Convert from shackle to hubble

Unit Definition (shackle)
The shackle is a traditional unit of length used for measuring the lengths of nautical cables and chains, especially anchor chains. Anchor chains are formed by using shackles to join short lengths of chain. When the anchor is dropped and the chain runs out, a seaman counting the number of shackles can report the total length of chain deployed. The size of the unit therefore varied somewhat, depending on the length of the short chains used. In Britain, the unit became standardized in the 16th century at 12.5 fathoms (75 feet or 22.86 meters). In 1949, the Royal Navy adopted a length of 15 fathoms, which is 90 feet or 27.432 meters; this brought the British shackle in line with the U.S. unit, which is usually called the shot.

Unit Definition (hubble)
The hubble is a unit of distance sometimes used in astronomy. The hubble is a gigantic unit, equal to 10E9 light years. This is 9.4605 x 10E21 kilometers (9.4605 yottameters, if you please), 5.8785 sextillion miles (U.S.), 63.240 x 10E12 astronomical units, or 306.595 megaparsecs. In practice, most astronomers use the megaparsec for measuring such stupendous distances. The unit honors the American astronomer Edwin Hubble (1889-1953), who discovered the expansion of the Universe later explained by the Big Bang theory.