Me too I was WP BOLD and changed it since it doesn t hurt and we can save the fine distinction that c is not only the speed of light in vacuum anymore though is equal to it for later Also I thought it was necessary to use SOME of the excerpted ref in the lede to remove the immediate question which otherwise arrises of why the speed of light is EXACTLY some value in m sec Answer because we fiddle with the metre to require that it be so having picked and fixed our arbitrary standard of time which is easier to do since there are so many good frequency standards out there for various processes