Current Reading

This blog is primarily for me to blog my responses to books that I'm reading. Sometimes I blog about other stuff too, though.

I'm currently reading Edward Teller's Memoirs.

Word cloud

Word cloud

Tuesday, July 19, 2016

Principia, Book 1, Section 1

This section is entirely geometric proofs of lemmas concerning either areas or ratios of lengths or areas in limiting cases as angles or lengths approach zero, or as the number of divisions becomes infinite.  It's a hard slog, and I have to admit that I mostly read to get a sense of Newton's style rather than the details.  I am proud of myself, though, for being able to deduce that Lemma 10 is a proof that dx=0.5*a(0)*dt^2 for small dt and v(0)=0 and that Lemma 11 is a proof that y~theta^2 for a pendulum set up such that y=0 when theta=0.

Section 2 is physics rather than geometry; hopefully it will be an easier read.

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