Is Time Travel Possible?
Time travel has been the most exciting topic for me, and well Bermuda triangle. No matter how many theories we discuss or watch tons of Youtube videos to find out more information about Time travel, one question remains and that is, ‘Is Time travel possible?’.
What is Time travel?
Time travel — moving between different points in time — has been a popular topic for science fiction for decades. Franchises ranging from "Doctor Who" to "Star Trek" to "Back to the Future" have seen humans get in a vehicle of some sort and arrive in the past or future, ready to take on new adventures. The reality, however, is more muddled. Not all scientists believe that time travel is possible. Some even say that an attempt would be fatal to any human who chooses to undertake it.
Physics is the only science that explicitly studies time, but even physicists agree that time is one of the most difficult properties of our universe to understand. Even in the most modern and complex physical models, though, time is usually considered to be an ontologically “basic” or primary concept, and not made up of, or dependent on, anything else.
What is time? While most people think of time as a constant, physicist Albert Einstein showed that time is an illusion, it is relative that 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 traveller with coordinates, such as length, width and height, showing location. Time provides another coordinate, direction, although conventionally, it only moves forward. (Conversely, a new theory asserts that time is ‘real’).
Albert Einstein developed a theory called Special Relativity. The ideas of Special Relativity are very hard to imagine because they aren't about what we experience in everyday life, but scientists have confirmed them. This theory says that space and time are really aspects of the same thing—space-time. There's a speed limit of 300,000 kilometres per second (or 186,000 miles per second) for anything that travels through space-time, and light always travels the speed limit through empty space.
Special Relativity also says that a surprising thing happens when you move through space-time, especially when your speed relative to other objects is close to the speed of light. Time goes slower for you than for the people you left behind. You won't notice this effect until you return to those stationary people.
Let’s read up some Time travel theories, shall we?
1) Infinite cylinder
Astronomer Frank Tipler proposed a mechanism (sometimes known as a Tipler Cylinder) where one would take the matter that is 10 times the sun's mass, then roll it into very long but very dense cylinder. After spinning this up a few billion revolutions per minute, a spaceship nearby — following a very precise spiral around this cylinder — could get itself on a "closed, time-like curve", according to the Anderson Institute. There are limitations with this method, however, including the fact that the cylinder needs to be infinitely long for this to work.
2) Black holes
Another possibility would be to move a ship rapidly around a black hole or to artificially create that condition with a huge, rotating structure. "Around and around they'd go, experiencing just half the time of everyone far away from the black hole. The ship and its crew would be travelling through time," physicist Stephen Hawking wrote in the Daily Mail in 2010.
3) Time machines
It is generally understood that travelling forward or back in time would require a device — a time machine — to take you there. Time machine research often involves bending space-time so far that timelines turn back on themselves to form a loop, technically known as a ‘closed time-like curve’. To accomplish this, time machines often are thought to need an exotic form of matter with so-called ‘negative energy density’. Such exotic matter has bizarre properties, including moving in the opposite direction of normal matter when pushed. Such matter could theoretically exist, but if it did, it might be present only in quantities too small for the construction of a time machine.
4) Grandfather paradox
Besides the physics problems, time travel may also come with some unique situations. A classic example is the grandfather paradox, in which a time traveler goes back and kills his parents or his grandfather, the major plot line in the "Terminator" movies or otherwise interferes in their relationship, think "Back to the Future", so that he is never born or his life is forever altered. If that were to happen, some physicists say, you would be not be born in one parallel universe but still born in another. Others say that the photons that make up light prefer self-consistency in timelines, which would interfere with your evil, suicidal plan.
5) Cosmic strings
Another theory for potential time travellers involves something called cosmic strings — narrow tubes of energy stretched across the entire length of the ever-expanding universe. These thin regions, left over from the early cosmos, are predicted to contain huge amounts of mass and therefore could warp the space-time around them. Cosmic strings are either infinite or they’re in loops, with no ends, scientists say. The approach of two such strings parallel to each other would bend space-time so vigorously and in such a particular configuration that might make time travel possible, in theory.
Is it possible?
In the past few years, some scientists have used those distortions in space-time to think of possible ways time machines could work. Some like the idea of "wormholes," which may be shortcuts through space-time. This and other ideas are wonderfully interesting, but we don't know at this point whether they are possible for real objects. Still, the ideas are based on good, solid science. In all time travel theories allowed by real science, there is no way a traveller can go back in time to before the time machine was built.
I am confident time travel into the future is possible, but we would need to develop some very advanced technology to do it. We could travel 10,000 years into the future and age only 1 year during that journey. However, such a trip would consume an extraordinary amount of energy. Time travel to the past is more difficult. We do not understand the science as well.