The internet is a small place. Free physics books are found on the web as
frequently as birds are found in aquaria. Here are the best ones:
• Friedrich Herrmann's excellent, short and freely downloadable physics textbook for secondary school, The Karlsruhe Physics Course, can be downloaded at www.physikdidaktik.uni-karlsruhe.de/index_en.html. It is available in several languages. This book is also recommended if you – girl or boy – need to repeat what you learned or should have learned about physics, the science of motion, before the age of 18. If you are a professional physicist and are interested in the background, you might also read the 2013 paper by C. Strunk and K. Rincke.
• Pearls for every physicist are the fallacies about physical concepts collected by Friedrich Herrmann, Historical Burdens on Physics, available at www.physikdidaktik.uni-karlsruhe.de/publication/pub_fremdsprachen/englisch.html.
• Two excellent introductory physics texts by Benjamin Crowell, Simple Nature and Light and Matter, as well as a textbook on calculus and a textbook on general relativity can be downloaded at www.lightandmatter.com.
• The Feynman Lectures on Physics, now over 50 years old, are online at www.feynmanlectures.info.
• For learning physics for university examinations, the site of reference is Rod Nave's Hyperphysics at hyperphysics.phy-astr.gsu.edu/hbase/hframe.html.
• The high-quality electrodynamics text by Bo Thidé, Electromagnetic Field Theory, can be found at www.physics.irfu.se/CED/Book/.
• The introduction to quantum mechanics that uses Schwinger's approach,
Quantum Principles and Particles by Walter Wilcox, can be downloaded
For an extensive list of internet links to physics information see Appendix C: Sources of information on motion in volume I of the Motion Mountain physics text.
News and comments from particle physicists that are worth reading:
- Jester's rare but excellent posts are found at resonaances.blogspot.de
- Tommaso Dorigo's informative posts are found at www.science20.com/quantum_diaries_survivor
Two well-known researchers have given up on unification but still write much about it:
- Peter Woit writes against string theory at www.math.columbia.edu/~woit/wordpress
- Lubos Motl writes in favour of string theory at motls.blogspot.com
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