Interesting blog. Did you enter it into our list math blogs ?
]]>I have only now discovered that Gonzalo Reyes is (or has been) running a blog where he has posted lots of useful-looking notes.
For instance in the Physics-section he has a long series of expositions on basics of differential geometry with an eye towards general relativity in terms of synthetic differential geometry. I have added pointers to this to various related entries now.
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