Introduction: Quantum Mechanics, Schrödinger, Hydrogen atom. Spectra |
This plate is from a discussion - based on some earlier lectures. It turns our attention to general problems, in contrast to those which can be solved analyticaly. When general problems are solved - numerically - the differences between the two fields appear in the sketched perspective. Classical physics - system of ordinary ( and in fact 1. order ) differential equqtions Quantum physics - allways over the whole space. And as mentioned in the next plate - complex numbers are essential Also sketched is a qualitative way to Schrödinger equation: from de Broglie's assumptions to Schrödinger's construction. No energy concept in Newton's time - see e.g. https://en.wikipedia.org/wiki/Conservation_of_energy https://en.wikipedia.org/wiki/Vis_viva It is energy in Quantum Mechanics ( or the Hamiltonian ) |
0005_Classical-Quantum.png
0005_Classical-Quantum.png |
Born's idea about probability density <-- from wavefunction is the cornerstone of quantum physics. Time dependent Schrödinger equation vs. Stationary problems ( time and space variable separation ) |
0010_Probability_Schrodinger.png
0010_Probability_Schrodinger.png |
Historically - allowed energies - explained the spectra. Here is a little exercise showing the relation between ENERGY LEVEL DIAGRAM and ENERGY SPECTRUM Historically it was wavelength spectrum - but Planck's work had shown the relation between energy and frequency (ant thus wavelength ) What we have demonstrated below: if you know the spectrum - you still do not know the energy levels in the lowest part of this plate is demonstrated that the same spectrum is consistent with both of the LEVEL DIAGRAMS |
0020_Levels_and_spectrum.png
0020_Levels_and_spectrum.png |
Above:
the lowest part
of the above plate demonstrated that the same spectrum is
consistent with both of the LEVEL DIAGRAMS ------------- So why are there only certain allowed energies? In one dimensional cases - for wrong energies the solution will "blow up" at infinity (also in 2-dim and 3-dim, but more complicated) Only for some energies the solutions vanish outside of the attractive region ( Hurrah when we hit .... ) |
0030_Eigenenergies.png
0030_Eigenenergies.png |
Above: lower
part - Coulomb problem = Hydrogen atom -
like Note the two forms - two "systems of
units" ( more about Gauss and SI later .... ) The good and bad solutions - in Schrödinger Toy Program (browser application) http://folk.uib.no/nfylk/PHYSTOYS/schroed/ |
0035_Schrodingers_Toy.png
0035_Schrodingers_Toy.png Getting to the good energy and good solution: - in Schrödinger Toy Program (browser application) http://folk.uib.no/nfylk/PHYSTOYS/schroed/ Playing_with_Schrodinger_Toy.png |
Above:
Playing with Schrödinger's Toy - snapshots. Question: HOW IS
THE ENERGY CHANGING from left to right DECREASING or INCREASING ????? Below: Kinetic energy operator - from momentum operator - gradient - Laplace operator - SPHERICAL COORDINATES |
0040_Radial_Coordinates.png
0040_Radial_Coordinates.png |
LAPLACE OPERATOR - Spherical coordinates Separation of Variables https://en.wikipedia.org/wiki/Laplace_operator#Three_dimensions |
0050_laplace_operator.png
0050_laplace_operator.png |
Additional snapshot: What also can be done with Schrödinger's Toy - Simple resonances |
Playing_MORE_Schrodinger_Toy |
Next time: Continue the work with LAPLACE OPERATOR - Spherical coordinates Separation of Variables More on hydrogen and experiments (and some historical facts) Visualization of the "orbitals" |
visit the last years' pages (open in new windows or tabs) http://folk.uib.no/nfylk/PHYS261/2015_08_20/ (See the levels database there, cf below) http://folk.uib.no/nfylk/PHYS261/2015_08_26/ http://folk.uib.no/nfylk/PHYS261/2014_08_19/ http://folk.uib.no/nfylk/PHYS261/2014_08_21/ http://folk.uib.no/nfylk/PHYS261/2014_08_26/ ( especialy the "Atomic Units part) We also mentioned this (see the details in the first link above) Level and lines diagrams from http://physics.nist.gov/PhysRefData/ASD/lines_form.html This diagram requires Java in the browser, at present de-popularized due to possible security problems when used on untrusted sites ( we can trust NIST - http://www.nist.gov) The atomic database: http://www.nist.gov/pml/data/asd.cfm |