Microworld control principles

Control of microworld processes has a strong allure, which has stimulated fervent activity. Armed now with knowledge of the fundamental control principles and the necessary control tools, microworld events are beginning to succumb to active manipulation. 

Initially, students are encouraged to think in terms of orthogonal velocity components. They are given tasks, such as the one illustrated in figure 19.4, where one student has to control the motion of the horizontal arrow and another student has to control the motion of die vertical arrow. By performing this task, students should induce two principles. The first is that the law induced in the first microworld, concerning the additivity of impulses, applies to this new vertical dimension of motion. The second is that impulses plied in the vertical dimension have no effect on the dot s horizontal velocity, and vice versa -- hi other words, the dot s horizontal and vertical velocity components are independent of one another. 

The above picture of wave interference manipulation is now accepted as the basic operating principle for high finesse control of microworld events described by the laws of quantum mechanics. We may naturally then ask whether all control will be rapidly lost if incoherent events, such as collisions or other uncontrolled environmental disturbances, are present. 

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