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I’m stuck at home, you’re stuck at home, we’re all stuck at home. Jetting off to some fun-filled destination like we used to might not be in the cards for a little while yet. What if you could zip through time at will, travelling forward to the future or backward to the past as easily as pushing buttons on the dashboard of a souped-up DeLorean, just like in the movie Back to the Future?

Time travel has been a fantasy for at least 125 years. What really kick-started scientific investigations into time travel was the notion, that time could be envisioned as a dimension, just like space. We can

move easily enough through space, so why not time? While the debate continues over whether travelling into the past is possible, physicists have determined that travelling to the future most certainly is.

Dueling theories

1) The physicist Albert Einstein's theory of special relativity proposes that time is an illusion that moves relative to an observer. An observer traveling near the speed of light will experience time, with all its aftereffects (boredom, aging, etc.) much more slowly than an observer at rest. That's why astronaut Scott Kelly aged ever so slightly less over the course of a year in orbit than his twin brother who stayed here on Earth. This kind of time travel may seem as negligible as the Kelly brothers' age gap, but given the hyper-accuracy of modern GPS technology, it actually does matter. If it can communicate with the satellites whizzing overhead, your phone can nail down your location in space and time with incredible accuracy.

2) Wormholes are theoretical "tunnels" through the fabric of space-time that could connect different moments or locations in reality to others. Also known as Einstein-Rosen bridges or white holes.

According to quantum mechanics, empty space is not empty. Instead, it is filled with pairs of particles that pop in and out of existence. If we can make a region where fewer pairs are allowed to pop in and out than everywhere else, then this region will have negative energy density.

However, finding a consistent theory that combines quantum mechanics with Einstein’s theory of gravity remains one of the biggest challenges in theoretical physics.

3) Theoretical physicist Amos Ori at the Technion-Israel Institute of Technology in Haifa, Israel, proposed a model for a time machine made out of curved space-time — a donut-shaped surround vacuum by a sphere of clear matter.

IDEAS IN JAMES GLEICK’S TIME TRAVEL: A HISTORY

Time travel turns out to be a very new idea that essentially starts with H.G. Wells’s 1895 novel, The Time Machine. Before that nobody thought of putting the words time and travel together. The beginning of the book is an attempt to answer the question, “Why? Why not before? Why suddenly at the end of the 19th century was it possible—necessary—for people to dream up this crazy fantasy?

  • In 1991, Stephen Hawking wrote a paper called “Chronology Protection Conjecture,” in which he asked: If time travel is possible, why are we not inundated with tourists from the future? He has a point, doesn’t he?

He even scheduled a party and sent out an invitation inviting time travelers to come to a party that had taken place in the past. Then he observed that none of them had shown up. [Laughs.] Hawking is one of these physicists who love playing with the idea of time travel. Hawking, like other physicists, decided, “Time is my business. What if we take this seriously? Can we express this in physical terms?” I don’t think he succeeded but what he proposed was that the reason these paradoxes can’t happen is because the universe takes care of itself. It can’t happen because it didn’t happen. That’s the simple way of saying what the chronology protection conjecture is.

  • In 2011, the Chinese government issued an extraordinary denunciation of the idea of time travel. What was their beef?

They thought it was corrupting and decadent. It’s a reminder that time travel is neither a simple nor innocent idea. It’s very powerful. It enables us to imagine alternative universes, and this is another line that science fiction writers have explored. What if someone was able to go back in time and kill Hitler?

  • More than 50 scientific papers a year are now published on the idea of time travel. Why are scientists drawn to the subject?

Scientists live in the same science-fictional universe as all the rest of us. Since we have machines that can take us into any of the three special dimensions, including balloons and elevators, why shouldn’t we have a machine able to travel through the fourth dimension?

  • If time travel is impossible, why do we continue to be so fascinated with the idea?

One of the other reasons is we want to go back and undo our mistakes. When you ask yourself, “If I had a time machine, what would I do?” sometimes the answer is, “I would go back to this particular day and do that thing over.” I think one of the great time travel movies is Groundhog Day, the Bill Murray movie where he wakes up every morning and has to live the same day over and over again. . Regret is the time traveler’s energy bar.

MY OPINION

Personally, I believe that time travel is achievable in theory and occurs on microscopic scales but even the universe has limits that we may never be able to exceed. With our current technology, time travel is more like a dream but with developments over time, we may invent objects able to withstand the pressure of superluminal travel. From Newtonian mechanics to nonlinear dynamics, the journey of physics is amazing, yet who knows what the future has in store for us?

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REFERENCES:

  • Einstein A (1916) Relativity: the special and general theory.
  • Wells HG (1895) The time machine. Signet classics
  • Is time travel possible? By Vicky Stein , Ailsa Harvey  
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