Ocean-Navigation, Celestial Navigation, Astronavigation

Miscellaneous Things, mostly Physics by Examples


 

Note: This is a preliminary version, updates are planned, presumably also with further versions in English.

In the following a few physics problems of somewhat general interest are shortly discussed. The presentation is rather pragmatic, leaving out many (sometimes even necessary) details. Further explanations (corrections) may be provided at a later time. Downloads (mostly provided as pdf-files) open directly. - There is no guarantee whatsoever for correctness and there is no liability!
 

Scientific Discovery = arguments, why scientific discoveries cannot be planned in advance. 

Mathematik Einführung in Theoretische Physik = pragmatische Einführung in mathematische Methoden der Theoretischen Physik. 

Solving Linear Problems by Eigenvalues = Linear problems, formulated as eigenvalue-problems, are solved by "Diagonalisation". This is demonstrated on simple 2x2-matrices. 

From Quantum- to Classical-Physics = "Schrödingers Cat" or the transition from the microscopic quantum-scale to macroscopic classical scales is explained by collapse of the density matrix and decoherence (some knowledge of quantum-mechanical representation here is needed). 

Relativitätstheorie und GPS = Die praktische Wirkung der Einsteinschen allgemeinen Relativitätstheorie wird kurz erläutert am Beispiel der GPS-Satelliten-Positionsbestimmung. 

Bell'sche Ungleichung (kurz) = Die innere Unbestimmtheit der Quantenmechanik und das Fehlen verborgener Variablen wird durch die Verletzung der Bell'schen Ungleichung durch die Quantenmechanik bestätigt. 

Bell'sche Ungleichung (example) = Die innere Unbestimmtheit der Quantenmechanik und das Fehlen verborgener Variablen wird durch die Verletzung der Bell'schen Ungleichung durch die Quantenmechanik bestätigt. Das unheimliche Resultat legt nahe, dass sog. verschränkte Objekte auch über große Entfernungen instantan in Kontakt bleiben (Darstellung ähnlich J.J. Sakurai "Modern Quantum Mechanics" und F. Schwabl "Quantum Mechanics"). 

Adiabatische Thermodynamik = Vereinfachte Herleitung der adiabatischen Zustandsänderung mit einfachem kinetischen Modell. Anwendung: Adiabatischer Temperaturabfall in der Atmosphäre mit zunehmender Höhe.

Hydrodynamics = The theory of waves is presented in compact form. Various examples are shortly discussed: Waves against currents, the Kelvin-angle in the wake astern of a ship, the Prandtl-boundary layer, shallow-water waves, Tsunamis, Solitons and Freak waves as well as turbulence and the logarithmic velocity profile of the wind-field above ground are presented in (mostly) simple formulas. 

Yacht-turbulence = Yacht: hull-speed, turbulence, eddie-viscosity and energy-consumption. An outline is given about the friction of a yacht operating in displacement mode when eddies are resonsible for the main drag-resistance. Also the energy-consumption depending in third power upon the ships velocity is shortly explained.

Renormalization-Group-Method = A solid or liquid material may undergo a dramatic change in its properties depending on critical values of external parameters like temperature or pressure. A magnet for example loses its permanent magnetization at the so-called Curie-point. The materials behavior near such a critical point can be quantitatively described by a mathematical technique, called the Renormalization-Group method. It is illustrated by the example of Percolation in two dimensions..

FORTRAN77-Programmierkurs.zip = The fastest way to learn a programming-language goes by examples. Here is an example of two FORTRAN77-programs which perform basic things (a bit more than just print "Hello World"). You need a Fortran-Compiler to execute it on your PC, for example:   "FORCE209G77" with the free GNU-Compiler from http://force.lepsch.com/p/downloads.html. - Very usefull for numerical applications is book and source-codes of "Numerical Recipes" by Cambridge University Press.- An English version of the programs may become available in the future.

An explanation for the
Polar Light [Link] shown above and below (green colour due to atomic oxygen) can be found in the article on atomic spectra by Dietrich Zawischa, Leibniz Univ. Hannover.




COPYRIGHT: The material on this WEB-site is subject to the GNU General Public License (GPL), version 3 or any later version. - last update: 7. may, 2023 - H.Müller-Krumbhaar

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