Metre(or meter) is the fundamental and Standard International unit of length. Since 1983, it has been defined as "the length of the path travelled by light in vacuum during a time interval of 1/299,792,458 of a second".
Metre(or meter) is the fundamental and Standard International unit of length. Since 1983, it has been defined as "the length of the path travelled by light in vacuum during a time interval of 1/299,792,458 of a second".