Hello,
Michael Godfrey forwarded the following to me from this list, written by John S.:
This [online edition of The Feynman Lectures] does not render well in my browser. The MathJax numbers use a different font with a different weight compared to the surrounding text, which looks very bad.
...
MathJax looks bad in Google Chrome on OSX unless I right click and go choose Math Settings-Math Renderer and select SVG as the renderer. The HTML-CSS, Common HTML (which was the default), and Fast HTML all look really bad for me.
This concerns me because I am the editor of The Feynman Lectures on Physics (FLP) and the publisher of the online edition. I also find it surprising because I use Google Chrome on OSX and don't see any problems with the rendering of mathematics by MathJax in the online edition of FLP.
That VG rendering works right but HTML-CSS doesn't on your system suggests a font problem... but (if you haven't changed the MathJax defaults) any fonts missing from your OS should be downloaded automatically when they are needed.
I would like to help resolve this problem, if I can.
Mike Gottlieb