## Friday, October 7, 2011

### Wave-particle duality a Principle of Quantum Mechanics

Wave-Particle Duality: the tendency of for light and matter to exhibit the properties of both waves and particles. It is a key concept of quantum mechanics.

Subatomic particles exhibit this dual nature in that they some times act like particles, exhibiting properties like scattering and at other times they act like waves, exhibiting properties like interference and diffraction.

The photoelectric effect in which photons of light eject electrons from a sheet of metal just as interacting partials should behave.

The Davission-Germer experiment where an electron beam is aimed a nickel crystal and the resulting scattering has peeks and valise do to diffraction.

The wave length of a particle's wave is l = h / p.
l is the wave length
p is momentum
h = 6.626 X 10-34 J * S - Planck's constant
This relationship is just the first part of wave particle duality.

Wave actual function is denoted by Y (Psi).  While the exact formula varies with the situation, the wave function is always a complex number. It is related to the probability of finding the particle at a given point in pace.

The probability of finding a partial at a given point in space is denoted by |Y(x)|2.
Also denoted by Y* Y  .
Complex number:    Y = A + iB
Complex conjugate: Y* = A - iB
Over all space the probability density = 1.

In conclusion matter behaves as both particles and waves. The wave nature is related to the probability of finding a particle at a given location at a given time.