Time is nothing but a mind illusion!
Time travel has been, one of the most popular science fiction movies since decals. Many scientist believe that this could be possible with the right technology!
But is time travel actual possible?
No, time travel is not possible. I look at 'time travel' in a practical way. I have always considered 'travel' as a two way - to and fro - affair. (Is there any airline, ship, bus or any other commercial transport which operate a "one way" route - except a hearse?) However, most people accept that 'time travel' to the future is possible - at least theoretically - making use of TIME DILATION. When you travel at relativistic speeds, time slows down so when you return, you will see the rest of the world have gone ahead in time.
But what you fail to notice is that you are 'in the present' all the time. You just 'skipped' some time (days or years) by travelling at relativistic speeds, that's all. You meet the people whom you left behind - and depending on the time you have skipped, they may or may not recognize you, and for all practical purposes, they may have given you up for dead. How can we call this 'time travel'? If it is confusing, I shall explain it another way.
Let's say, you departed in 2017 and sped around the galaxy at warp speeds, and returned after one year, to find that the calendar on Earth shows 2024 instead of 2018. Actually, you have not stepped into the 'future'. The world is experiencing the year 2024 having crossed 2018,19,20,21, etc in the normal course, and reached 2024 which is the 'present' for all concerned. For you, since you have the memory that you departed in 2017 and spent only one year in space, but landed back on Earth in 2024, it is the FUTURE! It is the 'future' ONLY FOR YOU! How can we call this "time travel"? And what's the point?
On the other hand, consider this scenario. By using some kind of a 'time machine' you travel to the future - say, 10 years ahead - of course, you are in your 'present' in 2027, but when you return to where you started from (2017), you can relate to the rest of the world what you saw ten years in the 'future' and your experiences - and who knows, some photos, advanced technology, whatever. Now, THIS is time travel. To the whole world, you have been in the FUTURE and returned to tell the tale. Now, can you imagine this kind of 'time travel'? Even hypothetically it is not possible!
Now we will move to the next problem. You know about the four-dimensional Minkowski 'spacetime' conceiving 'space' and 'time' in a single formulation. Everything in the universe is moving both in space and time. Light travels in space for one year, and the distance covered in that time is called the 'light year'. The Earth rotates on it's axis, orbits the Sun, and moves along with the Sun around the Milky Way, the Milky Way itself is moving and so on. So, if you are travelling only in time, you will remain where you are in space. (I have travelled for one year in time from July 2016 to 2017, but I am still at home) So you need to travel in space, too. You need to find out where the Earth will be at a given time at a certain point in space in future. And you need to reach that point before the Earth arrives there - only then you can say that you are in the FUTURE. This is clearly a fallacy, because to the best of our knowledge at present, there is only one EARTH, so how can you find a 'FUTURE EARTH" by elsewhere?
In case you are wondering how fast we are moving in space right now, we are moving at a steady clip of 2.20 million kilometers per hour towards a specific region in space 150 million light years away known as the GREAT ATTRACTOR. Since I started keying this in half-an-hour ago, I have moved 1.10 million kilometers in space! You do the math if you want to go to the future ten years ahead and find out how far you need to travel.
Travel to the 'past' is just unthinkable! You may find out where precisely the Earth was at a certain time in the past and head for that point in space. But you need to travel backwards in time - which is just not possible. The Arrow of Time is the one-way direction of increasing entropy required by the second law of thermodynamics. This is now known as the "thermodynamic arrow."
Therefore, let us accept the fact, that wherever you knock around, at whatever unimaginable speeds you are doing it in the present, once you return to Earth, you are still in the present. You can never be in the 'future' or in the 'past' as both are only concepts in our minds - an illusion.