Template:Are You Sure/April 15

• ... that astronomer and mathematician Peder Horrebow (14 May 1679 – 15 April 1764) invented a way to determine a place's latitude from the stars?

• ... that mathematician Vera Faddeeva (20 September 1906 - 15 April 1983) pioneered linear algebra; and that her Computational Methods of Linear Algebra (1950) was widely acclaimed?

• ... that physicist Johannes Bosscha Jr. (18 November 1831 – 15 April 1911) researched galvanic polarization and the rapidity of sound waves; and that Bosscha was one of the first (1855) to suggest the possibility of sending two messages simultaneously over the same wire?

• ... that Titanic Maru is an international shipping logistics horror film narrated by Cthulhu?