Quantum Mechanics

Explaining the behavior of nature at or below the atomic level
      Einstein, Planck, Heisenberg, Bohr , Compton, de Broglie, and many others contribute to the                          development of a quantum theory.

Beginning where we left off with Bohr's description of the atom

   Compton shows that light is a particle (compton scattering)
   
   Louis de Broglie (1892-1987)- postulates (1924) that
not only photons, but  perhaps all forms of                  matter have both particle and wave properties using the relation λ = h/mv

     Erwin Schrodinger (1887-1961)- Uses de Broglie's suggestion to develop a wave mechanics            
              formulation of quantum physics. In 1926 he publishes the Hamiltonian formulation of
               quantum theory.


     Hiesenberg - tells us that we can’t know both the exact position (x) and momentum (p) of a particle                     simultaneously.
                From this he forms the
Heisenberg uncertainty principal (1) Δx*Δpx ≥ h/ 4π. This equation has a few cousins, the Heisenberg uncertainty principal for energy and time (2)( ΔE*Δt =h/2π) which when considering ΔE=Δm * c2 can be rearranged to: (3) Δm*Δt = h/ 2π c2 [2 p672]. Which leads to the implication that for a Δt we cannot be sure of how much matter is in a location in space, so matter can appear and then disappear into nothingness. No particle can appear spontaneously by itself. For each particle created an equal mass and opposite charged antiparticle is created, so equal amounts of matter and antimatter are created and then disappear (pair production).

    Dirac -discovers a relativistic equation for the electron (1928) . He found that solutions of this        
              equation exist for negative energies as well an positive and had the idea to interpret these        
              solutions as antiparticles.

In 1932 Carl Anderson experimentally observes the antimatter brother of the electron, the positron

This is where matter  and antimatter symmetry is born.


   home           Next QFT