Convert from bohr to mark twain

Unit Definition (bohr)
The Bohr is a unit of distance commonly used in particle physics. It was named after the Danish physicist Niels Bohr (1885-1962), who explained the structure of atoms in a famous paper in 1913. The Bohr radius represents the mean distance between the proton and the electron in an unexcited hydrogen atom. It equals about 52.918 picometers (pm), or 52.918 x 10e-12 meter.

Unit Definition (mark twain)
The mark twain or twain is an old word for the number two, derived from the Anglo-Saxon twegen. The American author Samuel Clemens (1835-1910), who had been a riverboat pilot on the Mississippi in his youth, took his literary name from a traditional riverboat phrase "mark twain", meaning "exactly two" fathoms of water. This was the minimum depth needed for the boats to operate safely without running aground.