Modern Physics
Fall/Winter 1900, Max Planck’s paper “Ueber das Gesetz der Energieverteilung im Normalspectrum”, Annalen der Physik IV, 553 (1901) – peak in 1920s/30s
Two major parts: modern relativity, first 4 - 6 lectures
Quantum mechanics and its applications, rest of the course –also main content of Phys 312 to follow next quarter ----------------------------------------------------------
What is Physics all about? concepts and their connection, i.e. mathematically formulated equations/laws, concepts and laws are derived from interplay between theory and experiment, this makes sure only good theories survive and theories get better over time some “fundamental” concepts such as space and time are much older than Physics and are sort of common sense knowledge (Kant’s “a priori” concepts) and may even be inherited genetically
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but: Werner Heisenberg (in Physics and Philosophy)
“Any concepts or words which we have formed in the past through the interplay between the world and ourselves are not really sharply defined with respect to their meaning; that is to say, we do not know exactly how far they will help us in finding our way in the world. ... This is true even of the simplest and most general concepts like “existence” and “space and time”...
The concepts may, however, be sharply defined with regard to their connections. This is actually the fact when the concepts become a part of a system of axioms and definition which can be expressed consistently by a mathematical scheme. Such a group of connected concepts may be applicable to a wide field of experience and will help us to find our way in this field. ...
So modern physics will be in large parts contrary to our intuition because it deals with the very fast, i.e. speeds comparable to the speed of light and the very small, atoms, molecules, elemental particles.
Our (possibly inherited) lack of appreciation that the world of the very fast and the world of the very small may well be very