Ask Ethan: which films correctly show time travel?
Train "Jules Verne" from the third part "Back to the Future". Perhaps Einstein did not imagine this at all when he formulated his mental experiments related to the theory of relativity, but the degree of scientific can still be estimated.
The way we travel in time, at a rate of one second per second, is so boring that we take it for granted. However, according to Einstein's theory of relativity, we can travel in time not only with different speeds (if we increase the speed to values close to the speed of light), but also in different directions, forward or backward, constructing a bridge between two unconnected places of space -time. Traveling in time, forwards or backwards, has long been one of the leitmotifs for our imagination and stories; who would not want to learn an unknown future or go back in time to correct past mistakes? However, it is a completely different task to compose a correctly correct story from a scientific point of view. What films have coped with this best? This is what our reader wants to know:
I am a big fan of films about time travel (no matter how they are explained). Which of the films use this story tool better and more accurately?
Let's think about what should be in a good movie about time travel, and how your favorite movies are treated.
Relativistic journey to the constellation of Orion. The closer you come to the speed of light, the more distorted the visible space and reduces the apparent distance to the stars, and the less time passes during your journey. To obtain illustrations, the program
was used. StarStrider , a relativistic planetarium from FMJ-Software.
If you are striving for scientific correspondence, you need to understand how the journey in time looks. One of the most revolutionary ideas of Einstein's theory of relativity was that space and time are inseparable from each other. The universe consists of a four-dimensional space-time fabric, and all objects, particles and radiation exist against its background. This leads to a strange and not intuitive phenomenon: your movement through time is influenced by your movement through space, and vice versa.
Light clocks will go differently for observers moving at different speeds, due to the constancy of the speed of light. SRT Einstein talks about how to convert these times and distances.
Any object existing in space-time will immediately notice the following three things:
For other objects moving relative to it, the distances will decrease, and the time will lengthen.
Relatively to them, light always moves with the same speed c, the speed of light in a vacuum.
Their movement through space-time is determined by the curvature of space-time, which depends on the surrounding matter and energy.
If you are in a certain frame of reference (for example, standing motionless on the surface of the Earth), then everyone who moves relative to you will travel a greater distance in space, and therefore less in time.
Movement with a speed close to the speed of light will lead to the fact that time will flow in different ways for the moving person and for the person remaining in the fixed frame of reference.
Therefore the paradox of twins works like this: one who left the Earth and moves at a speed close to the speed of light, will age less than than his identical twin, left on Earth. One who moves through space at a greater speed will experience slow motion through time. If we start taking into account the General Theory of Relativity, and the effects of gravity, staying in a strong gravitational field will have a similar effect on you: you will feel the course of time as normal, but those who are away from you will grow old much faster. This effect is most pronounced near the singularity of the black hole, after you have passed through the event horizon.
Mathematical diagram of the Lorentz wormhole. If one of its end is created from a positive mass-energy, and the other from a negative one, then the wormhole can become passable.
But in the UTO there is another interesting possibility: the appearance of wormholes. Wormholes are most often perceived as a short path in space, but there is no reason for them to go only through space; just like space and time will do! You can use it if you can create, stabilize and pass (or send information) through it, and go forward or back for an arbitrary amount of time. You can even create loops, or closed timelike curves , admissible mathematical solutions that exist under certain conditions.
For example, in the context of general relativity one can go back in time to a certain place; you only need to make a certain adjustment.
Warp engine , depicted for NASA. If you create a wormhole between two points in space, with one input moving at a relativistic speed relative to the other, the observers at both ends will age at very different speeds.
If you create a massive black hole from matter, and then another black hole from the negative mass (which should theoretically exist), you can create a wormhole between them. Dilute them at any distance and accelerate one of the ends of the wormhole to a speed close to light. And while you are moving along with the accelerated end, you can go through it at any time, and be on the other side of the wormhole unharmed. And most importantly, since you moved at a speed close to light, for you time went differently. When you move in the opposite direction, it turns out that at home almost nothing has changed. You can travel hundreds of years, and then return to the point of departure a few seconds after you left it. In this sense, a journey back in time is quite possible physically.
Is it possible to travel in time? With a fairly large wormhole, for example, created with the help of a supermassive black hole, connected with its counterpart, consisting of negative mass-energy, is complete.
There are many opportunities, as many films, taking advantage of the combination of time machine and creative narrative. Of course, there are many films, in this sense, saving on scientific certainty.
