Physicists are increasingly noticing a paradoxical trend: sometimes proving the obvious is more difficult than proving the unbelievable. Here is another example taken from latest research. Matter is the basis of everything in the Universe, and this is obvious. Everything from your noisy neighbor to the farthest galaxy is material. However, the laws of physics require symmetry. For every negative charge there is a positive charge, and for every matter there is antimatter. So why don't we notice antiparticles around us, because they are formed in the same way as positively charged particles in the nuclei of active galaxies?
Astronomers say that it is almost impossible to see antimatter. A complete picture has not yet been formed on this score, and only assumptions are made. Not so long ago, an international team of physicists may have found a clue. Scientists have found that some atomic nuclei not symmetrical, but pear-shaped.
Nuclear theories have been debunked
The researchers looked at isotopes of barium. One of them, barium-144, is not a spherical or oval regular shape. This is the reason for the fragility of the atom, because the protons and neutrons inside it are distributed asymmetrically. Accordingly, a large mass is concentrated at one end of the nucleus, and a smaller one at the other. Curiously, this conclusion is in conflict with some nuclear theories. For example, until now, physicists have not been able to prove the obvious - the impossibility of time travel. However, now humanity has a unique opportunity to do so.
Violation of the principles of symmetry
Particles that are distributed inside the pear shape violate the principles of CP symmetry (where C is charge conjugation and P is parity). In C-symmetry, all differently charged particles behave in the same way. Thus, antihydrogen will behave like hydrogen. P-symmetry is oriented to space, where any system must have a mirror image.
CP symmetry suggests that for every particle moving counterclockwise, there is an anti-particle moving in the opposite direction. But if scientists manage to fully prove the violation of the laws of symmetry, this will explain the absence of antimatter. It is worth noting that so far only a few confirmations of this theory have been found. And now another refutation has been found. The discovered atom, which has an asymmetric shape, is another proof that not all laws of physics fit into standard model(a theoretical construction in elementary particle physics).
How to apply it to time
We know that the Universe is symmetrical with respect to CPT (charge, parity and time). But if conditions C and P are violated, then the symmetry of T will also be violated. This means only one thing: things cannot travel back in time. The detected asymmetric nuclei literally indicate the direction in space. Time cannot turn back, and every "passenger" in the universe has a one-way ticket.
There is probably no other topic in the world as exciting as time travel. For centuries, humanity has not only been interested in its meaning, etc., but also dreamed of a time machine. As a result, many famous science fiction writers have created incredibly interesting novels and stories about time travel, which have become real bestsellers.
But will we ever be able to create a time machine and travel to the future or the past? Is this possible in principle, or is it all the fruit of our imagination and the dreams of scientists and science fiction writers? Believe it or not, today we already know how to build a time machine. So now it's a matter of time - when we still create a real time machine and go to the distant future.
In September 2015, cosmonaut Gennady Padalka returned to Earth from his last, sixth spaceflight. On this day, he broke the world record for the time spent by a person outside earth's atmosphere. This astronaut has been in space for a total of 879 days. That's 2.5 years in orbit! During this time spent orbiting the Earth at great speed, cosmonaut Gennady Padalka became a real time traveler, once again testing the theory general relativity Einstein in action.
When Padalka's last time returned to Earth, he, in fact, was in the future. True, he was only 1/44 of a second in the future. That was how much faster time went for him for all 879 days spent in the orbit of the Earth, compared with the time for all of us who have been on Earth all this time. That is, in the literal sense, cosmonaut Gennady Padalka, during all his flights, traveled in time ... into the future.
As a result, our Russian cosmonaut turned out to be a fraction of a second younger than all those who have remained on Earth all this time. As you can see, such time travel turned out to be very simple and did not involve the use of charged plutonium in the DeLorean car that became famous after the release of the Back to the Future trilogy.
The secret of Gennady's journey through time is the high speed in the Earth's orbit, where time flows faster. In fact, if our cosmonaut had the opportunity to move in space for all 879 days at the speed of light, after landing on Earth, he would literally be in the future, since many years would have passed on Earth during this period.
That is, according to Einstein's theory of relativity, the higher your speed of movement, the slower time flows for you. Accordingly, if you move at near-light speed, not only time will slow down for you, but also all physical processes in the body. And when you return to Earth, you will find that in your absence, time on Earth has gone much forward, and your peers have aged noticeably.
