Well, there are more than a few scientists that believe that time travel is possible. But there are also more than a few that disagree. Time is a phenomenon experienced due to the difference in speed of energy moving at the speed of light and that of stationary objects. The energy is moving at such a speed that it doesn't experience time at all and Basically, time is the stationary object playing catch up. Now one of the problems with time is that it is relative. Very very relative. And it is relatable to gravity.
The bigger an object is, the more gravity that will be experienced on its surface and the less time it experiences. This means that bigger planets with higher levels of gravity experience less time. So a day on that planet can be years here. Because of the difference in gravity. So if you should find yourself on a planet ten times larger than earth and the gravity is 100 times greater, spending a day there will be like a hundred years here. When you come back, years would have passed. Thus the illusion of time travel
Also objects moving fast experience less time than slow moving objects. Let me take an example. If you put a track around the planet and put a bench at the starting line, then a car takes off at a fraction of the speed of light, to the man on the bench, he is gone for a long time but to the driver, it only takes him a moment to go around the planet. This is because at that speed, he experiences less time and so appears to be time travelling.
These are the only two ways that have been shown to have the most possible results of time travel and even these are mostly impossible.
Most people have a wrong idea about what time really is. The reason that time goes forward in our universe (The arrow of time) has to do with the second law of thermodynamics. As one goes "forward" in time, the second law of thermodynamics says, the entropy of an isolated system can increase, but not decrease. Hence, from one perspective, entropy measurement is a way of distinguishing the past from the future.
According to Albert Einstein's theory of relativity, the 3 dimensions of space fuse together with one dimension of time into the 4th dimension (space time). There is no such thing as past, future or present, that's a human concept. In the 4th dimension the past, future and present all exist simultaneously. That's what Albert Einstein meant when he said: "Reality is merely an illusion, albeit a very persistent one."In theory time travel is possible on 2 ways:
Fly faster than the speed of light.
Fly through a transversable wormhole ( known as Einstein-Rosen bridges. )
If an object tries to travel 186,000 miles per second (=speed of light), its mass becomes infinite, and so does the energy required to move it. For this reason, no normal object can travel as fast or faster than the speed of light. Wormholes can be a better solution to time travel but our technology doesn't allow it. In theory time travel is possible but it's something very hard to do (almost impossible) because of the enormous amounts of energy that are required.
In fact, time travel has been done before but not in a spectacular way. The first time traveller ever was the Russian astronaut Sergei Krikalev. He has spent in total 803 days, 9 hours and 39 minutes in time in an orbit around the Earth. Because of the effects of time dilation, Krikalev has actually lived for 0.02 seconds less than everyone else on Earth - effectively, he's travelled 0.02 seconds into his own future.
According to the theory of relativity, time dilation is a difference in the elapsed time measured by two observers, either due to a velocity difference relative to each other, or by being differently situated relative to a gravitational field. As a result of the nature of spacetime, a clock that is moving relative to an observer will be measured to tick slower than a clock that is at rest in the observer's own frame of reference. A clock that is under the influence of a stronger gravitational field than an observer's will also be measured to tick slower than the observer's own clock.
There are some philosophical problems with time travelling. The first problem is: when you travel back in time you could alter the future. But the present, future and past already exist simultaneously so you can't alter it. That would also mean that there is no such thing as free will. Besides that, nobody has ever met time travellers. If people of our future could go back, why don't we meet them?
The multiverse and string theory provides the answers to these problems. When you travel back in time by a wormhole, you probably enter a parallel universe.
The multiverse is a hypothetical group of multiple universes including the universe in which we live. Together, these universes comprise everything that exists: the entirety of space, time, matter, energy, the physical laws and the constants that describe them. The different universes within the multiverse are called "parallel universes", "other universes", or "alternative universes".
I think in theory it is actually possible. It is to break the light speed in order to travel into time. I don't know if it's actually possible as no one has proven that it works yet. However, maybe one day, in the future, after a hundred or two hundred years from now, it can be cracked the code of time travel.
In some documentaries, I've seen on youtube that there are controversial time travelers claiming that he is from the future. One question that was asked by the interviewer on video , " Do you think that Donald Trump is going to win the next election? " , According to the time traveler, Donald Trump is going to be re-elected as the President of the United States again in the future. Then there is this question that lies,
Would there be a butterfly effect? If for example, we actually travelled back to the past and destroyed certain plants or even kill a butter fly and it affects the future. I wonder if it would be possible. I think it would be really scary to be the first person to travel in time, what if we travelled in time and got stuck somewhere in the time warp then what happens? Would we actually be stuck into this place of no return and this place would be free of darkness.
Well, in theory time travels are possible, but only till one day, we make it possible will we be able to see this. If really there was the butterfly effect, then imagine those bad guys who went back to the past and warned Hitler about his defeat. What if we went to the past but never would be able to come back to the present time?
We are doing it. One second at a time.
Time travel is only possible in the imagination and in movies. Some people believe that inventions could be made that would enable them to travel either to theI'd past or to their future. That can never be possible. I've watched several movies that made it seem that such is achievable, but those are just people's imaginations.
What would one achieve from traveling into the past or future if you couldn't alter it. Time travel is just a figment of people's imaginations. There's no technology anywhere that can take you into the future or your past. You can be made to remember your past because such past are already imprinted in your memory but not the future that you've never been in and can't tell how it looks like. So time travel is just man's imagination
Who knows if we will ever find out. The Back to the Future films have now finished and Michael j Fox is getting too old now. The De lorean car that was the time machine is now scrap somewhere and the De Lorean factory closed down many years ago.
All the secrets were lost and we have to start again.