Infinity symbol Infinity symbol The infinity symbol (sometimes called the lemniscate) is a mathematical symbol representing the concept of infinity. The shape of a sideways figure eight has a long pedigree; for instance, it appears in the cross of Saint Boniface, wrapped around the bars of a Latin cross. However, John Wallis is credited with introducing the infinity symbol with its mathematical meaning in 1655, in his "De sectionibus conicis". Wallis did not explain his choice of this symbol, but it has been conjectured to be a variant form of a Roman numeral for 1,000 (originally CIƆ, also CƆ), which was sometimes
Pearson symbol Pearson symbol The Pearson symbol, or Pearson notation, is used in crystallography as a means of describing a crystal structure, and was originated by W.B. Pearson. The symbol is made up of two letters followed by a number. For example: The two (italicised) letters specify the Bravais lattice. The lower case letter specifies the crystal family, and the upper case letter the centring type. The number at the end of the Pearson symbol gives the number of the atoms in the conventional unit cell. IUPAC (2005) The letters A, B and C were formerly used instead of S. When the