1 The Physical Meaning of the Wave Function

2 Superposition creates regions of constructive and destructive diffraction according to the relative incidence of the waves. The light intensity is distributed by the square of the wave envelope: Wave Function for Light in Classic Mechanics  intensity = energy Volume unit

3 The beam of electrons is distributed according to its wavelike nature. Does each electron behave like a wave, hitting the screen in several places simultaneously? The Particle-like Nature of the Measuring Process

4 During the measurment the electron behaves like a particle: it can be in one place only. The wave function determines the distribution (probability density) for finding the electron in a specific position The Particle-like Nature of the Measuring Process

5 The information implicit in the wave function enables to transform between various presentations of the particle properties. Base Transitions FourierTransformFourierTransform g(k)  (x) The momentum picture: The position picture: The probability for finding a particle with a specific momentum

6 For a large number of n particles Wave Function for Light in Quantum Mechanics

7 Quantum Mechanics Postulates for a 1-dimension Free Particle 1.(The tools of the game) The system status can be described by a wavepacket (the board of the game) pertaining to the space of continuous functions on the x axis: 2.(The rules of the game) For each component in the wavepacket the following is true: 3.(The interface) the measuring action has the following probability of finding the particle in a single length element dx:

8 Probability Density The odds of finding a particle between x and x+dx: The odds of finding a particle between x 1 and x 2 : The odds of finding a particle in the whole space (normalization)