From d33e373b84fdd82507dd40c6a0a937a91ef88b05 Mon Sep 17 00:00:00 2001 From: Bryan Newbold Date: Fri, 23 Sep 2022 10:51:24 -0700 Subject: commit work from yesterday (thursday) --- log/2022-09-22.md | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) create mode 100644 log/2022-09-22.md (limited to 'log') diff --git a/log/2022-09-22.md b/log/2022-09-22.md new file mode 100644 index 0000000..c55dbe7 --- /dev/null +++ b/log/2022-09-22.md @@ -0,0 +1,20 @@ + +Two days ago, after running through Func Diff Geometry chapter, spent a while +reading Carroll Spacetime+Geometry, in early chapters. Particularly relevant +was the discussion of 1-forms ("dual vectors") and vectors and tensors. Tensor +language isn't really even used in this book, except in Appendix C. Should +probably work through that appendix in another week or two. + +--- + +Starting on chapter 4, about basis fields (basic vector fields and basis +one-form fields), both coordinate and non-coordinate. + +What is an example of a non-coordinate basis? Rotations! This will probably +come back up as... Lorentz transforms? Rotations of spacetime, as a change of +frame. + +Commutators! + +The commutator of two coordinate basis fields is zero. This is one way to tell +if basis fields are coordinate or non-coordinate. Is this sufficient proof? -- cgit v1.2.3