As a result, since the discovery of Einstein, who determined that time in our Universe is relative (that is, time flows differently for each of us), humanity, in fact, has learned the main “ingredient” of traveling to the future. It's about about speed. So if you want to literally travel to the future today, all that's left to do is figure out how to accelerate to near-light speed.
How can you travel back in time scientifically?
Until the 20th century, it was believed that time is unchanging and that for each of us it flows the same way, that is, that it is absolutely in the entire universe. Accordingly, it was believed that time travel was impossible. In the 1680s, Isaac Newton began to think about the nature of time, establishing that time flows independently of external forces and your location. As a result, for many years the scientific community took as a basis all Newton's teachings about the motion of bodies and the flow of time.
But after two centuries scientific world expected a revolution in knowledge.
In 1905, the young scientist Albert Einstein developed special theory relativity, using his theory of general relativity as a basis. Einstein defined many new concepts related to time.
He found that time in the universe is elastic and depends on speed, slowing down or speeding up, depending on how fast an object or person is moving.
In 1971, an experiment was conducted that confirmed that time for us on Earth flows more slowly than for those who move above it at a faster speed. Moreover, the higher above the Earth we move at a greater speed, the faster time flows for us.
During this experiment, scientists sent four instruments with atomic clocks (cesium atomic clocks) into flight. This clock flew around the Earth. Next, the readings of the clock were compared with the same clock that was on Earth at that moment. As a result of the experiment, Einstein's theory was confirmed that time for objects or people flying at a speed above the Earth flows faster. So, as a result of comparing the clock readings, it turned out that the clock that flew around the Earth went nanoseconds ahead in comparison with the clock that was on the Earth during the experiment.
By the way, there is one interesting technology in your smartphones that also confirms Einstein's theory.
"WITHOUT EINSTEIN'S GENERAL THEORY OF RELATIVITY
OUR GPS/GLONASS SYSTEM WILL NOT WORK" .
We are talking about the satellite navigator (GPS, or GLONASS system) built into our phones, which, with the help of satellites orbiting the Earth, receives a signal about the location of our smartphone on the ground.
Indeed, due to the fact that satellites in orbit move at high speed and are far from the Earth, it turns out that time moves faster for them than for our smartphone located on Earth. As a result, it is periodically necessary to synchronize the time of navigation equipment on Earth and in the electronics used on satellites. Otherwise, the satellites would incorrectly determine our location.
By the way, in addition to the fact that time is relative for each of us, Einstein calculated the exact speed of light, which is 300,000,000 meters per second. Einstein also established that this is the speed limit in the universe. That is, according to Einstein's theory, nothing in the world can move faster speed Sveta.
The last idea of the great scientist and thinker was that gravity also slows down time. Einstein found that time runs faster where gravity is weaker. For example, on Earth, on the Sun and Jupiter, time passes more slowly than in open space, since these planets have a large force of gravity (gravity), which affects the course of time. Accordingly, the course of time, as you can see, is affected not only by the speed of the object in space, but also by the force of gravity.
For example, time at the top of Everest flows faster than time at its foot. If you take an atomic clock, one of which is placed at the top of the mountain, while the other is left lying at the foot, then exactly in a day the clock at the top will go nanoseconds ahead. That is, in fact, the clock on Mount Everest will travel into the future. True, for a very short time. This is possible due to the fact that the force of gravity at the top of the mountain will be weaker than at the foot.
Time machine of the subatomic world - Already a reality
But why was a Russian cosmonaut only 1/44 of a second in the future? The thing is that he moved in the orbit of the Earth for 879 days at a speed of 27,000 km / h. As you can see, compared to the speed of light at which time stops, the speed in Earth orbit is negligible to literally send an astronaut hundreds of years into the future. In fact, the astronaut made a jump into the future for a negligible amount of time.
Now let's see what happens if we create a spacecraft that can fly faster than the geostationary objects that orbit the Earth today. No, as you can see, we do not mean a commercial airliner capable of flying at a speed of 1000 km/h, or a rocket flying towards the ISS at a speed of 40,000 km/h. Let's think about an object that could accelerate to almost the speed of light, which is almost 300,000 km per second.
