Let us recall the most basic concepts of speed, which teach in school, namely that speed – is a vector quantity. Those who remember that this vector is well known that the vector has a direction, moreover, the vector may not always be unidirectional. If time is inextricably linked with the speed that time – it's too vector quantity. And this is, in turn, suggests that it is tied to the direction of the velocity vector, that time can not be unidirectional, and this is quite easy to verify in practice. Take, for example, any movie. Until then, until we begin to view it, it does not speed, and hence the time it stopped. One may recall that a similar, we have already encountered when in the article "Speed" crossed the border the speed of light: no moving object in the form of material particles, so the movement of time is also absent. Including film, we turn and his time, and we can even adjust the speed of time.
And if we can turn in a movie clock? Without problems, but under one condition: we should have a movie player, remote control, so – and time. Without it, the movie with a given rate will move in one direction only. Does this example of an analogy with human life? Yes, the most direct. We move through life movie called "Destiny" in one direction and the one given velocity. Can a person change the speed and direction? Of course, can – this is the so-called time machine.