Hardly anyone remembers the films "Timecop", "Hot Tub Time Machine", or "Bill & Ted's Excellent Adventure" for the incredibly accurate description of time travel with the help of time machines. In the film "Idiokratiya" time travel is used in the sense that time passes, and objects and people remain unchanged. Superman takes the time back to save the life of Lois Lane in the original Superman movie, but it was not science, it was super-powers. The same can be said about the recent film about Dr. Strange or the cult Warlock, or about the film "Harry Potter and the Prisoner of Azkaban"; The use of magic for the movement in time of scientific points you will not add. In many films, time travel is predominantly used as a plot move, without regard for scientific certainty. Even in the film "Army of Darkness", although it is funny, there is no reliable mechanism for moving around the story in time.
Reading the spell from the Necronomicon and transferring to the past - this plot is suitable for an entertaining movie, but scientific verification does not work.
But some films, although they do not tell, and do not directly show the mechanism of moving through time, wonderfully accurately describe what a time travel might look like. Moving forward is quite simple: you need to approach the speed of light, return to the start point, and you are in the distant future. That's how on the "Planet of the Apes" sent a man into the distant future on the anti-utopian Earth, and therefore "Star Wars" is so annoying with its "hyperdrive". Rapid movement has a serious impact on the speed of the passage of time, and carries you to the future no matter what you do.
Hyperdrive from the "Star Wars", apparently, depicts a relativistic motion in space, close to the speed of light. But no one grows old at a speed different from normal, and this violates the principles of relativity.
Return to the past, especially at a certain moment - the basis of the stories in the films about time travel. There are two theories about the operation of this mechanism:
The flow of time is invariable; everything that happened has already been recorded, and when you move back, you can not change the course of events. Your move is already built into the course of events.
The time scale can be changed; The changes you make when going back, lead to the appearance of another future, perhaps even rejecting your existence.
Two excellent examples of the first theory are "Twelve Monkeys" and "The Loop of Time", where the future is already recorded. Moving in time allows you to live and interact with the past, but does not change the course of history. Events that unfolded so that you went back in time, have already occurred. You just live your life, knowing the destiny of the world perfectly.
The idea of moving to the past has long occupied people - for example, with the help of Delorean DMC-12 from "Back to the Future". After decades of research, we may have stumbled upon a physically possible solution, but for him, Delorean, most likely, will not be needed.
On the other hand, there is the possibility that your future is not recorded, even if you yourself have come from the future. In the series "Back to the Future" and the films "Terminator" 1 and 2 on this much is built. Although they describe how time travel works physically, omitting some key ingredients, the actions of travelers can change the future. Kyle Reese and Sarah Connor can prevent or postpone the day of judgment by battling a terminator sent to the past to kill or prevent the very existence of the boy who will fight the machines. Marty McFly travels in time to save his friend's life, but he needs to see to it that in the process he does not erase himself from the history. These are two of the best examples of films with a changing future. Also with this, the films from the series "Star Trek" - the film of 200? "The First Contact" and "The Way Home" are doing well.
The best black hole was shown in the film "Interstellar", and it quite accurately depicts the horizon of events for a very specific class of rotating black holes. In the depth of the gravity well, the time for the observer is not the same as outside.
Two films are distinguished by scientific certainty and level of detail: Interstellar and Contact. Interestingly, the consultant for both films was the same scientist, Kip Thorne, and they both use the idea of black holes and wormholes. In the depth of the gravitational well of the black hole in the "Interstellar" time for the observer goes with a different speed, which leads to a relativistic turn of the plot. In the movie "Contact", a moment on Earth corresponded to an almost all-day tour of the Galaxy, and potentially throughout the entire universe. The physics of black holes, wormholes and OTO in these films appear in all its glory, and they look pretty picturesque.
Bill Murray drinks a coffee pot in front of Andy McDowell in one of the scenes of the movie "Groundhog Day"
Finally, there is another, probably the most realistic and interesting film that uses time travel as a "time loop": "Groundhog Day". Any solution of general relativity that allows to exist as a closed timelike curve is usually rejected because of philosophical concepts like " grandfather's paradox " But these mathematical solutions are consistent and can describe reality, especially if we assume that the beginning of the loop "nullifies" the state of the system . In "Groundhog Day," this moment is perfectly used, and the temporary loop is destroyed only when a sufficient number of changes accumulate in this ridiculous, moral fairy tale about good and self-determination. Although it lacks scientific character, the image of the time loop is done here in the best way (although I have not yet seen the "Face of the Future").
Here are the films, of those that I saw, correctly describing time travel from a scientific point of view.