Do you think this is impossible in our nature? It turns out not. Of course, it is still very, very early to talk about some kind of large object that can be accelerated to near-light speed. But we have learned how to accelerate subatomic particles to the speed of light, literally sending them into the distant future. This is the most high-tech project of scientists from many countries in the history of mankind - the Large Hadron Collider, which can accelerate subatomic particles almost to the speed of light.
Believe it or not, this particle accelerator is capable of accelerating protons up to 99.999999% of the speed of light. At this speed, relative time moves about 6,900 times slower than their stationary observers.
"Large Hadron Collider... REGULARLY SENDS
SUBATOMIC PARTICLES TO THE FUTURE”.
So, yes, we have learned how to send atoms into the future. And scientists have been doing this for last decade quite successfully. But sending a person into the future is another matter.
But the most interesting thing is that, taking into account the fact that scientists have learned to regularly move particles at the speed of light, it is conceptually possible to send a person to travel into the future. The fact is that a person's journey into the future is really possible and is not prohibited by any law of physics.
In fact, in order to, for example, send a person to the year 3018, today it is enough to put him in a spaceship and accelerate the shuttle to 99.995 percent of the speed of light.
Let's assume that such a ship is created. So imagine you are boarding a similar supership that is going to a planet 500 light-years away (for example, the newly discovered Earth-like planet Kepler 186f, which is 500 light-years away). For those who do not know or do not remember, we recall that 500 light years is the distance that light will overcome in 500 years of its journey. Knowing the speed of light, you can calculate what an incredible distance at which the Kepler space telescope was able to detect a planet that resembles Earth in characteristics.
So, now let's imagine that you got into a spaceship that flies to the planet Kepler 186f. Then your ship accelerates to the speed of light and flies for 500 years, moving at almost the speed of light. Having approached the planet, your ship turns around and flies back to Earth for another 500 years at the same circumluminal speed.
As a result, the entire journey will take you 1000 years. When the ship returns to Earth, it will already be 3018.
But wait, how can you survive in this spaceship for 1000 years? After all, people can't live that long, can they?
This is where Einstein's theory of relativity comes in. The thing is that when you move 500 years (by earthly standards) towards a distant relative of the Earth at the speed of light, time will flow more slowly for you than for all the inhabitants of the planet.
So, when moving at near-light speed, your clock on the ship and all your processes in the body will slow down. For example, your clock on a spaceship will tick at 1/100th the speed of a clock on Earth. That is, having covered a distance of 500 light years and the same amount back, you will grow old only by 10 years, while on Earth 1000 years will pass during your journey.
But this is just a theory and our fantasies. Yes, as you can see, time travel is theoretically possible. It is real. Unfortunately, there is always a huge gap between theory and reality. After all, today we cannot build a spaceship that could accelerate almost to the speed of light. So how do we overcome the challenges of building a time machine?
Will humanity soon be able to build a ship capable of moving at the speed of light?
As you can see, in order to travel to the future, we need a spacecraft that can accelerate to near-light speed. Indeed, it is very difficult to do so. After all, there are huge engineering obstacles. Firstly, today mankind is still far from being able to build such a spacecraft capable of moving at the speed of light.
The fact is that today the fastest spacecraft ever created by mankind is solar probe "Parker", which will soon be launched into space. This space probe will be able to accelerate to a maximum speed of 450,000 miles per hour (724,204.8 km / h). Yes, it will be the fastest human-made object throughout its history. But compared to the speed of light, this speed is negligible. For example, at this speed, you could get from Philadelphia to Washington in just 1 second. But during this time, the light will cover the same distance 8 times.
Now imagine how much energy it takes to accelerate a spaceship to the speed of light. What then is the best fuel to use to generate incredible energy that could accelerate the ship to near-light speed?
Some scientists and astrophysicists suggest using spaceship highly efficient anti-matter fuel (anti-matter fuel). By the way, many scientists of the world believe that such fuel could indeed be potentially invaluable in interstellar travel.
But beyond fuel, there is an even bigger problem for interstellar travel. It is about the safety of people who will travel at the speed of light. After all, such a spacecraft will have to carry a sufficient amount of supplies for the crew members who went on an interstellar journey (food, water, medicines, etc.). But in order to provide a long journey in space, the ship must be large enough. As a result, the larger the ship, the more energy it will need to accelerate to the speed of light.
