When we start walking feet from the ground or from the floor; on a very smooth floor or on ice, from which the foot can not start, can not go. The locomotive when the movement starts "leading" wheels from the rails: rails if oil, the locomotive will remain in place. Sometimes (in the ice) in order to move the train from the place, the rails in front of the leading wheels of the locomotive is sprinkled with sand from a special device. When the wheels and rails (at the dawn of Railways) did the timing, it came from the fact that the wheels have to start from the rails. The boat pushes water from the blade side of the wheel or propeller. The plane takes off from the air by means of the screw - propeller. In short, in whatever environment or move the subject, he leans against it with his movement. But can any body begin to move, with no support outside of yourself?
It would seem, strive to implement such a movement is still trying myself to raise hair. As you know, this attempt is still only managed Baron Munchausen. Meanwhile, it is this seemingly impossible movement often occurs before our eyes. However, the body cannot bring themselves entirely in the movement among the internal forces, but it may cause some substances to move in one direction, the other in the opposite. How many times have you seen the flying rocket, and wondered whether the question: why is it flying? In the rocket we have a clear example of just that kind of movement, which now interests us.