What travels at 299,792,458 metres per second?
Standard (metrology) direct relationship to fundamental physical constants. In contrast, the reference standard for the metre is no longer defined by a physical object (as the former international prototype metre (IPM) or originally the "mètre des Archives"). In 1983, the standard metre was redefined as the distance light travels in a vacuum during 1/299 792 458 of a second. Secondary reference standards are very close approximations of primary reference standards. For example, major national measuring laboratories such as the US's National Institute of Standards and Technology (NIST) will hold several "national standard" kilograms, which are periodically calibrated against the IPK and each
Mississippi Highway 792 Mississippi Highway 792 Mississippi Highway 792 (MS 792) is a road in eastern Mississippi. It starts at U.S. Route 45 (US 45), and travels east. Near halfway of the route, SR 792 turns south and continues to its eastern terminus at MS 388. The highway was designated in 1998, and no major changes have been made since. MS 792 is located in southern Lowndes and northern Noxubee counties. In 2012, Mississippi Department of Transportation (MDOT) calculated as many as 1,800 vehicles traveling west of Trinity Road and Weyerhaeuser Road, and as few as 540 vehicles traveling south of Bluitt Road.