Including when accelerating to the speed of light, it must be taken into account that the acceleration must be smooth, because otherwise the people on the spacecraft will receive too much overload during acceleration, which is life-threatening.
But then, to accelerate the ship to near-light speed, it will take too much time. Indeed, in fact, the ship can be slowly accelerated, adding a little speed so that the overload experienced by the ship's crew for a long time does not exceed 1g (usually, being on Earth, we experience this overload).
Thus, in order to accelerate to the speed of light, it may take too long a period, which will significantly increase the travel time. And this ultimately minimizes the possible travel time to the future.
For example, using our example of a 500 light-year journey with smooth acceleration, resulting in no more than 1 g of g-force, our flight time on a spaceship will take not 10 years, but already 24 years. But nevertheless, when traveling at near-light speed for a distance of 500 light years and back, you can still get to 3018.
Unfortunately, to create such an incredible space vehicle with similar specifications, humanity will still need a lot of time, resources and, of course, a lot, a lot of money. But the same can be said about other large-scale ambitious projects that seemed impossible just a few decades ago. We mean a project to detect gravitational waves and large collider Hadera. Today, these projects are already a reality and surprise no one.
So who knows what awaits us in the coming decades. After all, it is quite possible that the next scientific megaproject will be the creation of a time machine (a spacecraft capable of accelerating to the speed of light).
Is it possible to travel back to the past?
But in the time machine we have described, which may someday become a reality, travel to the future takes place in real time. That is, if you sit in a spaceship today and accelerate to the speed of light, the time of your clock and the clock of people on Earth will go in reality. The only difference will be that your clock will slow down while traveling.
As a result, the spaceship representing the time machine, in fact, throws you into the future in real time, but not in reverse. That is, on such a spaceship you will not be able to travel to the past. But is it even theoretically possible to time travel to the past?
Some scientists believe (not all, for example, Hawking proved that it is impossible to travel into the past), that travel to the past is also possible. But for this you need to find a place where you can bypass the laws of physics.
The most interesting thing is that such places in the universe can be.
For example, purely theoretically, travel to the past is possible through a wormhole (wormhole norm in space-time), through which one can get into the past.
The problem is different - to find in space a similar place where there is a wormhole connecting the fault in space-time. Unfortunately, in most cases, such burrows disappear within nanoseconds after their appearance.
Meanwhile, according to Einstein's theory of relativity, such wormholes are real. The fact is that such wormholes can form as tunnels crossing through curved space-time. Theoretically, through such holes, you can send a beam of light to a certain point in space. Accordingly, theoretically, a beam of light can be sent into the past.
Fiction? Not at all. Look at the sky at night and you will see the light of thousands of stars that has reached your eyes only today, despite the fact that many stars ceased to exist billions of years ago. The thing is that these stars are at a great distance from us, and also, given that our Universe is constantly expanding, it turns out that the light of many stars came to us from the past.
Thus, as you can see, theoretically sending someone into the future is much more real than into the past. Therefore, in the future, most likely, scientists will first of all be ready to send someone to the future, and not to the past. Unfortunately, this will not happen in the near future. After all, for this humanity will still need to come up with a superfuel capable of accelerating the ship to near-light speed.
Nevertheless, as you can see, the journey into the future is real and possible. But this requires huge funding. According to many scientists, if today many states united and financed a project to create a spacecraft capable of moving at the speed of light, then in 20 years such a ship would become a reality.
In the meantime, in order to enjoy the effect of a time machine, we can only review famous films about time travel, as well as re-read various popular science fiction books.
Moreover, many films really show what it can look like. space trip in time. For example, watch the old original movie "Planet of the Apes" where the astronauts thought they were on another planet similar to Earth, which is controlled by monkeys instead of people.
But in fact, the astronauts arrived on the same planet Earth in the future, where, for some reason, monkeys seized power on the planet. In fact, in this film, the astronauts arrived in the future of planet Earth, as their journey through space was carried out at the speed of light. This movie accurately portrays Einstein's special theory of relativity and shows how a person can travel to the future.
The theme of moving into the past time excites the minds. But is a return possible? Imagine that a person nevertheless returned to his recent past, knowing that his parents committed a very vile act towards him, and he killed them, being in the past tense. And who would then conceive and give birth to this person? The act of taking the life of parents by their child would violate the logic of events and would not lead to a picture of the present. Consequently, we get an extremely serious doubt about the possibility of traveling into the past. We can only be partially consoled by the hypothesis of the existence new reality in a parallel universe, not ours according to .
