The Story of the Youth Who Went Forth to Learn What Fear Was The Story of the Youth Who Went Forth to Learn What Fear Was "The Story of the Youth Who Went Forth to Learn What Fear Was" or "The Story of a Boy Who Went Forth to Learn Fear" () is a German folktale collected by the Brothers Grimm. It is tale number 4 in the collection. It was also included by Andrew Lang in "The Blue Fairy Book" (1889). The Grimms' first, 1812 edition contained a much shorter version, "Good Bowling and Card Playing" (). It is classified as its own Aarne–Thompson index type 326 of a male protagonist's unsuccessful
Proof that π is irrational Proof that π is irrational In the 1760's, Johann Heinrich Lambert proved that the number (pi) is irrational: that is, it cannot be expressed as a fraction "a"/"b", where "a" is an integer and "b" is a non-zero integer. In the 19th century, Charles Hermite found a proof that requires no prerequisite knowledge beyond basic calculus. Three simplifications of Hermite's proof are due to Mary Cartwright, Ivan Niven, and Nicolas Bourbaki. Another proof, which is a simplification of Lambert's proof, is due to Miklós Laczkovich. In 1882, Ferdinand von Lindemann proved that is not just irrational, but transcendental as well.