Convert from mark twain to angstrom

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.

Unit Definition (angstrom)
The Angstrom is a metric unit of length, equal to 0.1 nanometer or 10e-10 meter. Angstroms are most often used to measure the wavelength of light and are commonly used by chemists and physicists in the field of spectroscopy. One of the pioneers of spectroscopy was the Swedish physicist Anders Jon Ångström (1814-1874), after whom the unit is named.