In 1936, mathematician Karl Pearson died. Karl Pearson was a leading founder of the modern field of statistics. Teaching graphical methods at University College in London formed the basis for his original interest in statistics. Learn more at http://www.britannica.com/EBchecked/topic/448102/Karl-Pearson

In 1962, the U.S. rocket Ranger IV landed on the far side of the Moon. While the Russians had achieved this feat in 1959, this was the first time an American spacecraft had successfully reached the Moon. Learn more at http://www.impactlab.net/2007/04/26/1962-first-us-rocket-lands-on-moon/

In 1954, the first solar battery was announced. Funded by Bell Laboratories, three American researchers, Gerald Pearson, Calvin Fuller and Daryl Chapin, designed a silicon solar cell capable of a six percent energy conversion efficiency with direct sunlight. Learn more at http://inventors.about.com/od/sstartinventions/a/solar_cell.htm

In 1981, the IBM PC was introduced. The home computer market was emerging in the early ’80s. IBM had intended this model to be a stop-gap computer that would allow them to quickly tap into this market while taking the time to develop a “real”

In 1971, Soyuz 10 launched and became the first spacecraft to dock with a space station (Salyut 1). A soft docking was accomplished. However, the crew could not achieve a secure enough docking to allow entry into the station. Learn more at http://historicspacecraft.com/soyuz.html

In 1991, Intel released its 486SX chip. At $400, the 486SX chip was designed to stimulate demand in the whole spectrum of computers, from palmtop PCs to supercomputers. Read more about the history of microprocessors at http://oz.plymouth.edu/~harding/historymicro.html Photo: Steven White

In 1828, Noah Webster published the first edition of his An American Dictionary of the English Language. In an attempt to make them more phonetic, Webster changed the spelling of many words. Many of the differences that exist today between American English and other English