Could time travel become a reality?

Travelling through time to visit the past or the future is one of the most explored philosophical and scientific questions. The theme arouses so much curiosity that it has been the subject of several cinematographic productions. We have gathered the main theories that, together with the plot of some films, will help us understand the subject and discover if it ever could become a reality.

Time dilation is a physical phenomenon explained by one of the best-known scientists in the world, Albert Einstein, creator of the Theory of Relativity, at the beginning of the 20th century.

The theory proposes that the time interval marked by a stationary observer is greater than the one in motion. In practice, temporal dilation makes the clock's hands "turn more slowly", as if the duration of the second, for example, suffered a slight increase.

Although there is still no known evidence that it is possible to travel through time physically, many theories and hypotheses have been proposed about this possibility.

The widely known concept has been addressed both in theoretical physics and science fiction, but few know how the physics behind this idea might work.

In general, the laws of physics do not allow for the possibility of going back in time to change the past.

According to physics as we currently understand it, if that were possible, we could, for example, kill our parents, which necessarily generates a paradox. So, in theory, the past cannot be changed, and the future is determined by the present.

However, there are some theoretical models in physics that suggest the possibility of time travel under certain conditions, such as the existence of the "wormhole", for example.

This hypothesis was explored in the film 'Interstellar' (2014), directed by Christopher Nolan (pictured) and starring Matthew McConaughey, Anne Hathaway and Jessica Chastain.

In the feature, Anne Hathaway (pictured) plays the chief scientist of the expedition, which sends a ship through a wormhole, in an experiment never performed before. The characters use this element to travel to different points in time and space in an attempt to find a way to save humanity from a catastrophic event.

On the distant planet where they arrive, the passage of time is much slower. Thus, those on Earth appear to age at a much faster rate, giving the illusion of traveling into the future.

Photo: Unsplash/Markus Spiske

The film explores the idea of the passage of time from a scientific point of view and also from a philosophical perspective, as it deals with the importance of time in shaping the human experience.

A wormhole is a structure in the form of a tunnel, a hypothetical passage through space-time, which would allow matter to travel from one point to another in the universe, bypassing the distance and time that would be required for the same trip in normal space. .

The concept of "wormhole" was proposed, for the first time, by the physicist Ludwig Flamm, in 1916, starting from Einstein's equations, from the General Theory of Relativity.

But it wasn't until the publication of a paper by physicist John Archibald Wheeler (pictured on the right) in 1955 that the term "wormhole" was coined.

Since then, several theories have been proposed, but there is still no empirical evidence to support the existence of these hypothetical structures.

In this film, the main character, Marty McFly, travels through time with the help of a machine, built into the iconic DeLorean car. Launched in 1985, it aroused the public's interest in scientific themes related to time.

In the film, the time machine is powered by a device called a "flux capacitor", which is activated when the car reaches speeds of 140 kilometers per hour (88 MPH), or faster. When the flux capacitor is activated, it creates a time shift, through its speed, which allows Marty to travel into the past.

As UOL published, "according to the theory of relativity, if it were possible to travel above the speed of light, we would go back in time, as Marty McFly did in the film. The problem is that there is not enough energy to make something exceed the speed of light. light". So the possibility of circumventing space-time would be possible in theory, but not in practice.

'Doctor Who' is a British science fiction series (pictured), released in 1963. The plot features an alien, called Doctor, who travels through time with a device called TARDIS  (Time and Relative Dimension in Space) and faces numerous enemies, while working to save civilizations and help the common people.

The series explores the consequences of altering the timeline and the importance of preserving the integrity of history. The Doctor is a complex and nuanced character who is often torn between the desire to right some wrongs and the need to avoid unintended consequences by altering the past.

The first film in the science fiction franchise tells the story of a cyborg assassin who travels back in time to kill Sarah Connor, a young pregnant woman whose child will lead the human resistance against an artificial intelligence called Skynet in the future.

In addition to being an iconic franchise, the films utilize time travel as a way to explore the possibility of going back to the past to change the future and the course of history. Thus, it raises questions about determinism and free will, and the ways in which our choices can have effects on the world around us.

'The Time Machine', by writer HG Wells, is considered the first science fiction novel to address the theme of time travel.

In this account, published in 1895, a traveler goes to the future and glimpses a tragic society divided into two factions: the idle and peaceful, Eloi, and the barbarians and predators, Morlocks.

As the character travels into the future, he encounters strange and fantasy societies and landscapes, and is forced to reflect on the passage of time and his role in the universe.

Ultimately, the book raises thought-provoking questions about the progress of nature, the importance of history, and the impact of technological advancement on society.