20th Century physics really began in 1865 with Maxwell'sEquations. It was not realized at the time that these incredible equations, which describe all of electromagnetism, exhibit two symmetry principles, Lorentz Covariance and Gauge Symmetry, which by 1930 had become the basis of all fundamental physical descriptions of the sub-microscopic phenomena of nature!
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For our purposes, Lorentz Covariance means simply that the mathematics used in expressing a theory is entirely consistent with Einstein's Theory of Special Relativity, first presented in 1905. And so it is with a presentation of the basic concepts of this theory that our course must naturally begin.
YOUR FIRST ASSIGNMENT IS TO READ TEXT CHAPTERS 1, 2 and 3, which summarize the pre-history of 20th Century physics... this material will not be covered in lectures or on homework. The class presentations will begin with Ch. 4, summarizing the basic ideas and concepts from Einstein's 1905 efforts.
When I was an undergraduate, I wondered when I would ever be offered a course that covered the latest developments in physics, instead of presenting more details of the physics of 100 or 300 years ago. Well, this is that course. Enjoy.
Physics before 1900
described a mechanical universe... the behavior of
systems visible to the naked eye, or at worst requiring
a microscope or telescope to study them. Maxwell
was the first to encounter physics that he could not
visualize with a mechanical model. |
Physics after 1900 needed to describe systems and processes whose properties and behavior were abstract and generally impossible to visualize. The mathematical descriptions took advantage of principles, patterns, symmetries and invariances of many kinds, that generally had no counterpart whatsoever in the "mechanical" behavior of systems encountered in everyday life. |