Well, some hypotheses are allowed physicists that time travel might be possible, as long as it doesn't change the future. After all, even minimal changes can change the course of history, this is the cornerstone credo of the study of chaos, where "a small cause makes a big impact."
Let's turn to perhaps the most venerable scientist of our time, Stephen Hawking, regarding the concept of the universe. To avoid the paradoxes of time, he suggested that there was in fact a law of nature that is called to "protect the temporal order" that prevents closed, time-like curves from appearing. In particular, the scientist exclaims: “Where are the tourists from the future, if time travel is possible?”
A serious attempt to create the concept of the possibility of time travel appeared in the middle of the 20th century after the emergence of the wormhole theory, which is schematically illustrated in the figure (from the site myjulia.ru), as well as in the film Dark (Darkness). In this picture in a small town, young people disappear without a clear explanation. However, it soon becomes clear that the missing young people make their way through the "wormhole" into the past, and become time travelers.
A wormhole is a tunnel between temporary worlds, and in the film the tunnel is hidden in a cave, and draws energy to move from nuclear power plant, which is located at the bottom of the cliff. Time travelers find themselves in the past literally behind iron doors, come into conflict with their ancestors, and at times even with ... themselves. Thus, the logical timeline of events is violated, which causes a large number of questions like those above.
One of their main claims for the relativity-based space-time picture of tunnels is that celestial bodies bend the space around them, and all other bodies, as well as light, must follow these spatial dents. As an illustration, our three-dimensional space reduced to two dimensions. Away from everything - space is not curved, respectively, the two-dimensional simplification is flat, like a fabric. If we put a ball, which is heavenly body, on this fabric, a void will be created around it. So it is possible to imagine a curved space.
And now, unknown to the public, Ludwig Flamm from the University of Vienna suggested the possibility of connecting two curved spaces with a tunnel, then A. Einstein and Nathan Rosen announced the possibility of a “bridge” between two spatial zones, the connection of which can be associated with particles or energy. Such an Einstein-Rosen bridge would be an acronym for a hypothetical four-dimensional hyperspace. Finally, in the 1950s, American relativity pioneer John Archibald Wheeler learned that such a bridge might be possible and coined the term "wormhole". It's like for a worm to get from one side of an apple to the other through a gnawed tunnel. This is how people got the idea of traveling to other stars: instead of flying thousands of years to the next star, you can quickly get to it through a wormhole. But this wormhole hypothetically allows you to travel in time, since time in the tunnel flows differently than in our usual environment of existence. At the edge of a tunnel, a black hole, even time can stop.
But any action needs energy. To go through the tunnel you need special kind negative substance or better negative energy opening a hole. It is impossible to imagine how it is possible to generate negative energy in such a high density. In the film, it arises from an accident at a nuclear power plant (in the film, a casus is admitted - the action returns travelers to 1953, when there was no nuclear power plant yet).
But even these wormholes would be unstable, as they disappear again in a fraction of a second. How to keep such a tunnel open has been studied by many theoretical physicists without any tangible results. “I doubt that the laws of physics allow permeable wormholes,” says physicist Thorne. Without a far-reaching theory that unifies the laws of relativity and quantum physics, which also play a role, this topic is likely to continue to be speculation.
So, returning or traveling to the past is hardly possible in reality. In any case, within the limits of our understanding of the universe.
“The difference between past, present and future is an illusion, albeit a very stubborn one,” A. Einstein argued. This thesis became, in a sense, the motto of the film, the presentation of the plots from which we used to understand the possibilities of moving in time.
However, the topic of time travel gives a lot of thought, and physicists have already published hundreds of papers about it. Einstein would probably banish them entirely to the realm of fantasy, because he firmly believed in the irreversible order of cause and effect.
Add the article to your bookmarks to return to it again by clicking the buttons Ctrl+D . Subscribing to notifications about the publication of new articles can be done through the "Subscribe to this site" form in the side column of the page.
