By Uğur Güven
Have you ever dreamed of travelling through time like characters in science fiction films? This idea has been stirring people’s imagination for centuries. Imagine that you could go back in time and see how people lived in ancient times, or travel to the future and find out what our world will be like in the future. Imagine that you could go back in time and visit your deceased relatives, parents who are no longer alive. It would definitely be a very interesting and emotional experience.
Time travel is a concept that refers to travelling between different points in time, like moving from one place to another. Science fiction has already approached this problem in various ways. But here’s the question: is it nothing more than a fun idea for films or a real possibility?
Scientists still haven’t solved the mystery of whether time can be turned back. It’s unlikely if the universe obeys the laws of thermodynamics. The second law of thermodynamics states that things in the universe can either stay the same or become increasingly disordered over time. Just as eggs once cooked can no longer be “harvested” in their raw form.
According to this law, the universe can never fully return to its previous state. Time can only move forward by analogy with a one-way road. One of the world’s most serious time travel researchers is University of Connecticut professor Ronald Mallett. This respected astrophysicist’s obsession with time travel and its equations goes back to his childhood. Professor Mallett was ten years old when his father, a TV repairman, died suddenly of a heart attack. The scientist says the event changed his life forever. In an attempt to cope with grief, the future astrophysicist sought solace in science fiction literature and read the novel “The Time Machine” by H.G. Wells, after which time travel became a kind of obsession for him. According to Mallett, the first chapter of the work radically transformed his view on this problem. The scientist recalls: “The book changed my life. Namely – the first chapter. I still remember this quote: ‘Scientists know perfectly well that time is only a special kind of space.’ So why can’t we move through time?”
Ronald Mallett claims to have developed an equation for time travel after years of astrophysical research. The professor has spent his career researching black hole theory and Albert Einstein’s general theory of relativity. But the inspiration came to him while he was in hospital due to heart problems. “It turns out that black holes form a gravitational field that can create time loops that will allow us to travel back in time,” the scientist explains.
Ronald Mallett’s vision of a time machine is built on what he calls an “intense and constantly rotating beam of light” to manipulate gravity. It is proposed to use a ring of lasers to simulate the space-time warping effect of a black hole. However, such a device, as the professor puts it, would require “galactic-scale energy,” and he does not know what size the time machine would need to be to function. In addition, the scientist believes that time travel is possible, although it is unclear when it will happen, and his theory is clearly grounded. While critics believe that such a device would have to be very large, Professor Mallett hopes that one day he will make his idea a reality.
Some scientists are also exploring other options that could theoretically allow time travel. One concept is based on wormholes, or hypothetical tunnels that could exist in space and create shortcuts for travelling through the universe. If someone could create a wormhole and find a way to move one end of it at close to the speed of light, the end being moved would age more slowly than the stationary end. Whoever enters the travelling end of the wormhole and exits the stationary end will be in the past. Nevertheless, these ideas are still at a theoretical stage: we know about the existence of mole holes theoretically and mathematically, although scientists have not yet been able to detect them. However, if time travel is possible, and if Professor Mallett’s method is not to be used, then mole holes and black holes seem inevitable for such travel.
There are also paradoxes of time travel. For example, the famous “grandfather paradox” is a hypothetical problem that would arise if you travelled back in time and accidentally prevented your grandparents from meeting. This creates the paradox of your birth becoming impossible and raises the following questions: how were you able to time travel at all; if you travelled back in time, did you change the course of history; if your grandfather never met your grandmother, how were you born? Another paradox is that you go back in time and give this or that invention to some scientist. The question then arises whether that scientist actually created that invention. If not, and the invention was given to him through time travel, who was the inventor?
The famous physicist Stephen Hawking tested the possibility of time travel by organizing a dinner party, invitations to which he sent out with the date, time, and coordinates only after it had taken place. The scientist hoped that someone from the future with the ability to travel through time would read the invitation and attend the reception. However, no one came. As Hawking put it, “the best proof that time travel is not and never will be possible is that we have not been invaded by hordes of tourists from the future.”
Apparently, time travel will continue to be an abstract concept in practice, but we now know that it is theoretically possible, and Professor Mallett even started his experiments long ago. Who knows, if not us, then maybe our grandchildren will be able to try out the concept of such travel and experience the “grandfather paradox” on our older relatives. But then how were they born? How was history written? These are questions worth thinking about together. And even if there are no answers, it is good food for thought.