Time travel has been a fantasy for years, H.G. Wells was the first one to pen a ground-breaking novel, “The Time Machine”, in 1895, on which physicists and philosophers wrote serious papers. The novel focuses on the time traveler’s journey into the far future. Two films adopted the novel with the same name and has also inspired many works of fiction. This work of Wells hyped the concept of time travel by using an apparatus to travel forward or backward through time.
Before time travel let’s know what time is?
Linear time is nothing but, a combination of 60 seconds which make a minute, 60 minutes which make a hour and 24 hours which make a day. Considering this, if someone asks you to draw time, one will end up drawing a clock or calendar. But is this what time is? The answer is ‘no’. A Calendar or clock is just a physical representation of the ‘passing of time’, that runs our lives.
Aristotle once said, “Time is the most unknown of all unknown things.”
Time is not retrievable; it is like an arrow- it moves in one direction; forward. Scientists called this the Arrow of Time. It originated at the Big Bang, where our history lies, through the present, where we are prisoned towards the unknown and turbulent future
The arrow of time originated at the Big Bang and has been moving forward ever since. The second law of thermodynamics represents this, known as entropy, which measures disorder in the universe. At the Big Bang, all the matter in the universe was compacted into an infinitely small point. This is considered as a very low entropy situation, a very orderly situation but now it’s expanding regularly. Hence, this universe is this big as you see today.
Because of entropy and the arrow of time we have galaxies, stars, planets, and even life. Entropy is the reason you can differentiate between past and future. It explains why every living being is born and then lives and then dies – always in that order. If there were no entropy and change in the universe one would not be able to tell the difference between two years.
Investigations of the relationship between space and time led physicists to define the spacetime continuum. Space-time is a conceptual model which consists of three dimensions of space with one dimension of time, hence space-time is a 4-dimensional object. The primary framework for understanding how spacetime works is General relativity. This general relativity describes gravity as bending or warping of space-time. Special relativity or special theory of relativity is another scientific theory regarding the relationship between space and time. This doesn’t give us a way of going back in time instead, it gives us a way of going into the future.
Clifford Johnson, a physicist at the University of Southern California, says that the theory of Special relativity “establishes that time is much more similar to space than we had previously thought,” “So maybe everything we can do with space, we can do with time.”
According to the current physical theories, space-time explains the unusual relativistic effects that arise from traveling near the speed of light as well as the motion of massive objects in the universe. Albert Einstein, a physicist, developed the idea of space-time as part of his relativity theory. NASA says before Einstein’s pioneering work, scientists explained physical phenomena in two different theories: Isaac Newton’s laws of physics described the motion of massive objects and James Clerk Maxwell’s electromagnetic models explained the properties of light.
Time travel is the concept of traveling from one point of time to another (either to past or future), through the hypothetical device, that is., Time Machine. No one knows whether time travel is physically possible or not. Travel to the future is an extensively observed phenomenon and well comprehended within the framework of special relativity and general relativity. To travel past, search for solutions in general relativity required that allow traveling, such as a rotating black hole. Theoretical physics only supports traveling to an arbitrary point in spacetime and is usually linked with quantum mechanics or wormholes. Physicists have also conjectured the implications of an exotic structure known as a wormhole. Wormholes can connect one time in space-time with another.
An astronaut who enters a wormhole in the Andromeda Galaxy in the year 3000 might find itself emerging from the other end in our galaxy, in the year 2000. But there’s a catch: While black holes exist in nature—wormholes are far more speculative.
What would you do if time-traveling became possible? There’s a high chance for the answer that they will try to change the past or see the future before it’s due. Many people around the world are fascinated by the idea however no person has ever demonstrated the kind of back-and-forth time travel seen in sci-fi novels or films. In the book “Black Holes and Baby Universes”, a physicist Stephen Hawking pointed out that “The best evidence we have that time travel is not possible, and never will be; Hordes of tourists have not invaded from the future.
The unimaginable; Time travel:
Time Machine: The term “time machine”, coined by H. G. Wells in his book The Time Machine in 1895, is used universally to date. Although to date, we do not have any apparatus to travel through time. Einstein’s theory of relativity links time and space together. He even said that the universe has a speed limit, i.e., nothing can travel faster than the speed of light (186,000 miles per second), which means, the faster you travel, the slower you experience time.
Experiment: To prove the theory mentioned above, Scientists experimented with two clocks, set to the same time. There was one clock on the airplane, while the other was on Earth. That airplane flew in the same direction as Earth rotates. After the airplane completed its one round around the world, scientists compared the two clocks. The clock on the fast-moving airplane was slightly slower in time than 1 second per second when compared with the clock kept on earth.
References in fiction:
Media: There is no time machine that can take us hundreds of years into the past or future. Such time travel is only possible in our imaginary land, that is, in books and movies.
Short story: “The Clock that Went Backward” is a fantasy short story by Edward Page Mitchell, about a clock that takes people back in time. A 16th-century antique clock reverses the flow of time. This allows the two boys to relive and participate in a historical adventure. This is the first story to use a machine for time travel.
Novel: “The Shining Girls” written by Lauren Beukes is the story of a serial killer named Harper Curtis who falls upon an abandoned house that allows him to travel in time. He took advantage of it and visited his victims at different times of their lives before killing them. Kirby, another character, survives Harper’s attack and, along with a former homicide reporter, tries to unravel the mystery. This book has a lot of violence, so not everyone might like it. But it’s an interesting take on the time travel story.
Film: “Interstellar” directed and produced by Christopher Nolan in 2014. The film depicts some of the implications of Einsteins’ general relativity theory. The set of the film is a dystopian future where humans struggle to survive. In the film, astronauts travel through a wormhole near Saturn in search of a new home for mankind; where years pass like a minute. An epic Science-Fiction and one of the best descriptive movies of the 21st Century is Interstellar. There are innumerable numbers of books, films, and series made on time travel in which characters also carry devices to travel to different times.