The paradoxes of time travel regularly occupy the minds of not only scientists who comprehend possible consequences such a movement (albeit hypothetical), but also people who are completely far from science. Surely you have argued with your friends more than once about what will happen if you see yourself in the past - like many science fiction authors, writers and directors. A movie with Ethan Hawke just came out today leading role"Time Patrol" according to the story of one of the best science fiction writers of all times by Robert Heinlein. This year has already been a success of several films relating to the theme of time like "Interstellar" or "Edge of Tomorrow". We decided to speculate what potential dangers might await the heroes of temporary sci-fi, from killing their predecessors to splitting reality.
Text: Ivan Sorokin
Paradox of the dead grandfather
The most common, and at the same time the most understandable of the paradoxes that overtake the time traveler. The answer to the question “what will happen if you kill your own grandfather (father, mother, etc.) in the past?” may sound different - the most popular outcome is the occurrence of a parallel time sequence, erasing the culprit from history. In any case, for the temponaut himself (this word, by analogy with "astronaut" and "astronaut", sometimes refers to the pilot of the time machine), this does not bode well at all.
Movie example: The whole story about teenager Marty McFly, who accidentally travels to 1955, is built on preventing an analogue of this paradox. Having accidentally conquered his own mother, Marty begins to literally disappear - first from photographs, and then from tangible reality. There are many reasons why the first film in the Back to the Future trilogy can be considered an absolute classic, but one of them is how neatly the script sidesteps the idea of potential incest. Of course, in terms of the scale of the idea, this example can hardly be compared with the well-known plot from Futurama, as a result of which Fry still becomes his own grandfather, accidentally destroying the one who was supposed to become this grandfather; in the end, this event had consequences that literally affected the entire universe of the animated series.
Pulling yourself by your hair
The second most common time travel plot in cinema: going to a glorious past from a terrible future and trying to change it, the hero ends up causing his own (or everyone's) troubles. Something similar can happen in a positive context: the fairy-tale assistant who directs the plot turns out to be the hero himself, who came from the future and ensures the correct course of events. This logic of the development of what is happening can hardly be called a paradox: the so-called time loop is closed here and everything happens exactly as it should, but in the context of the interaction of cause and effect, the human brain still cannot but perceive this situation as paradoxical. This technique is named, as you might guess, in honor of Baron Munchausen, who pulls himself out of the swamp.
Movie example: The space epic "Interstellar" (beware, spoiler) uses a huge number of plot twists varying degrees predictability, but the emergence of a "closed loop" is almost the main twist: Christopher Nolan's humanistic message that love is stronger than gravity does not take its final form until the very end of the film, when it turns out that the spirit of the bookshelf protecting the astrophysicist played by Jessica Chastain , was the hero Matthew McConaughey, sending messages to the past from the bowels of a black hole.
The Bill Murray Paradox
Plots about looped time loops have already become a separate subgenre of sci-fi about temponauts for some time - both in literature and in cinema. It is not surprising that almost any such work is automatically compared to Groundhog Day, which over the years has come to be seen not only as a parable of existential despair and the desire to appreciate life, but also as an amusing exploration of the possibilities of behavior and self-development in extremely limited conditions. The main paradox here lies not in the presence of a loop itself (the nature of this process is not always touched upon in such plots), but in the temponaut’s incredible memory (it is she who is able to provide any movement of the plot) and the equally incredible inertness of those around him to all the evidence. that the protagonist's position is truly unique.
Movie example: Detractors have dubbed "Edge of Tomorrow" something like "Groundhog Day with aliens," but in fact the script for one of the best science fiction films of the year (which, by the way, was super-successful for this genre) handles its loops much more delicately. The paradox of perfect memory is circumvented here by the fact that main character writes and thinks through his moves, interacting with other characters, and the problem of empathy is solved due to the fact that there is another character in the film who at some point had similar skills. By the way, the occurrence of a loop is also explained here.
Deceived expectations
The problem of not meeting expectations is always present in our lives - but in the case of time travel, it can hurt especially badly. Usually this plot device is used as an embodiment of the proverb "Be careful what you wish for" and works according to Murphy's laws: if events can develop in the worst possible way, then everything will happen. Since it is difficult to assume that a time traveler is able to predict in advance what the tree of possible outcomes of his or her actions will look like, the viewer rarely doubts the plausibility of such plots.
Movie example: One of the saddest scenes in the recent rom-com "Future Boyfriend" looks like this: Domhnall Gleason's temponaut tries to go back in time to the time before the birth of his child and ends up coming home to a complete stranger. This is corrected, but as a result of such a collision, the hero realizes that more restrictions are imposed on his movements along the temporary arrow than he thought before.
