An "ell" is an antiquated unit of length that has been historically used in various countries, including England, Scotland, and Germany. The length of an ell could vary depending on the region and the specific purpose, but it was typically used to measure cloth or textiles. The term "ell" is derived from the Latin word "ulna," which means "forearm," as the length of an ell was often based on the length of a person's forearm.
Different regions had their own variations of the ell, but some common measurements include:
English Ell: In England, the English ell was approximately 45 inches or 1.143 meters.
Scottish Ell: In Scotland, the Scottish ell was longer, measuring around 37 inches or 0.94 meters.
French Ell: In France, the French ell, also known as the aune, was used and had its own variations, but it was typically around 1.188 meters.
Flemish Ell: In parts of Europe, including Belgium and the Netherlands, the Flemish ell was used, which was approximately 27 inches or 0.686 meters.
A megaparsec (Mpc) is a unit of measurement used in astrophysics and cosmology to express vast distances on cosmic scales. It is equal to one million parsecs. A parsec (pc) is a unit of length used in astronomy to describe astronomical distances, and it is approximately equal to 3.09 × 10^16 meters or 3.09 × 10^13 kilometers.
So, a megaparsec is equivalent to:
1 megaparsec (Mpc) = 1,000,000 parsecs (pc)
Megaparsecs are typically used to describe distances between galaxies and galaxy clusters in the universe. Since astronomical distances are extremely large, the parsec and its multiples, such as the megaparsec, provide a convenient way to express these distances without dealing with unwieldy numbers of kilometers or light-years. Cosmologists often use megaparsecs when discussing the large-scale structure of the universe, the size of galaxy clusters, and the expansion of the cosmos.