3 ms·
Per http://www.bipm.org/en/CGPM/db/17/1/ http://www.bipm.org/en/CGPM/db/17/1/ "The metre is the length of the path travelled by light in vacuum during a time i
by nknighthb 13y ago
Per http://www.bipm.org/en/CGPM/db/17/1/ http://www.bipm.org/en/CGPM/db/17/1/
"The metre is the length of the path travelled by light in vacuum during a time interval of 1/299 792 458 of a second."