Convert classical electron radius to meter
Classical Electron Radius
The classical electron radius (re), also called the Lorentz radius, is a physical constant equal to approximately 2.818 × 10−15 meters. It is defined as the scale at which the electrostatic potential energy of a sphere of charge equal to the electron's charge equals the electron's rest mass energy. Though the electron is now understood to be a point particle, this quantity remains useful in quantum electrodynamics and atomic physics.
Meter
The metre (Commonwealth spelling and BIPM spelling) or meter (American spelling) (from the French unit mètre, from the Greek noun μετρούν, "measure") is the base unit of length in the International System of Units (SI). The SI unit symbol is m. The metre is defined as the length of the path travelled by light in a vacuum in 1/299,792,458 of a second.
The metre was originally defined in 1793 as one ten-millionth of the distance from the equator to the North Pole along a great circle, so the Earth's circumference is approximately 40000 km. In 1799, the metre was redefined in terms of a prototype metre bar (the actual bar used was changed in 1889). In 1960, the metre was redefined in terms of a certain number of wavelengths of a certain emission line of krypton-86. In 1983, the current definition was adopted.