*speed of light in vacuum (national institute of standards and technology nist)*definition of the metre (international bureau of weights and measures bipm)*data gallery michelson speed of light (univariate location estimation) (download data gathered by aa michelson)*subluminal (java applet demonstrating group velocity information limits)*de mora luminis at mathpages*light discussion on adding velocities*speed of light (university of colorado department of physics)*c speed of light (sixty symbols university of nottingham department of physics )*usenet physics faq*the fizeau rapidly rotating toothed wheel method