar conclusions have already been made decades ago ...