Aristotle with smartphone
This paradox presents special case the popular sci-fi trope "advanced technology in a backward world" - only the "world" here is not another planet, but our own past. It is not difficult to guess what the introduction of a conditional pistol into the world of conditional batons is fraught with: the deification of aliens from the future, destructive violence, a change in the way of life in a particular community, and the like.
Movie example: Certainly the most a prime example The Terminator franchise should serve as a detrimental influence of such an invasion: it is the appearance of androids in the USA in the 1980s that ultimately leads to the emergence of artificial intelligence Skynet, which literally destroys humanity. Moreover, the main reason for the creation of Skynet is given by the protagonists Kyle Reese and Sarah Connor, due to the actions of which the main Terminator chip falls into the hands of Cyberdyne, from the depths of which Skynet eventually emerges.
The hard part of remembering
What happens to the temponaut's memory when, as a result of his own actions, the temporary arrow itself changes? The gigantic stress that must inevitably arise in such a case is often ignored by science fiction authors, but the ambiguity of the hero's position cannot be ignored. Well, there are a lot of questions here (and all of them do not have an unambiguous answer - to adequately check the answers to them, you need to literally get a time machine in your hands): does the temponaut remember all events or only part of them? Do two parallel universes coexist in the temponaut's memory? Does he perceive his changed friends and relatives as different people? What happens if you tell people from the new timeline in detail about their counterparts in the previous timeline?
Movie example: There is at least one example of such a state in almost every time travel movie; from a recent one, Wolverine from the last series of X-Men immediately comes to mind. The idea that as a result of the success of the operation, Hugh Jackman's character will be the only one who can remember the original (extremely gloomy) course of events, is voiced several times in the film; in the end, Wolverine is so happy to see all his friends again that memories that can hurt even a person with an adamantium skeleton fade into the background.
scary you #2
Neuroscientists are quite actively studying how people perceive their appearance; an important aspect of this is the reaction to twins and twins. Typically, such meetings are characterized by an increased level of anxiety, which is not surprising: the brain ceases to adequately perceive the position in space and begins to confuse external and internal signals. Now imagine how a person must feel, seeing himself - but of a different age.
Movie example: The interaction of the protagonist with himself is perfectly played out in Rian Johnson's film Looper, where the young Joseph Simmons is played by Joseph Gordon-Levitt in cunning makeup, and the elderly, who arrived from the near future, is played by Bruce Willis. Cognitive discomfort and the inability to establish normal contact is one of the important themes of the picture.
Unfulfilled predictions
Your opinion about whether such events are paradoxical depends directly on whether you personally adhere to a deterministic model of the universe. If there is no free will as such, then a skilled temponaut can safely bet huge amounts of money on various sports competitions, predict the results of elections and award ceremonies, invest in shares of the right companies, solve crimes, and so on. If, as is usually the case in films about time travel, the actions of the temponaut are still able to change the future, then the function and role of predictions based on a kind of insight from a stranger from the future are as ambiguous as in the case of those predictions that are based solely on on logic and past experience (that is, similar to those that are used now).
Movie example: Despite the fact that only "mental" time travel appears in "Minority Report", the plot of this film serves as a vivid illustration for both models of the universe: both deterministic and free will. The plot revolves around the prediction of yet uncommitted crimes with the help of "clairvoyants" who are able to visualize the intentions of potential killers (a situation of extreme determinism). Toward the end of the film, it turns out that visions are still able to change in time - accordingly, a person to some extent determines his own fate.
I was yesterday into tomorrow
In most of the world's major languages, there are multiple tenses for events in the past, present, and future. But what about the temponaut, who yesterday could observe the death of the Sun, and today he is already in the company of dinosaurs? What tenses to use in speech and writing? In Russian, English, Japanese and many other languages, there is simply no such functionality - and you have to get out in such a way that something comical inevitably happens.
