Convert meters to miles, m to mi

Researchers have sought and continue to link basic physical quantities with fundamental constants that can be measured at any time with good reproducibility. A typical example is the unit of length. 

 

At first, the meter was defined by the circumference of the globe, then by the wavelength of specific radiation: since 1927 – by the wavelength of the red line of cadmium Cd, and since 1960 – by the radiation of the krypton isotope 86Kr in the orange region of the visible spectrum: a meter is a length equal to 1,650,763.73 wavelengths in a radiation vacuum corresponding to the transition between the 2p10 and 5d5 levels of the krypton-86 atom. In 1983, the 17th General Conference on Weights and Measures was held. A new definition of the meter has been established based on the precise measurement of the speed of light. According to this definition, the meter is defined as the distance that light travels in a vacuum in 1/299,792,458 seconds. The speed of light in a vacuum is accurately measured as c = 299,792,458 meters per second. This fundamental constant of nature was chosen to define the unit because it allows for precise measurements. When scientists know time about light manages to travel this distance, scientists can accurately measure the standard length of a unit.