hat if I told you that we all are time-traveling, through every day, every hour, and every second in our lives? You would find that hard to believe. But scientifically, I’m right. And why so? Because in the most simplistic terms, time travel means traveling through certain points in space, via different moments in time. And we all do. The only difference is our rate of time travel. If you move from point A to point B in 1 hour, then I can say you’re time traveling at the rate of 1 hour per hour.
But that’s not what we’re interested in. The question here is: Can we move slower or faster than 1 hour per hour? And to understand this, you first need to have a little background info about Einstein’s concept of relativity. Einstein showed that time is an illusion; it is relative — it can vary for different observers depending on your speed through space. To Einstein, time is the "fourth dimension." Space is described as a three-dimensional arena, which provides a traveler with coordinates — such as length, width, and height —showing location. Time provides another coordinate; direction.
Einstein came up with 2 concepts: Special Relativity and General Relativity. Let me explain both the concepts through some easy, comprehensible examples:
A popular concept where one has to tell which twin will be older? The one that stays on Earth, or the one that travels in space, and then returns back to Earth?
Suppose you were to move at the speed of light (which is impossible but let’s assume it), then you’d be moving at the rate of 300,000 km per second. At this speed, time will move slower for you, than for objects at rest. So when you do return back to stationary things, they’ll have aged faster than you. This phenomenon is known as Special Relativity. In other words, you slow down time. For if you do travel that fast, then you can break 1 second into 1000 milliseconds, and experience each millisecond equivalent to a second. You’ve broken downtime into small fragments, and the faster you move, the smaller segments time can be broken down into.
The bending of the space-time fabric by bodies exhibiting gravitational fields.
The next concept is General Relativity. Picture a four-dimensional fabric called space-time. When anything that has mass sits on that piece of fabric, it causes a dimple or a bending of space-time. The bending of space-time causes objects to move on a curved path and that curvature of space is what we know as gravity.Since, general relativity causes bending in the space-time continuum, it makes time-travel to the past theoretically possible.
When we mess with physics, we’re bound to run into some problems. One of the most famous time paradox is known as the grandfather paradox. Suppose you were to time-travel back into the past, and kill your own grandfather. This would mean that you were never born in the first place. But then again, if you were never born, then how could you go back in time and kill your grandfather? Since it’s a never-ending loop, we can’t answer this decisively. However, the alternate theory suggested here is the multi-verse theory, or popularly known as the “alternate-timelines” theory. For every decision, you make when you time-travel into the past, a new timeline is created, where your action has unforeseen results. This theory suggests infinite timelines co-existing in the same time period. So killing your grandfather, will not alter the timeline where you’re from, but it will create another timeline, where you were never even born!!
The time-travel concept has been of peculiar interest to film-makers and authors since the late 1800s. HG Wells’ first introduced this idea in his book “The Time Machine” in 1895. Movies since the 1980s have used time-travel as the central plot of the story. Be it “Back to the Future”, “Interstellar”, or the more recently “Avengers: Endgame”, all these movies have utilized various forms of time-traveling to move the story forward. While “Back to the Future” displays time travel through instantaneous jumps in time, “Interstellar” relies more on the special relativity concept (traveling through a black hole), and “Avengers: Endgame” using the quantum realm to enter and exit through different points in time indicates the vast possibilities that time-travel has to offer.
The MCU employs the use of Quantum Realm to travel back in time and secure all the infinity stones to rebuild the Infinity Gauntlet.
So, in conclusion, is time travel really possible or not? And if you ask me, I’ll leave you with one simple question: If time travel was really possible, then why aren’t the tourists of the future still here?