Notice that while you are reading this sentence you are time traveling, actually about 2 seconds in the future.
Since Stein developed the Theory of Relativity, we know that time is not the Universe background in which the events occur. Instead of it, it’s a dimension that presents the traditional deepness, high, and width that we are all used to.
In the same way we are able to walk on one side and on the other of a spatial dimension, we are also able to walk on time. It happens that different from what is seen in other dimensions, while traveling through the time there is no possible way to choose which direction to follow.
Believing or not, time passes by slower to Rubinho Barichello on the road than to us watching on the bleachers. But the difference is extremely small, in practice there is no difference.
Travel to the future is, actually, very simple. You just have to acelerate on the space and BUM! You’re in the future! The theory of relativity shows us that if we run very fast, weird things happen to us, we would be heavier and the time would pass slower (we even can't realize because it’s too subtle the period of time). When traveling in rhythms that begins to be compared to the speed of light, this difference starts to be more notable yielding the classic example of the trip to the future, known as the Twin Paradox.
Imagine two identical twins. One of they is recruited to be an astronaut and go to a experimental flight in a spatial craft able to achieve 50% of the speed of light! He leaves, goes to Alpha Centauri (the nearest star outside our solar system, a few light years away) and come back, a journey of 16 years. When he returns, surprise: his twin brother is now an elderly, dying, as he aged only the time of the trip.
What happens is that while the time passes by slower to the astronaut brother, the brother in the Earth was getting older. Then it’s possible to see the impressive variance between the twins age, that can be considered as a trip to the future made by the astronaut.
There are many physical arguments that suggests the infeasibility of returning to the past. We can cite, just to be started, that a trip like this would violate laws of conservation of matter and energy and that would probably require the implementation of a crossing that would be faster than the light to happen.
Although, the scientists already finded out , using Theory of Relativity, ways to dodge these difficulties and imagine time machines that, at least in principle, would work.
The wormhole is the blackhole exotic brother, if you want to travel in the past it’s the only way possible. Here is the theory: with the wormhole you can go far away as if it was close, but if the wormhole changes the space the time changes too. There are a lot of things that the scientists need to know and understand before beginning the experiences.
If you don’t believe in time travel you need to know the example of a man, he says and belivies to be from the future. The FBI arrested him for earning a bunch of money in the stock exchange, when they asked him his answer was: “I’ve traveled in the time".