Movie example: Doctor Who, of course, belongs to the field of television, not cinema (although several television films can be found in the list of works related to the franchise), but the series cannot be left out here. The Doctor's confusing use of different times became a cause for bullying back in pre-Internet times, and after the revival of the series in the mid-2000s, the authors decided to deliberately emphasize this detail: now the on-screen Doctor is able to connect his non-linear perception of time with the peculiarities of the language (and at the same time laugh at the resulting phrases) .
multiverse
The most fundamental paradox of time travel is not for nothing that it is directly related to a serious conceptual discussion in quantum mechanics based on the acceptance or rejection of the concept of "multiverse" (that is, the totality of multiple universes). What actually needs to happen the moment you "change the future"? Do you remain yourself - or do you become a copy of yourself in a different timeline (and, accordingly, in a different universe)? Do all the timelines co-exist in parallel so that you just jump from one to the other? If the number of decisions that change the course of events is infinite, then is the number of parallel universes? Does this mean that the multiverse is infinite in size?
Movie example: The idea of multiple parallel timelines is usually not adequately portrayed in films for one simple reason: writers and directors become afraid that no one will understand them. But Shane Carratt, the author of The Detonator, is not like that: to understand the plot of this film, where one non-linearity is superimposed on another, and to fully explain the movements of the characters in time, it is necessary to draw a diagram of the multiverse with intersecting timelines, it is possible only after considerable effort.
We continue the section about thoughts "that interfere with sleep." Sometimes before going to bed the brain is visited by a global heresy :) An attempt to briefly state logically with a technical approach to the problem.
The problem of time travel is complicated by the fact that it is necessary to send an object not only in time, but also in space. This requires precise coordinates in the universe. Let us hope that there is no need to calculate the position of the universe itself in a more global space...
To obtain coordinates on planet Earth at a different time, a large number of "nodes" of coordinates are needed:
- The rotation of the planet itself. Moreover, the center of rotation of the Earth does not coincide with the center of the planet itself, but is the center of the Earth-Moon system. From which it follows that this parameter constantly walks in space.
- Rotation around a star. Here everything is already more complicated than in the previous case. It is necessary to correctly calculate the center of the entire solar system, with all its planets and other flying "garbage".
- Rotation of the solar system in the galaxy. There are much more variables :) This is aggravated by the fact that solar system itself does not rotate in the plane of the galaxy.
- The expansion of the universe. Where is its center? Further, we move in a cluster of galaxies, which also interact with each other. In short, here it is already necessary to take into account the entire complex structure of the Universe.
But the difficulties continue: all speeds are not constants. Some of them are guaranteed to speed up, while others slow down. Moreover, this does not happen linearly, but with episodic (at different times) corrections for the interaction of all "objects" with each other, including those not taken into account on this moment time. The same applies to motion vectors.
If you trace the path of a certain point on the planet Earth in the required coordinate system, with all its rotations and movements, then at first glance it will look like " Brownian motion". The sum of all errors will be very large (at such and such speeds). If you try to send an object to the same place, but 10 minutes ago, it will turn out to be a disappointing result. The exit point is guaranteed to be either in space or underground. Or inside of some object, for example, in the wall of a building. But if you can still somehow calculate the coordinates in the past (with the availability of technology), then in the future it is impossible in principle. Here you need to know in advance the events that caused changes (corrections) in the entire system .
But, if you believe what is written, then unconscious jumps happen ... Perhaps this happens when magnetic anomalies occur with (ideally) the same parameters. That is, they form a "corridor" with a probability of triggering 50/50, "but this is not accurate" :) Otherwise, there would be much more messages, since there are quite a lot of anomalies.
So you can create something like a "navigation log" in which you can register all the anomalies and their parameters. Then you can generate a "twin" and try to move along the "corridor". You can generate your own exit points in the past, such as the "Philadelphia Experiment" (if there was one) or the Edison Tower at the time of activation. But even here surprises are possible... The "Journal" will cover a short period of time. And where is the guarantee that there were no such "points" outside of it (in the past and in the future)? So you can jump only at your own peril and risk ...
Returning back is also very difficult to implement, since the "corridor" has worked, and now it is in the past relative to the object. To return, you need to organize a new pair of entry-exit points. Although ... you can pre-plan a new exit point back to the future, but in this case, you have to fly into the past in a full-fledged time machine. But, .. if there are undocumented points in the pair (new corridor), then with each unsuccessful jump back to the future, in the past (of the traveler), another exit point will appear. Accordingly, to reach the return point, you may have to jump many times, generating a string of identical anomalies, reducing the chance to return to the original point in time.
But the main danger is that the "corridor" works equally well in both directions. What will visit us from there, one can only guess.
